Riding to Mars in a capsule?

spacefire · Dec 5, 2005

Without ISRU you are left with flag and footprints missions unless you go for simply colossal spacecraft or fleets of spacecraft. With ISRU you can do significant science and exploration for compartively modest masses. with everybody now touting budgetary constraints to justify the modest-primitive CEV, I can't believe nobody sees the need to get the public-and thus their congressen-excited by the prospect of going to Mars. The public animal has a very short attention span. Thus there will have to be something exciting-which is putting a man on Mars- pretty early in the program before funds dry up

There won't be time and money to send much ISRU hardware AHEAD of the manned expedition and make sure it works. <div class="Discussion_UserSignature"> http://asteroid-invasion.blogspot.comhttp://www.solvengineer.com/asteroid-invasion.html </div>

radarredux · Dec 5, 2005

> The public animal has a very short attention span./i> Zubrin and others have made the same point, and that is why Zubrin thinks a Mars mission should essentially fit inside the time of a single President, 8-years (assuming re-election). But Zubrin's plan assumes an HLV <img src="/images/icons/smile.gif" />. Once NASA has a relatively efficient HLV in place, it can probably do a large range of projects within a short period of time. For example, a rough equivalent to the ISS could probably be launched, fitted out, and operational within 2-4 launches (1-2 years of launches). Likewise, a significant Lunar habitat could be assembled in a similar time. A Mars (semi) Direct approach could be launched relatively quickly -- the biggest issue there is planet alignment and having all your systems ready to go during the narrow window of opportunity. In short, with an HLV operational, just about anything is possible between LEO and Mars within a single president's time.

mattblack · Dec 5, 2005

Yes, the SDHLV has a 7m fairing. My mistake!! My 5m figure came from the Delta IV, Atlas V and the CLV. Although, 5m is wider than the Shuttle Cargo Bay, of course. <div class="Discussion_UserSignature"> One Percent of Federal Funding For Space: America CAN Afford it!! LEO is a Prison -- It's time for a JAILBREAK!! </div>

JonClarke · Dec 5, 2005

I wonder why 7 m was chosen? It is actually are rather awkward size for crwed mission elements, somewhat narrow for tuna cans and too fat for longitudinal layouts. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

JonClarke · Dec 5, 2005

if you want a minimalist Mars mission then you can't get past the flyby lander architectures. With a two person crew you could to with essentially one SDLV launch. High mission and crew risk though. I disagree about he public attention span. If the public is prepared to accept space progams with 15 year development times, and there is every sign they do, they will accept the time to develop ISRU Mars mission. The time to do space missions on a tide of public emotion is well past. Remember that ISRU relies on simple technology proven on an industrial scale on earth - the Sabatier reaction, the Fischer-Tropsch reaction, CO2 electrolysis, H2O electrolysis, pressure condensation of gases, and the reverse water gas shift. Bench top scale tests for mars application of these have all been run, at least one (CO2 electrolysis) was developed to a Mars qualified test bed. It was supposed to fly in 2001, but did not when that lander was cancelled. I repeat, ISRU as a core mission requirement is essential if you want to humans to explore Mars. It is essential if you want to do it safely, it is essential if you want to do it for the lowest cost, and it is essential if you want to do it sustainably. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

j05h · Dec 5, 2005

Jon's right on this. If you want to have any sortie capability, long-term/permanent basing or a mission mass under several thousand tons, ISRU is a necessary technology. It is, as he pointed to, a fairly common set of reactions, they just need to be packaged properly. Josh <div class="Discussion_UserSignature"> <div align="center">We need a first generation of pioneers. </div> </div>

subzero788 · Dec 5, 2005

Can someone explain how is NASA going to afford to keep up lunar missions while paying for the enormous cost of constructing a lunar base and an extended human presence on the moon (even with the help of international partners which isn't definite) AND at the same time develope the new architecture and technology required for a Mars mission? NASA is having trouble at the moment paying for developing the CEV while operating the shuttle and ISS, so how are they ever going to be able to fund a mars mission when they are paying for the enormous costs of keeping a moon base and perhaps the ISS (or its successor) at the same time? Sorry if I sound a little pessimistic but I just don't see NASA being able to afford a Mars mission, especially since any international help will probably be concentrated on funding and/or constructing a moon base. It's kind of like the situation at the moment, where the development of the ISS and the running of the shuttle reduce NASA's ability to get to the moon, I think the same thing will happen on the moon with moon activities restricting funds for mars. Money, money , money. What do people think?

Swampcat · Dec 5, 2005

"Can someone explain how is NASA going to afford to keep up lunar missions while paying for the enormous cost of constructing a lunar base and an extended human presence on the moon..." This is a good question, one that Dr. Griffin has addressed. He has said, in effect, that the only way all of this stuff is going to happen is with the help of private enterprise. Exactly, how that will play out is not clear at this point, but check out the spaceref.com article NASA and the Business of Space. <div class="Discussion_UserSignature"> ------------------------------------------------------------------- "I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical. Unsuccessful rebellions, indeed, generally establish the encroachments on the rights of the people which have produced them. An observation of this truth should render honest republican governors so mild in their punishment of rebellions as not to discourage them too much. It is a medicine necessary for the sound health of government."Thomas Jefferson </div>

gunsandrockets · Dec 5, 2005

" ISRU is a necessary technology. " Which means there is no escaping the neccessity of nuclear reactors for manned deep space exploration; whether as electrical power sources for ISRU or as a thermal power source for nuclear thermal rockets.

gunsandrockets · Dec 5, 2005

"But Zubrin's plan assumes an HLV . Once NASA has a relatively efficient HLV in place, it can probably do a large range of projects within a short period of time. For example, a rough equivalent to the ISS could probably be launched, fitted out, and operational within 2-4 launches" New technology might allow us to build large habitats with less mass than in the past. A good example is the Bigelow Nautilus Habitat. Supposedly the Nautilus will have a similar living volume to the old Skylab, yet mass only 1/4 as much. It took the launch capacity of a Saturn V rocket to loft Skylab to orbit wheras the Nautilus will only need a Proton rocket.

mattblack · Dec 6, 2005

8 meters!! Better yet. Thanks, shuttle_guy! <div class="Discussion_UserSignature"> One Percent of Federal Funding For Space: America CAN Afford it!! LEO is a Prison -- It's time for a JAILBREAK!! </div>

subzero788 · Dec 6, 2005

Thanks for pointing out that article, swampcat, it made some interesting reading! Commercial participation does appear a little bit iffy at the moment but it does seem to be crucial to NASA overcoming some of its funding problems. I guess we'll just have to cross our fingers and wait and see...

JonClarke · Dec 6, 2005

First of all the development of any Mars mission will be well down the track, probably after 2020. Secondly much of the basic hardware development will have been carried out under the the auspices of the CEV and lunar program. Third, because of sequential timing the costs peaks will not happen at the same time, keeping things (hopefully) within budget. Sp this is all a long way down the track, giving us the leisure to discuss various options. <img src="/images/icons/smile.gif" /> Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

bobw · Dec 6, 2005

Money, money , money. What do people think? When the space program first started, it was a bugetary anomaly for the program. The only way not to have one project "compete" with another is to have only one project at a time. I would rather have the moon mission ready to go when the shuttle retires than to have them pull out a blank sheet of paper then. If we stop ISS/Shuttle for the Moon where does it end? Stop the Moon for Mars, Mars for some asteroid, the asteroid for Phobos? There will always be a greener pasture but I think we should finish what we start. The only reason something else didn't slow down Apollo's development is that there was nothing else. That situation is a statistical outlier in space program financing, not a goal to be attained. <div class="Discussion_UserSignature"> </div>

radarredux · Dec 6, 2005

> how is NASA going to afford to keep up lunar missions while paying for the enormous cost of constructing a lunar base and an extended human presence on the moon (even with the help of international partners which isn't definite) AND at the same time develope the new architecture and technology required for a Mars mission? That is a good question, and one we can only speculate about today (~15 years before serious efforts for Mars gets underway). Here are some discussion points: <ol> <li> "enormous cost of constructing a lunar base" -- there is no strong commitment or plans to building a Lunar base right now. The ESAS, which carries us to about 2018, is designed to deliver the capability for relatively small sorties. The choice of funding a Lunar base will be left to future Presidents and Congresses. <li> "enormous cost of constructing a lunar base" -- Should a future Lunar base be constructed, its cost may not be enormous. A benefit of the HLV and ESAS architecture is that a huge amount of mass (much more than Apollo) can be delivered to the Lunar surface in a single flight, so unlike ISS, dozens of flights will not be needed. Cover the inflatable habitat with some regolith, and you have a additional insulation and protection from radiation and micrometeorites. <li>As you mentioned, international partners may be major players, and this is one of the reasons Griffin wants to complete ISS -- to keep them happy. <li>Much of the technology for the Mars mission is being developed as part of ESAS (e.g., the Methane engine and HLV). And of course much of the life support systems for ISS and ESAS can probably be reused for Mars. Zubrin's plan, one of the more fleshed out plans for Mars, includes very little new technology development. <li>The NASA of 2018 may be more efficient. Griffin has said the cost to launch missions must be brought down, and part of the ESAS goal is to use mature technologies so that we h</li></li></li></li></li></ol>

radarredux · Dec 6, 2005

> fford to keep up lunar missions while paying for the enormous cost of constructing a lunar base and an extended human presence on the moon/i> Here is part of Griffin's answer from a recent (and pretty good) interview (the added emphasis is mine): An interview with NASA Administrator Mike Griffin http://www.spaceflightnow.com/news/n0512/05griffin/ <blockquote>In reply to:<hr />Now the second point is, the architecture we released is a transportation architecture, it's howdo we get to the moon. Now pardon me for behaving like an engineer, sorry, but I happen to think that's the first step. Step two is, what do you do when you get to the moon? What we've done is to craft a system which can drop 21 metric tons of dry weight, net payload on the moon with every flight. And it can drop more on the moon if you use it in an unmanned mode as a one-way autonomous mission. Now that allows you the components to build a research station on the moon, a lunar base if you choose to use those words, it allows you the components to build that base, that research station - or not - as the nation would choose to do at that time So what we've done is to put in place an architecture which can allow you to have as much or as little lunar base as the nation wants to a decade or a decade and a half from now So what we've done is offered a program where a lunar base can be built by the yard if people want, but does not cause you to have to buy into some, you know, non exit ramp program right from the start. OK? That's what I would like people to focus on. But at the end of the day, this system can drop 21 tons of dry weight, landed payload on the moon every time it flies. ... And the lunar la</blockquote>

josh_simonson · Dec 6, 2005

If, by the time the moon landings are occuring, private suppliers can orbit fuel and supplies for less than NASA's in-house options (which isn't very difficult) then NASA will buy those services rather than use expensive government vehicles. They hope to lower their launch costs by a considerable amount in this way, which will allow them to focus more funding beyond LEO.

JonClarke · Dec 6, 2005

You don't need NTR or nuclear powered ISRU to go to Mars. It is not the panacea for power requirements often suggested. You can design a perfectly adequate ISRU plant to supply a four person, 600 day mission with 14 tonnes of LOX-methane for an ascent stage, over 2 tonnes of CO-O2 propellant for a rover, 0.5 tonnes of O2 and over 7 tonnes of water for the crew, using 20 kW. This would require a 550 m2 sized flat solar array on Mars, with a 25% margin, deployable as a mat from a roll by a small rover. These would mass, using conservative estimates, 2.2, with another 0.5 tonnes for batteries. State of the art reactors for the same amount of power would mass about 4 tonnes, and would need to be deployed at least a km away, requiring complex handling and deployment systems. Compared with a reactor a solar array is simpler, much more reliable and much more mature technology. NTR may more trouble than its worth, given the unresolved safety and security issues. Accidents with NTR cores during development in the 60's resulted in ejection of burning core fragments. Boil off of highly volatile fission products and contamination of the exhaust is an unresolved and possibly unresolvable issue, as is containment during an accident. Requirements for safe disposal in high earth or solar orbit, extensive cooling systems and shielding eat significantly into the theoretical advantages of NTR performance. Like compact power reactors, NTRs need highly enriched fuel, raising major security issues in the event of an accident. The huge development costs of NTR are also prohibitive, expertise and infrastructure is now largely non existent and would have to be developed from scratch. Chemical propellants by comparison are quite adequate and again, much more mature, and safer. Please note that I am not saying that there is no place for nuclear power in stage. RTGs are already essential for outer solar system missions, and NEP will similarly be essentia <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

JonClarke · Dec 6, 2005

I would really like to see what the mass break down is for Nautilus, i.e. what you actually get for that mass (supposedly 23 tonnes) and volume. Bigelow have been very cagey in what I have been seen about their detailed plans. Skylab's 77 tonnes included a 11 tonne solar telescope complex, consumables, earth imaging cameras, and extensive medical suite, a range of other experiments ample power, and a trash holding tank. As I recall the experience with Transhab suggests that by the time the inflatable is fitted out there is very little to choose between it and a rigid in terms of mass and volume, it does require much more work. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

najab · Dec 6, 2005

>As I recall the experience with Transhab suggests that by the time the inflatable is fitted out there is very little to choose between it and a rigid in terms of mass and volume, it does require much more work.Really? I thought it didn't save you anything in terms of mass, since the flexible materials were just as dense or denser than rigid materials, but that you did get more volume for your mass.

JonClarke · Dec 6, 2005

That's what I was trying to stay <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

radarredux · Dec 6, 2005

> If ... private suppliers can orbit fuel and supplies for less than NASA's in-house options (which isn't very difficult) then NASA will buy those services rather than use expensive government vehicles./i> That is the goal, but here is my fear: Suppose NASA (or one of its close contractors) provides a service for $1 million, and a company comes along that offers the same service at $500K. If NASA switches to the new company, in order to achieve the cost savings the people under the previous contract will be laid off. Will NASA have the guts to (or will the politicians let them) lay off the people on the original contract?

subzero788 · Dec 7, 2005

You make some good points, radar, perhaps you are just a little optimistic! I realise there is no plan at the moment to build a lunar base but I think its inevitable that we construct and operate one, especially before we go to mars. I was interested to hear that the new LSAM can get 21 tons to the Moon's surface, this will should make it easier to construct a base. I've been looking at the mass of several ISS components eg. 20t for Zverda, 14.5t for Destiny etc. so it looks quite possible as you said to establish a lunar base with just a handful of flights. Still, this doesn't mean that a base will come cheap. Does anyone know (roughly) what one of the new lunar missions will cost? I was thinking about 1 billion US in today's money but please correct me if I'm wrong. Even so, this seems pretty cheap compared to a shuttle flight that only gets us to LEO. I was thinking before that a moon base would cost a hell of a lot more to construct than the ISS, but now I'm not so sure. How much more or less do you think a basic moon base *could* cost compared to the ISS? I know this is very hypothetical but I'd like to hear other people's opinions anyway.

gunsandrockets · Dec 7, 2005

"NTR may more trouble than its worth, ... The huge development costs of NTR are also prohibitive, ... Chemical propellants by comparison are quite adequate and again, much more mature, and safer. " Maybe. If NTR is tried again they are not going to use a big rocket like the 75,000 lbs/thrust NERVA. Instead they are going to develop a small 15,000 lbs/thrust class rocket. And chemical rockets aren't cheap to develop either. The huge 250 tonne Earth Departure Stage has something like a 2 billion dollar development budget. And that doesn't even count the 10 billion dollar development budget for the Heavy Lift Vehicle needed to loft that monster stage.

gunsandrockets · Dec 7, 2005

"Skylab's 77 tonnes included a 11 tonne solar telescope complex, consumables, earth imaging cameras, and extensive medical suite, a range of other experiments ample power, and a trash holding tank. " Even stripped of equipment and consumables, do you think the Skylab massed less than 23 tonnes? Even a dry Saturn V third stage massed more than 20 tonnes, I believe. Bigelow may be blowing smoke when it comes to his Nautilus habitat, or maybe not. It's in his own economic interest to build his proposed habitat within the launch capacity of the Proton, and not require elaborate orbital outfitting and stocking before use.

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