Saturday, July 16, 2011

A Visit To Vesta


Via Sky & Telescope comes word that the Dawn probe has reached the asteroid Vesta, going into orbit around it last evening (PDT). Unlike the abrupt arrival burns of chemfuel rockets, Dawn's arrival was a gentle transition from solar orbit to circum-Vesta orbit - the first arrival burn by an electric-drive spacecraft.

The image, taken a week ago by one of Dawn's cameras, shows Vesta as a suitably transitional object, not quite spherical, but also not potato-shaped like smaller asteroids. According to the S&T news note, Vesta probably underwent partial internal melting during its formation, and so has a distinct core and mantle. One of Dawn's tasks is to measure Vesta's mass - implying that we don't actually know yet precisely when Dawn entered Vesta orbit, only that at some point during its gradual burn it must have done so.

Dawn will spend about a year orbiting Vesta before moving on to the asteroid belt's sole full-fledged 'dwarf planet,' Ceres.

This coming week we will return to the vexed issue of reaching Earth orbit. (Yes, last week slipped past me.) But for now, let this be a reminder that exploration of the Solar System is underway and continuing.




In other news, a belated note that I have added my Twitter feed to the right-hand column on the main page, below the archive links. But I haven't taken time yet to add the little bird logo.

93 comments:

Brian/neutrino78x said...

Humans will walk on that asteroid one day :-)

Anonymous said...

Chemical rockets and electric spacecraft...pretty much what we can expect for at least a few decades. Would be nice to see manned missions to various places around the Solar System.

Ferrell

Anonymous said...

Offtopic time.

Rick, guys, I've began reading this blog about a year or a year and a half ago. I believe, I've found a link on ProjectRho, read the first entry... and kept on reading till this, 252-nd one.

Why am I telling this? I just wanted to say thanks for great time spent here. You, Rick, and local community are great read.

From Moscow with love.
And railways.

Tony said...

From a technological perspective, this is an investigation that needed a high Isp, restartable propulsion system to be possible. So it does represent an advance in capabilities of sorts.

Thucydides said...

Looking much farther in the future (when someone wants to walk on an asteroid) we need high density energy sources for the engine. It seems we are getting closer to the magic 1 Kg/Kw figure:

http://nextbigfuture.com/2011/07/high-energy-density-nuclear-power-for.html

It is nice to see the engine part of the equation is now definitively demonstrated.

Tony said...

Re: Thucydides

As always, NBF takes a paper engineering based on presumed -- not demonstrated -- performance and casts it as real technology. Big sigh.

Paul D. said...

Looking much farther in the future (when someone wants to walk on an asteroid) we need high density energy sources for the engine.

Beamed power, perhaps even coupled with laser cooling of the vehicle's radiators.

Citizen Joe said...

What's the opinion on metallic Hydrogen and metallic oxygen? Speculation says that it would be much more efficient as rocket fuel.

Keep in mind that there are HUGE engineering hurdles of cooling and pressurizing those gasses to metallic states.

Assuming after all the additional plumbing, we get a 50% boost in thrust, how does that effect the rocket equation. This model may be analogous to the solid rocket boosters of the space shuttle, where they are semi-reusable.

Anonymous said...

=Milo=



If metastable metallic hydrogen is possible, then I expect it'll come in handy. If it isn't, then nevermind.

Currently we have not yet made metastable metallic hydrogen, nor have much of an idea how to do so.

Tony said...

Metallic propellants are a pig in a poke. It is presumed that their density would allow a great reduction in tankage mass. But, even if they could be made stable enough for use in rocketry, they would still have to be contained somehow, their onboard conversion to liquids for use in engines somehow safely managed, and, once converted to liquids, they possess no more energy per unit mass than they ever did.

Yes, I know that the prediction for metastable metallic hydrogen is that it would release its metallic binding energy as well as its chemical energy when burned with oxygen. Unfortunately for the junior rocketeers, this isn't a gain in efficiency as a fuel, it's a materials handling problem. All of that binding energy has to be controlled to be utilized. at the likely temperatures involved, the realized liquid substance would have to be used as a coolant for the expansion vessel, turning it inot a gas, requiring more energy to be recondensed into a liquid for use in a rocket motor. Or if you just used the release in binding energy as your heat source and the realized substance as your reaction mass, is that really going to release as much energy over time as just burning the liquid with some oxidizer? And all of this is predicated on being able to manage the phase change safely and reliably to begin with, using relatively light mechanisms that could be built into a rocket stage.

So you get no real increase in energy per unit mass of propellant, balanced against material handling challenges that don't seem likely to be solved ever. And we can't wave our hands and say that that's all just engineering detail.

Tony said...

Now here's a thought for metalic hydrogen utilization -- an Orion type engine. Of course, how big a boom do you get out of a given slug of substance, how do you control it so that it doesn't go boom inside the ship, and how do you make it go boom outside the ship? And with the state Isp of 1700, how much thrust is that anyway, per unit of substance?

jollyreaper said...

I like the uncertainty of arrival bit. :)

Rick said...

Welcome to a new commenter, and thanks for the links! Fast trains, or even slow ones, are always welcome here!

I do encourage commenters to use a name or handle - it can just be signed at the bottom, so we know who is who.


Humans will walk on that asteroid one day

For a fairly loose definition of 'walk', given Vesta's surface gravity of 0.022 g!


I have to agree that Next Big Future tends to have a large hype quotient. :-(

The relatively good news is that for the generalized ideal case (flat space), travel time scales as the inverse cube of power density, so even ~10 kg/kW starts to yield kinda sorta decent performance.

Metallic hydrogen - if it could be produced in bulk and handled safely, a couple of very big ifs - would have enormous implications. But evaluating the prospects of this is waaay above my chemistry pay grade.

I would say that it is nothing to count on. On the other hand, a quick read of Wikipedia suggests that it can't be absolutely ruled out.

Tony said...

jollyreaper:

"I like the uncertainty of arrival bit. :)"

Vesta doesn't have any satellites visible from Earth to give us an idea of its gravitational mass. And it's too small to measurably perturb the orbit of anything else we can observe. So we take a best guess as how much it should mass, given the known densities of a few similarly composed Earth-crossers that we've gotten spacecraft to. Then we figure on that basis when orbit should be achieved.

It's definitely not exact science, but guess what, now we have an observable satellite of Vesta -- the Dawn spacecraft. Of course, we're observing it in the radio spectrum, but we know how to use that to get pretty precise state vectors.

Anonymous said...

=Milo=



Tony:

"Unfortunately for the junior rocketeers, this isn't a gain in efficiency as a fuel, it's a materials handling problem."

Well duh. The more energy a fuel carries, the more careful you have to be with it to avoid releasing the energy the wrong way. Is there something new here?


"Now here's a thought for metalic hydrogen utilization -- an Orion type engine."

How does metallic hydrogen help with that? Do you want a metallic deuterium-tritium layer in order to increase the efficiency of the fusion reaction, or something?

I doubt a pure metallic hydrogen explosion, with no nuclear reaction components, would produce a bigger boom than a nuclear explosive of the same mass.



Rick:

"For a fairly loose definition of 'walk', given Vesta's surface gravity of 0.022 g!"

So the question is: just how much delta-vee can humans apply to themselves by jumping, and how low would the gravity have to be for you to be able to jump into escape velocity? That would pretty much place the limit of what surfaces can be "walked" on and what can't.

In such low gravity, though, walking motion as such would likely be less efficient than hopping, skipping, or slow-motion running. You would appear to spend most of the time in the air (or off the ground, since the place you're on doesn't have air), occasionally giving yourself another shove off the ground to keep you going.

Citizen Joe said...

Ya, the Orion type drive was what I was getting at. Prepare metallic hydrogen/metallic oxygen pellets so that they are pretty much cryogenically frozen bombs mid explosion. Then eject them and let them blow.

Of course, I think we'd still need some sort system for getting us up about a hundred feet first, then start dropping bombs.

Anonymous said...

=Milo=



Citizen Joe:

A hundred feet? The Great Pyramid of Giza, made in the 26th century BC, is 480.6 feet tall. Just build a launch platform and use an elevator or crane to get up there.

Tony said...

Milo:

"Well duh. The more energy a fuel carries, the more careful you have to be with it to avoid releasing the energy the wrong way. Is there something new here?"

It depends on how you plan to utilize the energy. If you want to use metallic propellants because they would reduce tankage mass, but plan to use the propellants as normal chemicals in an actual rocket, then converting them from metals to liquids is an onboard materials handling issue of unprecedented dimension. If you plan on using the release of binding energy as the source of heat, while using the resultant gas as a mere reaction mass, that is also a materials handling issue that we've never addressed before. Which brings us to:

"How does metallic hydrogen help with that? Do you want a metallic deuterium-tritium layer in order to increase the efficiency of the fusion reaction, or something?"

Let's not be so literal, okay? I was talking about Orion in general form, not Orion as originally intended. The idea is to make a virtue out of a vice by taking advantage of the solid, stable (hopefully) nature of metallic hydrogen and using it in a mechanism designed for discrete, rather than continuous, propulsion events.

"I doubt a pure metallic hydrogen explosion, with no nuclear reaction components, would produce a bigger boom than a nuclear explosive of the same mass."

That's not the point. The point is that if you have a solid fuel component of some type, that releases energy very quickly and violently, the Orion mechanism is probably the only way to utilize it effectively. Of course, mere chemical energy explosions probably won't provide that much thrust, perhaps not even a 1.0+ vehicle thrust to weight ratio. Given the theorized 1,700 sec Isp quoted from time to time for metallic Hydrogen, it's not likely. (Because the higher the Isp, the lower the thrust, all other things being equal.)

Citizen Joe said...

I'm also talking about using metallic oxygen as well. So it is pretty much the same as the liquid hydrogen/liquid oxygen propellant, except different in just about every way :) I'm also essentially proposing that the metallic forms get blended in ideal ratios and portioned into discrete units. The hope is that it yields sufficient improvement in efficiency to justify its use while not scattering nuclear waste across the entire launch area.

neutrino78x/brian said...

Geez, you guys are even putting a human mission to an asteroid in the implausible category??? Come on!! :-O

I don't see any reason why we couldn't land humans on asteroids using current technologies. :-O

Lockheed Martin thinks it is plausible, and has a plan for such a mission here (link opens a PDF on the LM site):

http://tinyurl.com/27ae4sx

Basically they would link two Orions together, and add an Earth Departure Stage. :)

NASA should be able to do it within their current budget. Just buy two orions from Lockheed, launch them with Commercial, then launch a fueled earth departure stage with commercial, then send humans to go inside it with Commercial. Not that hard, compared to, say, landing on the Moon, which we did in 1969. :)

--Brian

Tony said...

neutrino78x/brian:

"Geez, you guys are even putting a human mission to an asteroid in the implausible category??? Come on!! :-O"

To a main belt asteroid? Not for decades, perhaps centuries.

"I don't see any reason why we couldn't land humans on asteroids using current technologies. :-O

Lockheed Martin thinks it is plausible, and has a plan for such a mission here (link opens a PDF on the LM site):

http://tinyurl.com/27ae4sx

Basically they would link two Orions together, and add an Earth Departure Stage. :)"


The Plymouth Rock mission concept is a very modest extension of Apollo era capabilities. It's not "going to an asteroid" in the sense of Heinleinian romance. It's going to a very small piece of relatively local space junk just a few million kilometers away.

"NASA should be able to do it within their current budget. Just buy two orions from Lockheed, launch them with Commercial, then launch a fueled earth departure stage with commercial, then send humans to go inside it with Commercial. Not that hard, compared to, say, landing on the Moon, which we did in 1969. :)"

If you've read the LockMart white paper you linked to, you'de know that the mission concept requires a super-heavy lifter to get the Earth departure stage in orbit. To do it with currently operational heavy lifters would require two and perhaps three missions just to put enough delta-v in orbit for an equivalent Earth departure. This is where you get into propellant depots, because you need a non-bleedoff storage space on-orbit for all of the fuel that you can't lift with the actual stage. This would extend the mission over several months worth of launches and tricky on-orbit operations, using techniquest that have never been demonstrated before. Or you use at least one super-heavy lifter and do it in two launches that can be very cloesly spaced, because the manned crew vehicle will use a heavy lifter pad of some description, while the spare crew vehicle and the departure stage will use whatever pad (probably a reconfigured 39A or 39B at CCAFS) that the future super-heavy lifter uses. In any event, there's no "[j]ust" involved, in any way, shape, or form.

Brian/neutrino78x said...

Tony, you are SUCH a pessimist! Next you're going to claim that the laws of physics prevent us from going to an asteroid. ((roll eyes)) Geez! If it is physically possible to go the Moon with chemical rockets, I assure you that we can go to an asteroid. And yes, going to an asteroid is going to an asteroid, whether it is an NEO or a main belt object.

I never said anything about Heinlein or anything like that. I don't even like Heinlein compared to Ben Bova's Grand Tour books, which are Hard SF!! I recently read Stranger in a Strange Land, and I can't believe anyone enjoyed that book!!! :-O Incoherent garbage imho, I agree with the reviewer who said that when it was written! ;-)

Stephen Baxter, who has degrees in engineering and mathematics, from Cambridge, making him an authority on this subject, wrote a Hard SF book where men went to Titan using chemical rockets. It's a very entertaining book, once you get past some of the dry engineering parts.

It is quite possible to go to not only an NEO, but also to the Asteroid Belt, using plain H2/O2 propellent. You won't get there as quick as you would with a nuclear thermal rocket, fusion rocket, etc., but you could get there.

Yeah, the LM document does speak of heavy lift, because they were writing in the context of Constellation. However, heavy lift is not required if you assemble in LEO.

The Delta IV Heavy option, used to launch a military satellite in 2007, is quite capable of lifting an Orion (yes, I know that if there are people on it, NASA wants it to be "man rated". They should be man rating as many rockets as possible right now. I've heard that the Atlas V is supposedly capable of being man rated, so you could use that for the crew launch). Orion + service module, total mass 21 MT, Delta IV payload to LEO, 22 MT, according to wikipedia. So, two of those launches, you now have two Orions in orbit. Link them together. Now all that's left is to lift an Earth Departure Stage, dock it with the two Orions, and then lift the humans in a separate launch. That's basically four Delta IV launches.

Now you have everything you need to get to an asteroid, and you never had to develop a new rocket. The only thing that might need to be developed is the EDS, although it seems to me that competent engineers (NASA of 1969 rather than 2011) should be able to integrate the appropriate parts.

btw the idea that heavy lift (as in the new Shuttle Derived Space Launch System)is needed is something that is heavily debated among people with physics degrees on nasaspaceflight.com and other places...so I'm not the only one who thinks we don't need it. Having it is great, but not needed; we shouldn't wait for heavy lift before doing missions.

--Brian

Tony said...

Brian/neutrino78x (1):

"Tony, you are SUCH a pessimist!"

No, I'm a realist. I've thoroughly studied the history of the technologies in question and I understand how they wrok at more than the coffee table book and breathless enthusiast interdweebs discussion group level.

"Next you're going to claim that the laws of physics prevent us from going to an asteroid. ((roll eyes)) Geez! If it is physically possible to go the Moon with chemical rockets, I assure you that we can go to an asteroid."

I would never claim that it is impossible to send people to asteroids. I would absolutely assert that it is a lot harder and a lot more expensive than you seem to think.

"And yes, going to an asteroid is going to an asteroid, whether it is an NEO or a main belt object."

No, it's not. Aside from the obvious astrodynamic issues, NEOs -- especially the very small ones contemplated by the Plymouth Rock mission proposal -- are probably significantly different in composition and structure than main belt asteroids. They certainly present different rendezvous and exploration challenges than something like Vesta or Ceres, which will probably be our first targets for manned main belt exploration.

I never said anything about Heinlein or anything like that..."

I strongly recommend that readers stick with earlier Heinlein (i.e. prior to 1960) and leave off Bova entirely. Also, Bova's Grand Tour series is not hard SF. It's a millions of words of fantasy in an SF setting.

Tony said...

Brian/neutrino78x (2):

"Stephen Baxter, who has degrees in engineering and mathematics, from Cambridge, making him an authority on this subject, wrote a Hard SF book where men went to Titan using chemical rockets. It's a very entertaining book, once you get past some of the dry engineering parts."

To paraphrase Stormin' Norman, Baxter is not a propulsion engineer, neither is he a structures expert, life support expert, guidance and navigation practitioner, nor a trajectory analyst. Other than that, he's a great rocket man. I've never read the book, but judging by the Wiki description, it's full of engineering and astrodynamic nonsense, plus a bunch of typically supercilious British academic middle class attitudes towards America and Americans. I would suggest against invoking it in the future in support of any argument you deem to be serious.

"It is quite possible to go to not only an NEO, but also to the Asteroid Belt, using plain H2/O2 propellent. You won't get there as quick as you would with a nuclear thermal rocket, fusion rocket, etc., but you could get there."

It's possible to go to the main belt using chemical rocketry. It's also very resource intensive and expensive. The delta-v requirement is twice that of Mars, and given the required length of propellant storage on the mission would probably only be achievable with a very large ship using several relatively inefficient storable propellant stages. That, or a cryogenic propellant management system that would be a mass and efficiency penalty all by itself. Yes, you could get there, but only if you had a few spare tens of billions of dollars to throw at a single mission.

Tony said...

Brian/neutrino78x (3):

"Yeah, the LM document does speak of heavy lift, because they were writing in the context of Constellation. However, heavy lift is not required if you assemble in LEO.

The Delta IV Heavy option...

Now you have everything you need to get to an asteroid, and you never had to develop a new rocket. The only thing that might need to be developed is the EDS, although it seems to me that competent engineers (NASA of 1969 rather than 2011) should be able to integrate the appropriate parts."


One couldn't launch a sufficient EDS on a single heavy LV. It would require several launches to orbit either enough fuel in a propellant depot, plus a large, empty EDS to use the propellant, or enough fueled stages to achieve the required delta-v. But this causes some pretty serious operational issues. A single EDS of the right kind can provide all of the necessary impulse in one relatively short burn, but it requires the development and implementation of orbital propellant depot technology, which is neither a simple nor a sure thing. Multiple storable propellant stages (I'd be personally very conservative and base these stages on a stretched -- in both the longitudinal and radial dimensions -- Delta-K) would require a series of two or three perigee kicks, using one to two stages on each kick. This is no doubt doable, but presents the health risk of multiple passages through the Van Allen belts on the outbound leg of the trip, as well as extra operational time on life support and nutritional resources.

BTW, NASA (and contractor) engineers are manifestly not incompetent. They managed a 98.5% success rate on the most complex launch vehicle ever flown. They've just been attrociously managed for the last 35 or so years. That is not, however, a unique NASA trait. The Soviets retired Feoktistov rather than listem to him criticise Buran as a waste of resources.

"btw the idea that heavy lift (as in the new Shuttle Derived Space Launch System)is needed is something that is heavily debated among people with physics degrees on nasaspaceflight.com and other places...so I'm not the only one who thinks we don't need it. Having it is great, but not needed; we shouldn't wait for heavy lift before doing missions."

Once again, a physics degree does not make one any more of an astronautical engineer than my information systems degree does. Among interested laymen with a basic education in the physical sciences, we're all equal except for the serious study we've done in the technologies. And it turns out that physicists have a high enough math pay grade in theory, but don't know much about practical application. Rocket science is not really science at all, you see -- it's engineering.

In any case, the reason you develop super-heavy lifters is that you minimize risk by minimizing launches, and you also minimize risk by minimizing critial maneuvering events (i.e docking and assembly) on-orbit. You also minimize on-orbit storage, which is also important. Finally, you minimize the industrial base on the ground, because multiple, serial launches of heavy lifters would necessitate the construction of multiple pads, larger assembly buildings, and manning of all of that. If all you're interested in is moving ahead as quickly as possible and indefinitely with current LVs, that might make some sense. But if you're interested in what super-heavy capabilities can do for you in the future, you do wait for them to be developed.

There's no time limit on space exploration. Only youthfull impatience and the selfish desire to see it all happen before one dies makes it seem like there is.

Brian said...

Tony, I would never wait for some future technology. I think you said you were in the surface Navy; I can't speak to that, but on submarines, the culture was to make the most with what you have. So if the reactor goes down, you make do with the battery, or if you can snorkel (if you're not worried about being detected at the time), you use the diesel. If the sound powered phones go down, pass commands watch station to watch station. If sonar goes down while submerged, use the underwater telephone as a sonar set. So, I would argue, we should always make the best use of what we have at the time. If better technologies become available later on, we should use them, but not wait 100 years to go to Mars because a fusion rocket hasn't been developed. You can wait forever doing that, man.

But anyway, you said it would take a lot of fuel to go an asteroid. That's probably true, although an NEO asteroid would probably take less fuel than a main belt object. According to these sites:

http://arxiv.org/abs/1105.4152
http://tinyurl.com/3hz5xpl

(scientific paper arguing for manned NEO mission, and wikipedia "delta-v budget" entry), it is about the same delta-v (about 4 km/s) to go to a NEO from LEO as to go to the Moon from LEO. Hence, we SHOULD be able to do it with current technology, since we were able to go to the Moon with current technology.

Recall that I'm arguing, you put the capsules in LEO and assemble your spacecraft first (you can assemble it with the resources of the ISS, which we know we can do, or you can do it by remote control, which there is less experience with), then put the fuel to go from LEO to the target. I think the Saturn V had 4 million pounds of fuel or whatever it was mainly to get the stuff from Earth surface all the way to Lunar orbit without refueling. I'm not sure how much fuel it would take to impart a delta-v of 4.4 km/s to two orions which are already in LEO. Maybe you know the appropriate formulas and can share that with us? The guys who wrote that paper seem to know more math than me, and seem to think it could be done.

I certainly agree that a fuel depot would apply to this kind of mission (though, again, I wouldn't wait to build it before going to the moon or an asteroid). A fuel depot, in my mind, would be intended to be used by commercial operations such as asteroid mining, as well.

I almost feel that this should be a USAF mission, because there are national security reasons to do it, and the military seems to be a lot better at making the most of what they have than NASA of 2011.

--Brian

Thucydides said...

If we are going to speculate about this in a sort of realistic manner, then we should see if the mission could be done using the Falcon 9 Heavy architecture.

This is the only near term US heavy lifter (even if the heavy architecture hasn't been flown yet, it is much closer to reality than Ares V or anything else). With a projected payload of 53,000 kg to LEO, we have much more to work with (including Dragon capsules with large service modules and a big transfer stage).

GARY CHURCH said...

Falcon Heavy is pieced together mickey mouse junk. Private space has been hyped beyond belief. Very little of what they are promising is going to work or be worthwhile.

Fuel Depots and fuel transfer is based on storing and transfering liquid hydrogen. The dirty secret is that this is probably not practical. LH2 is extremely difficult to handle and store in space for many reasons and that is why it has never been done. There is no new technology or materials that are going to make the problems any easier to solve than it was a half century ago.

Falcon and dragon have so many bad design features it would take more time than I want to spend listing them here.

The SLS is the only way we are going to go anywhere beyond earth orbit. And LEO is a dead end- endless circles at very high altitude. To be a space traveler you have to go somewhere and circles go nowhwere.

The Moon was and is the first destination and the base from which to launch missions to the outer solar system.

Anonymous said...

Gary Church said:"Falcon and dragon have so many bad design features it would take more time than I want to spend listing them here."

And yet, it has flown at least one successful orbital flight. It is said that perfect is the enemy of good. I would say that almost all the commenters here are frusterated about the lack of progress in space after the Apollo program came to an end, but most of us try to imagine ways to overcome this percived shortcoming. Just to clarify, this blog caters to both discussions about real-world solutions and fictional building blocks for our stories.

Ferrell

Tony said...

Re: GARY CHURCH

You are way over-the-top in your statements. SpaceX's rockets do fly and they do put payloads in orbit. Dragon did achieve a human-survivable flight, even if it was just a couple of orbits and no people were aboard.

I'll agree with you that SpaceX has so far been pretty lucky. But it's also true that oftentimes one makes one's own luck. Still, as they become less startup and more mainstream in nature, they will no doubt adopt industrial and risk management practices similar to Boeing and LockMart. If you ask me, ten years down the road, if they're still around, they'll be just another rocket company. And they'll have the same customers rocket companies have always had -- government and large corporations.

I agree that orbital propellant depots are probably not going to get off the ground anytime soon, but more for astrodynamic than technical reasons. Not that technical questions don't exist, but they serve more to compound the already tough orbital mechanics issues more than they represent outright showstoppers in their own right.

Brian/neutrino78x said...

Thucydides, the Delta IV Heavy Option currently exists and was used to launch a military satellite. It is capable of lifting the Orion (you would launch humans and additional modules, such as boosters, separately).

My whole thing is, if you can't count on heavy lift, or at least you can't count on it happening in a timely, fiscally responsible manner, you work with what you have. You do that by looking at what the capacity of current launchers are, and you design the size of modules accordingly. You also eliminate "cost plus" and do only fixed price and competitive bid.

And I still haven't seen anyone tell us how much fuel would be required to impart a delta v of 4.04 km/s to a spacecraft with the mass of two Orions which is already in LEO. I presume it would be far less than the 4 million+ pounds of fuel which was needed for Apollo 11, since it had to both escape the Earth's gravity well and enter that of the Moon with the same rocket. I admit you actually need to carry more fuel because you need to boost back to get captured by the Earth's gravity well again. But I don't think it would be 4 million pounds....Falcon 9 can go to LEO from the Earth's surface, which I believe takes more Delta V than going to a NEO, and it has a total mass of under 800,000 pounds, so that right there tells you that you shouldn't need 4 million pounds of fuel to go from LEO to a Near Earth Object.

The table of Delta-Vs on this site is easier to read than the one on wikipedia, seems to show that going to a NEO would be less delta-v than going to the moon, from LEO:

http://tinyurl.com/3npzev7

Based on that...should be well within our capabilities with current technologies.

--Brian

Elukka said...

"Falcon and dragon have so many bad design features it would take more time than I want to spend listing them here."

List the most crippling ones, then.

As for SLS... It's designed by congress. Its design is based on politics, not on building a good launch vehicle. It uses huge, segmented solids because congress wants to support ATK. They've been proven to be expensive, but NASA will have to use them whether they want to or not. When they looked into other options, some congressman frothed about how it's against the law.

And remember how the last time went? Ares I, a vehicle much simpler and smaller than SLS, using very similar shuttle-derived architecture... Its estimated development cost was $40 billion. The test vehicle, Ares I-X, literally an expired shuttle booster with dead weight on top, cost nearly half a billion to build and launch. Per-launch costs of the production version were projected at $1 billion by the Augustine commission, if memory serves.

For comparison, Falcon 9 development cost around 0.3 billion. I am not saying SpaceX is the sole answer to the US space program, but it certainly isn't the worst one. There seems to be significant evidence that SLS will end up horrifically expensive, perhaps another quagmire of shuttle proportions.

Elukka said...

Researching a bit on that, it appears NASA is trying to slither out of congress' requirements. The SLS could yet become a system with a shuttle-derived hydrogen core stage but newly-designed liquid strap on boosters.
Renews some hope for me that a good vehicle could emerge out of this!

Tony said...

Let's see...

A new super-heavy lifter -- Shuttle-derived or any other kind -- is not new technology. It's using what we know to reconstitute a capability we've already demonstrated operationally. I'm personally in favor of Shuttle derivation, because it leverages existing experience and maintains an existing industrial base. Just because that satisfies certain political aims doesn't mean that's a bad thing.

As for what it would take to orbit an EDS for a NEO rendezvous, all of the illustrations and descriptions suggest something roughly the same as an S-IVB stage. That means as much as 120 tons and probably not much less than 80 tons, fully fuelled. You're not going to do that with Delta IV Heavy or anything like that. You'll need multiple launches, with all of the technological and industrial issues that entails.

One would have to expand production facilities to meet the launch rate. Whatever lifter one used, one would probably have to expand to at least two pads at CCAFS, more likely three. And all of that would have to be manned in parallel, since the whole point would be to run as many launch campaigns as possible simultaneously.

That may be desirable, as I said earlier, if you plan to do everything into the indefinite future with a bunch of Deltas, Atlases, and Falcons. In fact, I could see a multi-type architecture based on just that -- crew on, let's say, Atlas, with cargo on Deltas and Falcons. It would certainly take advantage of existing parallel capabilities on the ground.

But if your future plans definitely include a super-heavy lifter, then waiting for it to be ready is not that much of a sacrifice. Remember, wanting to do everything right now, as soon as possible, regardless of the cost and future plans, is just a perceived imperative in the minds of people who don't want to miss anything that might happen after they're gone, given a more relaxed schedule.

BTW, Brian, Apollo did not "escape the Earth's gravity well and enter that of the Moon with the same rocket". The S-IVB provided the delta-v for trans-lunar injection. But lunar orbit injection and trans-earth injection were done by the Service Propulsion System on the Apollo Service Module.

brian/neutrino78x said...

Elukka, I don't know, I still think we would be better off just assembling things in LEO, that way we don't need heavy lift. We know from the ISS that NASA can assemble things in LEO. Of course the "SLS" was for political purposes, not engineering. But, if it is going to be built, we might as well use it, and the first use should be to go to an asteroid using Flexible Path. :)

Of course if you have a heavy lift vehicle you can do Mars Direct as originally designed by Zubrin, not having to assemble things in LEO.

I would only want NASA to own a fleet of vehicles if they were fully reusable SSTO rocketplanes, which can be ready for another launch after just refueling them. :)

That, or have NASA own a vehicle that stays in space the whole time, like the Enterprise (though much smaller of course), so you just send people up to it on commercial, have it go somewhere, come back, then the people go back down to Earth on commercial.

We should launch into LEO with commercial a lot because that will stimulate the nascent commercial space industry, which will be a far more sustainable space program! :)

--Brian

Brian/neutrino78x said...

Tony, you didn't really answer the question I was asking though. The plymouth rock mission assumes that we have heavy lift. I was saying, how much fuel does it take to send a dual Orion spacecraft to an NEO, if they are currently in Low Earth Orbit? It would surely be less than 80 tons. Did Apollo use 80 tons of fuel to go from Earth Orbit to the Moon (NEO takes less delta-v than that)? Well, even if it is 80 tons, that's four Delta IV launches, so, still no heavy lift needed.

--Brian

brian/neutrino78x said...

and yes, the Saturn V launched all the vehicles you mentioned, tony, so what I said was correct. Command module, Lunar module, and Service Module were all on the Saturn V stack. See:

http://en.wikipedia.org/wiki/Apollo_11

They needed 4 million pounds of fuel because they were pushing a lot more than what I am talking about.

--Brian

Rick said...

Welcome to another new commenter!

Discussion of near-term technology (as distinct from what we actually have in service) runs into a serious ideological baggage problem. Basically everyone has something to sell, and/or an ax to grind, which distorts perspectives. (I don't claim to be exempt from this, by the way.)

And truth to be told, I don't think it is very relevant to argue detailed architectures of a mission when there is not a snowball in hell's chance of it being funded within the time frame of mission planning.

The flip side of this is that NASA's budget has been in the $15-20 billion range (constant dollars) for about the last 25 years, so that is a stream you can reasonably count on, give or take.

(I am setting aside current Beltway budget hysterics. I'd soon as not go there, but if that is where the commenter community wants to go, I may say the hell with it and express my own views. Y'all have been warned.)

Tony said...

brian/neutrino78x:

"I would only want NASA to own a fleet of vehicles if they were fully reusable SSTO rocketplanes, which can be ready for another launch after just refueling them. :)"

IOW, you only want NASA to own a fantasy.

In any case, when talking about real, expendable rockets, nobody really "owns" them. They order them from the manufacturer, prepare them for operational use, then expend them. I don't think they qualify as capital equipment on the ballance sheet.

"We should launch into LEO with commercial a lot because that will stimulate the nascent commercial space industry, which will be a far more sustainable space program! :)"

As already stated on this blog numerous times, we've always launched with commercially acquired equipment. What you really mean is that NASA should get out of the launch vehicle operations business. Well, for LEO cargo, you're probably correct. But for manned flight, and for exploration, there's no reason NASA shouldn't run its own operations, and no real good technical argument -- as opposed to ideological ones -- why they shouldn't.

"Tony, you didn't really answer the question I was asking though. The plymouth rock mission assumes that we have heavy lift. I was saying, how much fuel does it take to send a dual Orion spacecraft to an NEO, if they are currently in Low Earth Orbit? It would surely be less than 80 tons. Did Apollo use 80 tons of fuel to go from Earth Orbit to the Moon (NEO takes less delta-v than that)? Well, even if it is 80 tons, that's four Delta IV launches, so, still no heavy lift needed."

Two Orions together, with their respective service modules, mass more than an Apollo CSM/LM combination (21t * 2 vs 30t + 5t). Even with slightly lowered delta-v, requirements, you have to get S-IVB class impulse. That means something that masses about 80-100 tons.

Let's say it's 80 tons. Using an orbital propellant depot, you're not just talking about the mass of the propellants, you're talking about the mass of the propellants, plus depot, plus an empty EDS. Figure six launches, at a minimum. Or maybe you use those six launches to put up six storable propellant stages. Or you could just put the fueled EDS on-orbit with just one launch, if you have a super-heavy LV. And don't forget that right at the moment an orbital propellant depot is speculative technology. A super-heavy LV has been done -- twice, actually, counting Energia. It's pure engineering. I wouldn't be so sure that the propellant depot is any closer to reality than a new super-heavy lifter.

"and yes, the Saturn V launched all the vehicles you mentioned, tony, so what I said was correct. Command module, Lunar module, and Service Module were all on the Saturn V stack. See:

http://en.wikipedia.org/wiki/Apollo_11

They needed 4 million pounds of fuel because they were pushing a lot more than what I am talking about."


I watched Neil and Buzz walk on the Moon live. I watched live TV coverage of all of the other manned lunar missions too. All of that happened before you were born. So please don't presume to lecture me about the Saturn V. I responded to precisely what you said, which was factually incorrect. Saturn V actually used two full stages and a partial burn on a third stage to achieve Earth orbit. It used the remainder of the third stage for lunar transfer. (It never actually achieved Earth escape -- if the Moon hadn't been in the right place, the CSM/LM would have gone out 500k km and come back.) It used what was effectively a fourth stage to enter and exit lunar orbit. It didn't use a single rocket to escape the Earth's gravitation influence. That's the real story.

Anonymous said...

Agreed, Rick.
Here's a few topics which might be more interesting than the design of a US manned mission to wherever:

Assuming adequate funding, what's the case for a near-future manned mission outside of the Moon, NEO and Mars (one-way) anyway?

How do you envision the life support (including protection from raidation) for and the lifestyle of near-future interplanetary astronauts?

We can all figure the chances of a US manned mission so what are the chances of a joint Russian/Chinese mission or even of a truely international manned mission to wherever?

-Horselover Fat

Thucydides said...

The funding problem can take care of itself if missions to the Moon, NEO's, Asteroids and Mars are done "X" prize style. The money can be held in escrow until the winner splashes down/glides back to Earth and shows up on the steps of the Capital Building to collecct the cheque in a well publicized ceremony.

This worked to establish the US aviation industry and was replicated with the "X" prize (or any other number of prizes. Remember the Kremer Prizes for human powered flight?)

While in practice only aerospace corporations could compete with any realistic chance of success, there is nothing to say they might not enlist small, innovative companies to cut metal and do the work, or their own internal "Skunk Works" to do the job quickly and cheaply.

Tony said...

What happens when you've been working for five years and the prize legislation is repealled? I can't think of a single aerospace company or consortium of companies (which is what anything beyond LEO would actually take) doing the first bit of work without a contract in-hand.

Rick said...

There's a very important issue of scale here - basically the difference between millions and billions of dollars/euros/whatever.

In terms of the rich nerds out there, $10 million is hobby money. But $10 billion is not hobby money - people only pony up that much on bets they see as likely winners.

Of course they can be wrong, e.g. Iridium. But you didn't have to be a space geek to buy into Iridium; it was basically just another telecom hustle.

Notice how fundamentally conservative SpaceX is. Their basic pitch has not been 'we have a radical new way to get into space,' but rather 'we can develop a conventional expendable booster that will be 10 percent cheaper to fly.'

Enthusiasts love #1. Plain old business interest prefers #2.

Anonymous said...

=Milo=



Thucydides:

"The funding problem can take care of itself if missions to the Moon, NEO's, Asteroids and Mars are done "X" prize style. The money can be held in escrow until the winner splashes down/glides back to Earth and shows up on the steps of the Capital Building to collecct the cheque in a well publicized ceremony."

While this can encourage people to try to win the prize, they are not going to try unless they already have enough capital to be able to afford to perform the mission in the first place, and to be able to spend the money while risking not actually getting the prize (because their development project reaches a dead end, because someone else claims the prize first, etc.).

Anonymous said...

Put $10 billion in a bank account and leave it there until someone wins...that might kickstart a commercal space race. Even if you spend $9 billion, you're still a billion dollars up if you win. Way back in the '70s I read a story about a space race, the winners got a trophy and a monetary prize, but the real goal was to have built the best rocketship available to humans. Maybe that's what we need; appeal to people's vainity.

(and Rick, it's too difficult to scream in frustration over the internet...but if you really want to)

Ferrell

Anonymous said...

What worthwhile mission could possibly be done with 10 gigabucks?
You could perhaps fit two or three cool robotic missions within that budget.
Maybe someone could blow that kind of money on some glorified space tourism jaunt like sending an old Russian craft around the moon a few times.
And maybe the Chinese or the Russians could do something insteresting with that kind of money. I doubt it but I don't know really.
But I don't see how any worthwhile mission involving North Americans or Europeans astronauts traveling beyond LEO could possibly be carried out on 10 gigabucks. Have you heard about inflation?
Sure, NASA could do with 10 extra gigabucks. Maybe the JWST as well as the unmanned mission to Europa could be launched with that. Those are priorities yet they were both cancelled last I heard.
But a worthwile manned space program would require another degree of commitment. Let's get real!

-Horselover Fat

Damien Sullivan said...

Aren't cheap robotic missions like Sojourner in the $500 million range, or even less? Hubble was $1 billion, though some years ago.

Anonymous said...

Cheap robotic missions are in that range. But we're fast running out of targets for cheap but worthwhile missions like Messenger.
Look at the amounts expeneded on the cooler missions like Curiosity (and that's not even launched).
I suppose the cheapest worthwhile mission now would be an Uranus orbiter that can perform relatively close flybys of the moons (like Cassini without a lander).
I'm expecting the full cost of the mission to Europa would have been higher than proposed (as usual). But the latest proposed budgets were heavy enough if you take them at face value!

Hubble cost a lot more than that, around $10 billion in today's money I guess.
And look at the original budget of the JWST and the overruns...

Sure, you can send robots in space fairly cheaply. But for what?
Developing countries might launch missions of dubious scientific value as part of a ramp-up of their capabilites.
But NASA is #1. Why bother launching anything that can't deliver a lot more and/or better data than previous missions? So the bar keeps being raised, and the cost of worthwhile missions with it.

-Horselover Fat

Damien Sullivan said...

Huh, I'd thought Hubble was $1 billion, wikipedia puts total cost more at $5 billion.

But while bigger missions returning more types of data can be cool, I think we're far from saturated in using the stuff we've done already. Every planet and large moon could use an orbiter. Mars has seen a rover or two... which barely scratch the global area. More and more of the same would be informative, because they'd be looking where no one else had. Ditto for Lunar or Mercury rovers, probably.

Mars Pathfinder with Sojourner seems to have cost $280 million. Spirit and Opportunity $800 million for their first 90 days, I'd guess about $1 billion after mission extensions. $3 billion could spam Mars with 10 Pathfinders, or 3 pairs of the later rovers. I doubt that would be uninformative; you don't prospect a planet from a few hectares.

Anonymous said...

You're neglecting inflation and the monies contributed by other countries. The value of the dollar has fallen more than you'd think by looking at consumer prices in recent years.

Every planet between Mercury and Saturn has at least an orbiter except for Jupiter whose next orbiter is now prepped for launch. No targets there, except for Uranus which NASA doesn't intend to do with a simple orbiter (I hope that choice won't make it slip again and again) and Neptune which is currently too challenging.
Worthwhile orbiters for large moons (beside our own) do not come cheap unfortunately. Except for the moons of Uranus and Neptune (see above), they've all benefitted from a good look in the past so you'd need to put a non-trivial payload on the thing.
The priority is Europa obviously, with budget estimates of up to 6 billions for the orbiter. That could be done cheaper but was effectively cancelled instead. For something like 2 billions a piece, orbiters to Enceladus and Io (dicey but interesting) have been proposed. Ganymede was supposed to be a European mission. Other moons do not justify such expense except for Titan but NASA's plans for Titan are so ambitious they're not going to come to fruition any time soon. A Titan lander is apparently seriously considered in the near future however for a modest budget (that would be awesome but I'm skeptical).

Just look at NASA's "discovery" program, the one harboring missions costing less than half a gigabuck (neglecting overruns and extensions).
A load of cool inner system missions have been launched between 1996 and 2005. Look at the list: it's impressive! Since then we've only had Dawn (the one currently orbiting Vesta). Three missions plans are under development (mostly dubious in my uninformed opinion) but the only mission which is going to happen for sure is a pair of Moon orbiters. Quite a contrast to that program's golden age...

As to Mars, people are obviously preferring expensive rovers (like 2 to 4 billions a piece) to a flurry of rovers lacking interesting capabilities. These things are so expensive they're eating the budget of outer system missions only NASA could do. The Russians are doing Mars now (and taking the Chinese with them) and the European have been at it for a while so, considering how little money Congress is allowing to be spent on this stuff, I wish NASA would drop its Mars focus.
There are a few problems with your flurry of rovers:
-Mars has a thin atmosphere so orbital imaging works very well most of the time
-cheap rovers can only deal with favorable terrain so they can only cover some places and not the most interesting ones
-cheap rovers can't do much more than they've already done unless they're landed near a particularly interesting target (and what would that be, besides Opportunity's current target?)
-last but not least: what do want the rovers to prospect for anyway? their capabilites are very limited (compare them to Phoenix and Curiosity)
I'm not saying it would be uninformative but surely one could do better with 3 gigabucks!

Thucydides said...

The primary issue with NASA's cost structure is the "Standing Army" of staff to perform missions. Jerry Pournelle makes a very strong case the reason the Space Shuttle turned out to be so expensive was the political need to keep the 20,000 or so engineers and technical staff + additional aerospace contractors employed by Apollo working. The salary and benefit costs is probably far greater than any number of actual space missions.

The DC-X program was fast and cheap because it had such a small staff and limited overhead (the fact they were trying to build a reusable SSTO notwithstanding), and I'm pretty sure one of the reasons SpaceX can get away with such low costs is low overhead as well (as well as semi production line economies of scale).

An "X" prize would be a big challenge, but Boeing and Lockheed-Martin have internal organizations (Phantom works and Skunkworks) for fast, low overhead work and Northrop Grumman purchased Scaled Composites probably for the same reason. If the chances of success seem reasonable and the corporate hierarchy is supportive (perhaps for prestige or other non monetary considerations) then someone will rise to the challenge.

Tony said...

Re: Thucydides

While Jerry is generally good on his technical stuff, he can't let go of SSTO fo personal philosophical reasons, not because the potential is really there. The "standing army" was there because Shuttle required that much TLC to keep flying. Likewise, DC-X was an experimental program that failed technically because it was poorly staffed and materially supported. Even if it had succeede technically, it was so far from a launch vehicle that it's just not likely it could have been upscaled to work as one. Finally, as pointed out numerous times before, SpaceX is operating with a very conservative design philosophy and employing startup business practices. When it has to have investors and start behaving like a responsible corporate entity, all of those alleged cost savings are going to melt away.

Anonymous said...

The next Jupiter orbiter seems to have been sucessfully launched a few minutes ago. There goes your last cheap target, Damien. Well, it will probably end up costing well over a billion USD...

For those who think the private sector can do it cheaper:
-we're not talking about building rockets to nowhere but doing useful work beyond Earth orbit and no one does that cheaper than NASA
-only one spacecraft has been operated in the outer solar system without major assistance from NASA but it didn't get close to any massive body and no others are being worked on
-only NASA has so far been able to carry out an entire Mars mission successfully (hopefully that will change in the next couple of years)
-NASA uses private sector expertise already when it is available (and when they're forbidden to rely on foreign agencies who might be better contractors)
So please don't push for a re-run of the Soviet space program. This isn't about ideology and posturing anymore. If you want manned missions, a 10-gigabucks X-Prize or whatever else, please start by figuring out a workable plan worth carrying out first. In the meantime let the people who actually know how to get results (not politicians and their pseudo-private cronies) spend public funds.

-Horselover Fat

Thucydides said...

You are putting the cart before the horse. With an incentive like an "x" prise, people will have the motivation to "figur[e] out a workable plan worth carrying out". Without an incentive, they put their energies elsewhere.

Since there is little incentive for doing science projects (except to a very small minority of people), we don't see private venture spacecraft heading out to Jupiter or Neptune. While many of this feel this is an unfortunate state of affairs, this is reality. Many previous threads have examined the issue (now shorthanded to McGuffinite); once some sort of McGuffinite is identified and established as a profitable venture, I'm sure you will see investment monies flow and metal starting to be bent.

Anonymous said...

An incentive for what exactly?
You mentionned a payment on splashdown so the goal you're talking about may be sending human cargo to a NEO and back (nobody is going to come back from Mars and the Moon has been done already). But what would be achieved? Surely you would want the incentive to be for something more than moving cargo around the neighborhood.
If you have no reasonable and productive plan, you'll be giving random, pointless incentives and you'll have yet another program building rockets to nowhere. You might as well waste a stupendous amount of ressources building a deep-water port in Antarctica in the hope of jump-starting a colony there!

McGuffinite is fantasy. Identify some before advocating for spending public money on infrastructure to facilitate its harvesting!

You're fixated on this public/private dichotomy in a context where it makes no sense and missing the point: there have been and are other space agencies, none anywhere as sucessful as NASA in spite of the billions they're spending so maybe NASA is doing some things right in spite of the politicians and the ideologues.

-Horselover Fat

Tony said...

Part of the problem is that ever since the Age of Exploration (which should really be called the Age of Seeking Profit Outside of Europe) it has been demonstrable that doing something the first time makes it psychologically possible for somebody else to do it again. And that freed up money to in fact do it again, many times, because there was a profit to be made.

But space isn't like that. We have the psychological possibilities already accepted by the vast majority of people who care. But there isn't any money to be freed up, because there's no profit to be made. X prizes? Even though he wouldn't say by how much, Paul Allen did admit that winning the prize was significantly more costly than the prize was worth. And that was a relatively small amount of ten million dollars, funded by a "hole in one" insurance policy, and collected by a billionaire who could easily afford the millions of dollars in cost overruns simply for hte notoriety. That won't scale up to billions of dollars and large aerospace corporations.

Money needs a reason to be spent. SOmetimes reasons are frivolous. But when the money starts getting into the tens of billions, frivolity tends to take second place to calculation. And there's no calculation outside of government circles that can justify the expenditure for space.

Finally, I fully realize that many people think that undertaking enough schemes will someday make space access cheaper. Yes, but by how much, and for what? Bipropellant chemical rocketry is a mature technology. There are only marginal gains to be made in performance, both in engineering and cost terms. So technology would have to radically change. There's nothing money prizes could do to change that. And even if costs came down far enough to free up significantly more money -- or just use existing investment levels better -- the money wouldn't be freed up because there's nothing out there to make a profit off of, that doesn't already exist right here.

Thucydides said...

So what is the point you are trying to make? Politicians don't have enough constituents interested in going to Mars to fund any sort of deep space program, so appealing for NASA, the ESA or anyone else to do so is pointless.

Maybe there is McGuffinite out there, our current knowledge of the space environment is slightly better than what European explorers had about North America in the 1500's. They rushed off to seek gold, and ended up finding many new resources and founding many new industries instead. IF there is something like that out there, then the only way to discover it is to actually start looking.

A $10 billion "X" prise costs the taxpayer very little, the money isn't awarded until the winning team meets the conditions and comes to collect, so if no private company steps up to the plate, you are out nothing. IF a private venture does spend their own money and are unsuccessful, only the shareholders are out of pocket.

NASA has managed to accomplish some astonishing things, but as it has become politicized over the years, the ration of success to failure has steadily shifted towards failure. They spent billions of dollars on the Constellation system and got exactly nothing, and have floundered for literally years in trying to define a new mission or build a new platform.

An X prize can stimulate new thinking and new approaches, which is the major benefit (the Spirit of St Louis wasn't anything new, just an airplane which was better designed and built thn previously, same as SpaceShipOne, it just put many existing technologies together in new ways). Funneling money through a small bureaucratic bottleneck limits the number of approaches that can be tried and ultimatly slows the process of innovation as effort is shifted to gaining control of the money.

Tony said...

Thucydides:

"So what is the point you are trying to make? Politicians don't have enough constituents interested in going to Mars to fund any sort of deep space program, so appealing for NASA, the ESA or anyone else to do so is pointless."

That's basically why the Augustine Commission recommended Flexible Path. NASA can still make incremental improvements in capability on a limited budget. Eventually, by making incremental improvements, you get where you want to go. Call it the Henry the Navigator Plan.

Also, I wouldn't say politicians and their constituents are out y'all. The current Space Launch System program was basically mandated by Congress, after all. Yes, it's being legislatively led by representatives and senators with aerospace constituencies, but Congress as a whole could easily have opted for nothing more than continuous orbital ops with COTS-derived LVs. Instead they chose to develop an LV with exploration as its primary design objective.

"Maybe there is McGuffinite out there, our current knowledge of the space environment is slightly better than what European explorers had about North America in the 1500's."

That's simply not factual. The unknown resources and markets had everything to do with the existence of horizons and lack of prior reconnaissance. In space there are no horizons, and we've actually done plenty of reconnaissance. There aren't any unknown markets, and since we've developed satellite-based resource survey techniques, there are likely not many unknown resources.

"A $10 billion "X" prise costs the taxpayer very little, the money isn't awarded until the winning team meets the conditions and comes to collect, so if no private company steps up to the plate, you are out nothing. IF a private venture does spend their own money and are unsuccessful, only the shareholders are out of pocket."

Uh-huh...how do you justify to your shareholders the cost overruns (WRT the prize) even if you win the prize? And if an organization doesn't win the prize, it's not just the shareholders that get gouged, it's customers, employees, factory town businesses, etc. TANSTAAFL.

"NASA has managed to accomplish some astonishing things, but as it has become politicized over the years..."

NASA has floundered, but can you name a fundamental reason that it can't return to an exploration focus for manned spaceflight? If the politicians are for once at least a little bit consistent over the next ten years, NASA will have a fully developed exploration class LV. With that, even goofing around in Shuttle era fashion, just by using the thing they'll accomplish some worthwhile objectives.

"An X prize can stimulate new thinking and new approaches..."

Long on philosophy, short on technical, political, and economic reality.

Damien Sullivan said...

I saw $1.1 billion on wikipedia for final Juno cost. So, one Shuttle launch, or the heaviest probe ever (I think with the largest solar panels to brave Jupiter's radiation belt for a year.

I suppose it really almost nothing to have prize money promises hanging out there; OTOH, I wouldn't expect much radical progress from them.

Columbus set sail to have trade with China; it was a good and profitable plan apart from getting planetary size wrong. Gold and silver were soon found instead, which drove profit, and then furs and other goods, and land was an obvious draw to an agrarian society. The Age of Exploration wasn't about pure exploration until maybe Cook, but was driven by very concrete and reasonable expectations of profit.

We have an excellent idea of what's out in space, especially compared to our expectations of what could possibly be there worth extracting. And we're still poking around, so if there's some cache of magnetic monopoles or other McGuffinite we still have a chance of finding it.

Use of "once some McGuffinite" rather than "if some McGuffinite" seems rather telling.

"there have been and are other space agencies, none anywhere as sucessful as NASA in spite of the billions they're spending"

Hrm. Soviet/Russia seems quite *successful*. They're the ones with Mir and Soyuz and Venusian landings. ESA has a fair range of probes of its own, and Arianespace; seems quite successful. NASA may do more, but NASA gets more money, from a bigger single research purse. They all seem fairly successful given their resources, and modulo wrong turns.

Anonymous said...

"Politicians don't have enough constituents interested in going to Mars to fund any sort of deep space program, so appealing for NASA, the ESA or anyone else to do so is pointless."
Huh? NASA, Russia and China are prepping for launch as we speak. Mars is quite a popular destination even if everyone but NASA keeps failing their Mars missions. Even Finland has its own Mars program!
It's not all that expensive or challenging to go to Mars actually, just deadly. What would be very expensive and challenging, and I'll say this one last time since it is a very important distinction, is to do useful work there. The time when simply going there was justification enough is long past for the USA. Give people a good reason to go there!
China (whose politicians care even less about their constituency than yours) on the other hand may ask its astronauts to sacrifice their lives pointlessly in order to prove its technological and military capabilities. If rockets to nowhere is what you want, look to Asia!

"Maybe there is McGuffinite out there ... then the only way to discover it is to actually start looking."
Rockets to nowhere can't find anything. That's not looking!
None of the private space ventures which have resulted in the spending of not inconsiderable amounts of capital have been looking for anything. The only manned mission remotely relevant to finding anything since Apollo was the repair of Hubble. Looking is best done by robots, at least until you have found a serious prospect warranting a manned expedition.
Meanwhile NASA has been looking in more places than ever in the last 15 years or so, as have the ESA and JAXA. Surely you can't have failed to notice all the small bodies they've visited, shot at and landed on. You must know that anything which might be extracted from such bodies in the future wouldn't have to be lifted from our gravity well. And while you may dismiss the exploration of the Saturn system as uneconomic because it's so far away, you have to reckon Mars and especially the Moon have been looked at with an eye towards the easily exploitable resources these bodies might offer in recent years. Yet you don't acknowledge any of this. Why?

"They spent billions of dollars on the Constellation system and got exactly nothing, and have floundered for literally years in trying to define a new mission or build a new platform."
Constellation was always going to be a failure. Its stated goals were driven by politicians famous for ignoring reality.
Most of NASA's budget has been wasted on political rockets to nowhere. It's always been that way. NASA's useful work is done on a small fraction of its total budget.

"An X prize can stimulate new thinking and new approaches"
An X prize needs an objective. What are you going to reward again? It kind of matters.
The X prize you referenced instead of stimulating new thinking rewarded a specific and fruitless approach for instance.

-Horselover Fat

Anonymous said...

$1.1 billion was indeed the figure bandied about at Juno's launch. But unless the orbiter fails early, I'm expecting the final cost to be significantly higher as usual.
Rosetta has panels of similar size but arranged differently which gives it a longer wing span. And Juno's only the heaviest probe ever if you rule out a number of crafts based on their nationality and payload. Some Soviet orbiters were really heavy, even those which did not carry landers. But regardless: it's indeed large and heavy compared to plutonium-powered probes.

My point was certainly not that NASA's robots are excessively expensive compared to other expenses of the Federal government. They're built and run on a small fraction of NASA's budget which is not all that impressive to begin with.
My point was that robots that can achieve something notable tend not to be as cheap as they used to be. Exploration funding (which is not the same thing as the space funding) will have to be increased over time in order for progress to be kept up.
There's probably a place for (ultra-)cheap robots in the future like engine-less solar sails. But such designs are very limited.

Yes, space agencies other than NASA have not been entierly useless and I'm hoping they will improve but you've got to reckon the achievement gap is rather large (see my previous posts), and certainly not commensurate with the funding gap (NASA's budget must be a bit less than twice the European budgets if you add them up).
What are the achievements of the other agencies outside of Earth orbit (Moon included)? Not counting the ESA probes and payloads launched and delivered by NASA, there's the Veneras, Giotto, Venus Express, and a bunch of partially failed missions. Am I forgetting anything? I would be disappointed if a couple of notable additions to this list were not made in the next few years but it's not all that impressive right now.
Soyuz and Mir are useless for exploration and Ariane's just a launcher. The tricky part is not the launching. Launching rockets to nowhere is something many agencies are indeed very experienced at.

-Horselover Fat

Anonymous said...

I would specify that one of the 'X'-prizes be a 'race' from Earth's surface to Mars orbit and back to Earth's surface; cost, time, reliability, and payload mass. Another 'race' could be from Earth surface to orbit, back again, and then back to orbit; again, cost, time, reliability, and payload mass would count(you wouldn't need to reuse the booster stages, just the passenger/payload module). Another 'race' could be from Earth orbit to Lunar surface and back again; cost, time, reliability, and payload mass would all count.

Does that satisfy everyone's questions about specific goals for this new X-prize? If any of you have ideas for different 'races' and/or goals, please let us know; I, for one, would be very interested in hearing about them!

Ferrell

Anonymous said...

Thanks for answering my question Ferell.
And now we can see where our disagreements really lie, besides the ideological morass about NASA's failings and the role of private sector.

As I made clear, I believe a human payload can't make it back from Mars with current or foreseeable tech. You may believe differently but that's irrelevant: even if it was possible, it would be grossly wasteful. And that's an understatement. How much is the life of an astronaut worth, really?
The race to the Moon and back would be basically the same thing, except less wasteful on paper. In practice it would be more deletrious because it could actually be done so I would oppose such a prize lest it give people ideas.
The race to orbit and back would be even less of a waste but would add insult to injury by being the epitome of a rocket to nowhere. So much has already been wasted lifting bodies to a white elephant in LEO... enough already! I don't understand why you're all obsessed about doing something useless more efficiently. Useless is useless.

You've got to understand: there's no McGuffinite. There's nothing to bring back from Mars or anywhere else and therefore no reason to routinely send people to orbit and back. Enough has been wasted already in pursuit of unrealistic post-WWII dreams.

You ask what I would give a prize for.
The only promising transportation-related prize at this point would be some kind of solar sail prize I think.
But really I wouldn't want to give prizes for transportation because there's too much focus on that aera already.
You might give prizes for discoveries but I doubt it would be much of an incentives considering the likelyhood of discovering anything really interesting unless prospection can be done on the cheap (telescopes or possibly robotic solar sails).
So how about a prize for a robot that manages to extract a ressource (say H2O) from a type of small body or terrain and to process it to a specification?
You know, a prize for something that could actually be useful and trigger the developement of useful technologies. Or are you uninterested in this sort of prize?

-Horselover Fat

Anonymous said...

=Milo=



Ferrell:

"Another 'race' could be from Earth surface to orbit, back again, and then back to orbit; again, cost, time, reliability, and payload mass would count"

This is not even remotely race-worthy.

Taking 10 minutes or 4 hours to launch into orbit does not really make that much of a difference. Either is quite easy to fit into your schedule, even for space tourists. If you're actually going somewhere beyond Earth's orbit, then practically any launch duration is going to be a miniscule part of your total mission length anyway. Especially since gravity drag already makes overly dragged-out launches inefficient anyway.

Cost and reliability are far more important to optimize for than speed.

Refurbishment work is also not really that important to optimize for duration, since a month or so between launches would still be very good if you can do so cheaply. Again, cost is a much more important concern.

A race would only encourage people to design an overcharged vehicle that can't keep up its speed for long before it falls apart and/or you run out of money for further launches.

Damien Sullivan said...

Humans to and back from Mars orbit: dangers are radiation and zero-gee. Radiation can be dealt with via lots of shielding. This seems perfectly feasible on the tech side, just very expensive if you're launching it all from Earth. Sustained rotating gravity would take some engineering, and increase the size and shielding needs of the ship; has a good chance of being expensively doable, but we can't be as certain.

The most obvious prizes would be for being able to get to Earth orbit for less than $X/kg, with X decreasing one prize after another. If you think markets might do something with space if transportation were cheap enough, but no one will invest in transport research without a guaranteed market, you provide the guarantee. That or you fund the research directly yourself, but one can do both.

Instead of a cash prize, one might promise to purchase N launches at $X/kg, thus making the launch capacity available.

First X might be $1000. Still far too high to be revolutionary but 1/3 the price of the Russians.

I suspect the prize would wait quite a while. I'll believe SpaceX numbers when they've been operational longer.

Thucydides said...

Rotating ships to provide artificial gravity can be done relatively easily. Attaching a tether to the trans orbital injection stage and swinging the crew module on the other end only adds one small addition to the traditional method of rocket transport, and since the injection stage is "dead" there is no critical need to reel it in at the end of the mission; just cut the tether and let it fly off into space.

This also limits the need for shielding to to crew hab. This is still pretty heavy, but nowhere near the mass of some design proposals.

Getting to Mars and back has been extensively studied since the 1960's (or earlier, Das Marsprojekt is the conceptual foundation for most mission architectures up until Mars Direct in 1990), so most of the technical aspects have been identified. The only factor really missing is the will to actually carry out the project.

Tony said...

Human spaceflight to places like Mars is justified economically because humans are much more efficient than robots. 5 minutes for a man on Mars is equivalent to a whole day of rover activity remotely controlled from Earth, if Steve Squyres (principal investigator of Mars Exploration Rover program) is to be believed. It is morally justified because the science return is worth the risk to human life (maybe just barely, but still worth it). But dreams of colonization and space civilization is going to have to wait for the few centuries it's going to take (at least) for research expeditions and stations to grow into an industry that needs a civilization to service it.

Having said that, I'm not as pessimistic as some about being able to get humans to Mars and back in the next several decades. But it will have to be the manned spaceflight focus of some very rich government to do it properly and safely, for at least the next century or so, maybe longer.

Anonymous said...

China has the will and China can afford a manned mission to Mars. Obviously you don't develop somehting like that over a few years but, depending on how old you are, you'll live to see whether you were right about how feasible it is to lift bodies from Mars surface, accelerate them towards Earth and keep them alive... all with gear that needs to be lifted from our gravity well. I say China won't even try (not this century anyway).

Mars is the one place where humans presence is justified. It's not that humans are faster than rovers managed from Earth (they are of course but robots are so much cheaper to operate that they remain several orders of magnitude more efficient) but that they can do so much more with the right equipement! There is of course more to it than the objective work people could do there.

"Humans to and back from Mars orbit"
Now that's just perverse!
You want to get humans THAT close to walking on another planet and not do it? Not only that, you want to invest a ridiculous amount of resources on them NOT landing?
You'd need to launch into orbit all the fuel and supplies for a return voyage, the extra radiation shielding, the extra fuel to carry that shielding back to Earth, the extra tanks and stuff, still more extra fuel to get all that extra weight to Mars orbit and still more tanks for that... all that so that your astronauts can avoid landing on Mars and achieve NOTHING instead?
Have you learned nothing from Apollo? Doing something challenging won't automatically open the way for more!

-Horselover Fat

Geoffrey S H said...

"Now that's just perverse!
You want to get humans THAT close to walking on another planet and not do it? Not only that, you want to invest a ridiculous amount of resources on them NOT landing?
You'd need to launch into orbit all the fuel and supplies for a return voyage, the extra radiation shielding, the extra fuel to carry that shielding back to Earth, the extra tanks and stuff, still more extra fuel to get all that extra weight to Mars orbit and still more tanks for that... all that so that your astronauts can avoid landing on Mars and achieve NOTHING instead?
Have you learned nothing from Apollo? Doing something challenging won't automatically open the way for more!"



Cool it. Exclamation marks everywhere will not bring any more answers than a calmer post.

Damien Sullivan said...

I was responding to the prize for going to and from Mars orbit, and then the statement that that wasn't safely technically possible. I may have misunderstood the latter. Certainly getting a human back from Mars *surface* seems much harder, given the higher gravity than Luna where we were able to send a viable return rocket.

Tony said...

Horselover Fat:

"Now that's just perverse!
You want to get humans THAT close to walking on another planet and not do it?"


Demonstrating that humans can be projected across interplanetary distances and returned safely would in itself be an exceptional achievement. I'd certainly be willing to invest in doing it two or three times to make sure it could be done reliably.

Tony said...

Damien Sullivan:

"I was responding to the prize for going to and from Mars orbit, and then the statement that that wasn't safely technically possible. I may have misunderstood the latter. Certainly getting a human back from Mars *surface* seems much harder, given the higher gravity than Luna where we were able to send a viable return rocket."

The impulse for getting off the surface of Mars isn't all that much. ISTR it's about four times that to get off the Moon, for a given payload. That's manageable in a two piece lander.

Anonymous said...

It might be worthwhile to try a robotic version of that lander/launched first to see if it can be made to work reliably if the terrain turns out not to be ideal (guiding it precisely would require more rockets or at least more fuel I imagine) among other things but my uninformed opinion is that launching from Mars' surface, while very challenging, isn't even the biggest obstacle.
The big deal about a manned return trip from Mars seems to be that you'd need to use up A LOT more fuel (with all that it implies) than you'd otherwise need to in order to keep the journey's length reasonably short.
So the first thing to develop in view of a Mars return trip might be optimizing recycling and otherwise improving on the mass requirements of life support (including keeping the astronauts in decent health, psychologically and otherwise). It seems to me (uninformed speculation) that it would allow an optimization of fuel use which would make a Mars return trip much more practical (but more of an ordeal due to the length of the trip). Much of this work could be done on Earth without paying launch costs or risking lives. Maybe you could devise a prize for that?
Robots which can produce some of the supplies required for life support on Mars' surface might also improve on the mass requirements of a fuel-efficient return trip which would I understand imply a very, very long stay on Mars on top of the actual travel time.

Aside from how agitated it drives me to even contemplate people orbiting Mars aimlessly before returning to Earth, I really don't understand the argument for not landing.
Yes, it would be easier not to land and yes, it would be a useful test... if it was economical. But please explain to me what scenario would make such an approach less expensive than landing at once you consider the total cost of the campaign. The only such scenario I can see is precisely the one I would want to avoid at all costs: people are sent to Mars orbit but no subsequent mission lands.
If you're going to land at some point, try landing on the first run and you'll save one trip if get it right. If you botch the landing or the launch, a crew is dead either way. And if you botch the return trip, the radiation shielding or the life support (but not so badly that the crew doesn't reach Mars alive), a crew is dead or terminally ill but their lives would not have been thrown away for nothing.
It's not like the Moon: it's a long, long trip! Sending people all the way out there would be extraordinarily expensive and taxing for them as well, not to mention dangerous. Such a voyage shouldn't be pointless!
On the other hand, an unmanned test of every aspect of the mission you can test without a live payload should be much cheaper and could be worthwhile.

But the best argument for landing is of course that the astronauts' job is done once their work on the surface is finished. At that point their lives are obviously not worth even 1% of the cost of bringing them back, assuming you could even return them in good health.

-Horselover Fat

Tony said...

Landing on Mars is not an incidental or marginal expense. Nor does it involve only a marginal increase in risk. Yet from the capabilities point of view, it's just the next increment beyond getting a crew there and back safely. But adding that capability to the flight plan probably doubles the mission mass, meaning bigger or more Earth departure stages and bigger or more Mars orbit insertion stages. Or maybe it means prepositioning the lander in Mars orbit with a cargo flight (adding a Mars orbit rendezvous to the flight plan). Or maybe it means prepositioning the Earth return vehicle on the Martian surface, a la Mars Direct (adding a precision landing to the flight plan).

However you do it, it's a big step that should not be integrated into the flight plan until all the previous steps are demonstrated adequately. And the length of the mission actually has little bearing on how much you try to do on a mission. Interplanetary transit takes time, and involves big risk, that's true, but overloading on mission objectives that involve untested hardware* is even a bigger risk.

*Earth orbit and Lunar testing can only go so far. Ask Neil and Buzz how much they didn't know even after Apollo 9 did Earth orbit testing of the LM and Apollo 10 flew the whole mission profile minus actually going the final ten miles to the surface. The same will apply to manned Mars landing equipment -- until you actually take one down to the surface and back, it's not going to be fully tested.

Finally, let's not get to wrapped up in fears of Mars orbit being a dead end. It's an incremental step towards landing, not a non-destination. So what if it costs more money and takes more time? If the political commitment is there, Mars orbit will be just a stage in the process. If the long term commitment doesn't exist, a landing mission -- even a successful one -- will, in the final analysis, just be a stunt.

Anonymous said...

We seem to be talking about different things.
You're talking about the first mission while I'm talking about the whole campaign.
And you seem to be talking about a different sort of operation.

I see how you could have a stunt where you send people to die on Mars without having done much robotic groundwork, without much equipment to get work done and barely more supplies than they need to reach the place. If you're trying for a stunt, I figure that could be a good bit cheaper than a proper mission.
I also figure the cost of productive Moon mission would differ even more relative to a Moon stunt.
But you're talking about bringing people back from Mars. How much would you save relative to the mission cost by downscoping it to a stunt?
You say mission duration is irrelevant. Does that mean you are assuming a relatively low mass cost for extending life support way beyond the duration of a Moon trip? Or are you envisioning some kind of new propulsion technology that could make Mars a month-long trip or something?
Or maybe we have a different definition of "stunt". I'm not sure what you'd expect the follow-up on a successful mission to be.
The way I envisioned it, the length of the trip dominates the mission costs (either because of the duration or because you need a huge acceleration) and that factors in basically everything.
Which is to say I don't understand why landing and launching would double the mission mass either. I'm not envisionning landing with the deep-space life support "module" for instance, again a decision in part driven by the mission duration.
Maybe I'm missing something simple.

With regards to testing, what tests could you do safely on the lightweight Mars orbit trip that you couldn't do on Earth, on Earth orbit, without a live crew or, if that was the only way, in the course of a first complete mission?
I don't think there would be a rationale for a manned Apollo 10 today but I don't understand how Mars could be done with that approach anyway. Apollo could afford a ridiculous number of missions due in part to the short mission duration. Mars has different economics.

-Horselover Fat

Tony said...

Re: Horselover Fat

It's very simple -- a lander just about doubles Mars mission mass. That means more launches to put both the lander and extra propulsion resources in space. There's no point in doing that until you're sure the rest of the hardware works. That means you run one or two (or even three, if it takes that many time to get everything right) Mars orbit and return missions before you go with a landing. It's just like everything else done in space -- you build up capabilities carefully, incrementally.

And what I mean by "stunt" is doing something outside of a careful, incremental plan. An all-up mission first mission that included every capability, including a landing, even if it successfully returned the crew to Earth, would be a stunt. It would also be extremely dangerous and not very likely to succeed, because too much untested hardware would be sent on one mission.

WHich leads me to my point about mission duration not being a factor in deciding how big an advance to make with each mission. The figure of merit is added complexity, not duration. So what if you can only run one mission every 22 months, and that mission is very expensive? Mars is a long way away, and difficult to engage. You take a measured approach and put everything together over time, making sure each new capability is demonstrated and well understood before moving on. You don't just go for the landing on the first mission because it costs less money to do so.

Tony said...

"one mission every 22 months" should read: "one mission every 26 months"

Rick said...

I guess I should write a front page post about going to Mars.

And thanks to everyone for keeping some strong emotions pretty much in check.

It is a valid and interesting point that the complexity and cost of robotic missions tends to go up as the low hanging fruit gets picked. After all, the first mission to a given planet can produce spectacular results just by taking a few snapshots. Filling in the picture takes more work = more money.

Anonymous said...

I don't understand what problem you have with emotions.

I think the life support problem needs to be addressed explicitely, Rick. Did you address it in another blog entry? Unless I'm missing something, it hasn't been solved and so you can't plan manned missions like you would plan robotic missions or even manned missions to the Moon. Not with proven and scalable propulsion technologies, that is.

The robotic campaign is being carried out in the fashion you're suggesting, Tony. And that's reasonable.
But as far as I can see, you're ignoring the problem with manned spaceflight entierly and therefore proposing something which I fear would turn out to be impossible to fund over the long haul, even by the most prosperous dictatorship on the planet.

If you're unwilling to explain the nature of the pre-landing tests you're talking about (which would somehow require no lander but live bodies in Mars orbit instead) or why you seem to be assuming free life support, perhaps you could volunteer an order of magnitude for the total cost and duration of the stunt-less but ultimately successful campaign you're envisioning.

-Horselover Fat

Anonymous said...

Horselover Fat said:" think the life support problem needs to be addressed explicitely, Rick. Did you address it in another blog entry? Unless I'm missing something, it hasn't been solved and so you can't plan manned missions like you would plan robotic missions or even manned missions to the Moon. Not with proven and scalable propulsion technologies, that is."

Let me say something on this subject: life support research has been progressing for decades; everything from hydroponics to bio-reactors have been proposed and tested, with varied amounts of success for long term sustainability. As far as radiation protection goes, physical shielding may be augmented with magnetic fields, if a British study is anything to go on. As far as I can tell, the life support tech is at the point where a long term (a month or more) space mission would do much to advance the state of the art.

Ferrell

Tony said...

Re: Horselover Fat

You're really overcomplicating the discussion here. Exploration missions are taken incrementally in series so that you don't depend on too much untested hardware or too many untested procedures on any given mission. It's as simple as that. For Mars, I would suggest the following set of mission types:

A: 2-year flyby on a free return trajectory. This demonstrates both human and life support system endurance over interplanetary distances.

B: Full duration mission with a Mars orbit insertion. This demonstrates a Mars orbit insertion and Earth transfer orbit insertion. It also extends the life support technology to a full mission duration.

C: Same as the B mission plus a landing. THis demonstrates a landing and return to orbit capability.

Just like with Apollo, the rule is that one type of mission has to be successfully completed before attempting the next. If a B type mission has too many problems -- even if it successfully returns the crew -- at the next opportunity another B type mission is attempted. If every mission is completed satisfactorily, then the third mission will be a landing mission.

Note that the A class mission is a minimal mass mission, because one only has to throw a hab and an Earth return vehicle into an interplanetary orbit. The B class mission requires a little more interplanetary mass, because you need a Mars arrival stage and a Mars departure stage. The C class mission requires even more propulsion, in order to throw the lander and stop it in Mars orbit. So each mission only requires the propulsion necessary to accomplish its objectives, meaning you only get into megaships or multiple flights at the end, when you take the lander along.

As far as life support is concerned, between ISS and Mir we've got literally years of experience in life support management and consumption rates. We know plenty about how many consumables to send along for X number of months. With Mars one doesn't have the luxury of resupply flights, so of course you have to send all consumables along. But that's entirely doable. It's no big mystery.

Anonymous said...

Without incremental targets worth achieving and with no realistic final target, incrementalism has turned into a dreadfully inefficient welfare program (not for astronauts of course: they get killed).
So yeah, I'm skeptical.

Yes, life support is technically doable. The problem is that the cost would be outrageous with current technology and practices and there is little benefit.
The ISS level of life support is also inadequate if you don't want people to die.
How do you double mission mass by including a lander if you assume an ISS type of life support anyway?

Your mission plans belie your principles. You are making people depend on untested stuff for no good reason.
The one thing you need live bodies to test is life support and you're proposing to do it in the most dangerous way possible: by putting people where they can't abort and they can't get help.
Orbital transfer tests can meanwhile be done without a crew, carrying supplies and maybe the lander prototype to Mars orbit.

It seems you're willing to spend extra and to increase the health risks as long as resources are spent on manned spaceflight, as if it was the end and not the means.
If you genuinely want to avoid deaths, minimize the health risks. Don't just waste inordinate amounts of resources on rockets so that astronauts have a chance to come back.
Potentially getting people killed as part of a string of demonstrations but refusing them the opporunity to achieve something by comitting to a riskier mission (or even a suicide mission) makes no sense to me and will not get you the right volunteers.
I guess that's the kind of thing politicians and generals would force on the mission. Maybe it's for the best that there's no manned space program at this stage. Robots can be managed rationally.

Life support can be in large part developed and tested on Earth, Ferrell. Some of it would actually be worthwhile work outside of the space context.
Once you get that part right, you can do a cheaper test in orbit or at an L point and the test can last a lot longer than a month (unless it's aborted) to make the expense worthwhile.

-Horselover Fat

Tony said...

Re: Horselover Fat

Simplistically, Progress M cargo flights deliver about 12 tons a year of consumables to the ISS. So for a two year mission with three or four crew, figure around 25 tons of consumables. Figure somewhere in the neighborhood of 35-40 tons of consumables for a full duration mission. That's a lot, but it's not unmanageable. And the actual mass of consumables would probably be less, because a Mars transit hab would have a lot smaller internal volume than the ISS to fill up with atmosphere gas, which is a big part of your consumables.

A lander would double your mission mass because it has to land on and launch from the surface of Mars, meaning it needs a lot more propellant and tankage than the Apollo LM. It also should cary a surface stay capability for a month or two, because the time from Mars arrival to Mars departure is going to be in that neighborhood.

WRT mission design, you seem to be all over the place. You keep going on about expense and risk, but you reject lower cost, lower risk precursor missions prior to a landing attempt. Please, take a deep breath, reread what I have said, and give it some thought before responding.

Rick said...

My problem with 'emotions' is when they tip over into flaming. For a long time the comments here were almost uniquely pleasant to read, by internet standards. More recently there's been occasional snarling that detracts a lot from the reading experience.

I did one full post on life support, way back: Spaceship Design 102: Life Support.

But more to the immediate point, as I've noted a couple of times: The ISS, and Mir before it, are best seen as interplanetary training missions, specifically testing life support, and living and working in space.

The results are pretty positive - the ISS has operated for more than a decade without any emergency that would have endangered the crew if they were in Mars orbit instead of Earth orbit. By the time we actually send a human mission to Mars we will likely have at least a generation of similar experience.

Tony said...

Re: Rick

I think the life support question for a lot of people boils down to the perceived inefficiency of just adding up the consumables mass and sending that much stuff, plus a contingency amount, along for the ride. There's a strong faction that wants more recycling and onboard food production. They think that will reduce mass and make the mission more doable. Of course, it is by no means established that all of the recycling equipment and a gardening environment would mass any less than bulk supplies, especially when necessary redundancies are considered. Also, it would add all sorts of complexity that could endanger the crew, especially if any single points of failure were accepted in the design.

Rick said...

I tend to agree. I doubt that a self-contained ecohab would save substantial mass over stored supplies until duration is in years, quite apart from the fact that we don't know how to do it yet.

At some point in the 'plausible midfuture' we will probably develop this technology, but not in the early interplanetary era.

Anonymous said...

I'd say an 'ecohab' would be a good addition to a Mars mission; it would give the crew someplace for some down-time, give some redundency to the 'sandard' life support system, give the crew a break from rations every once-in-a-while, and if part of the support (unmanned) lander would help to expand the Mars ground base.

Ferrell

Anonymous said...

Oops, that should read 'standard' life support system.

Ferrell

Anonymous said...

=Milo=



Rick:

"I doubt that a self-contained ecohab would save substantial mass over stored supplies until duration is in years, quite apart from the fact that we don't know how to do it yet."

Yeah, I see that as something you'd do in a planetside dome or maybe a space station, not a ship.



Ferrell:

"give the crew a break from rations every once-in-a-while,"

I don't think so. Farming is easier if you have a monoculture, or at least only a few types of (easily-kept) plants to worry about. It's easier to have a large variety of foods if they're prepackaged.

Anonymous said...

Milo, I don't know about you, but every once in a while I like fresh veggies; prepackaged food (no matter how much 'variety'), gets old after a while. A tangerine, tomato, cucumber, or even a radish or two would go far in bolstering my morale during a multi-month interplanetary voyage.

Ferrell

Damien Sullivan said...

Well, there's what's nice to have, and there's what you can afford, or convince people to pay for. An ecohab would probably add a lot to the mass of the ship, though I guess there's a range: fully redundant biological oxygen and food recycling would at a wild guess at least double things, while a little additional module could allow for psychological greenery, herbs, and the occasional high-productivity vegetable.

Of course, there's what a multi-month ship would look like. Slightly bigger than Apollo, or something more like Mir or ISS being pushed between orbits?

Rick said...

That is a good question, and IMHO largely a matter of human factors.

Thucydides said...

If you want all the amenities, then you are indeed looking at an ISS sized spacecraft (800+ tons), with al that implies.

If you prune away all the excess, you could probably get to Mars on an Apollo+ sized rig, although the astronauts might not be in very good shape by the time they got to their destination. I am pretty sure the 1960's Boeing proposals built around a three stage NERVA had something like that in mind.

Since mass is the limiting factor, the first expeditions will probably go with some form of MRE. Later, semi recycling might e seen as appropriate, I'm sure that reclaiming 50-80% of the water or air used is probably quite doable without breaking the mass budget and lowering some of your consumables to carry.

The other tradeoff will be how fast you want to get there; a VASMIR powered ship that can reach Mars in 39 days will have a disproportionate amount of mass devoted to the electrical system, limiting the ability to carry a greenhouse "(as well as the need). If you want a garden, then a permanent structure like the ISS or an Earth Mars Cycler would be the best place for one.