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Posts Tagged ‘NASA’

From Hobbyspace, highlighted by Transterrestrial Musings:

The program of record (i.e. Ares I/V/Orion/Altair), which exceeds the expected budget substantially, will no longer be in the options table but kept separately just as a reference.

Yes!

The historic words have been spoken. Now for a better future for NASA, for spacefaring and for humanity.

The Augustine panel has been good beyond my wildest imaginations. (My imagination is extremely pessimistic.)

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Jeff Greason is a rational person who simply gets it. It is mind boggling how completely opposite from someone like Mike Griffin he is.

See Jeff’s presentation with the Augustine Panel.

Paraphrasing, “we could go to Mars with Ares V but we shouldn’t – cause we couldn’t stay anyway”. Exactly. That’s the problem with NASA. (or the major one)

I bet he will be ignored completely.

Also, I would like to work for that guy. Too bad because of ITAR I couldn’t work in the USA.

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There are a lot of implicit assumptions that heavy lifters of this or that throw weight must be used for future exploration beyond low Earth orbit.

These “needs” have never been logically derived from anything.

Yet space policy and exploration architectures must be based on rationality above all. There is no excuse whatsoever to do things on a whim. Hundreds of billions of dollars, and the future of humanity’s spacefaring are at stake.

There is no foreseeable need to launch over 25 tonne monolithic payloads to low Earth orbit in lunar exploration, and probably even that number could be seriously diminished with some more thorough planning. Orion, EDS, LSAM, all are below that weight, if they are refueled using a depot in space.

If the huge development and operational estimated costs for a heavy lifter rocket go away, then that money is freed for real exploration work. In-space hardware development, more launches, more missions and operations.

Flight rate is _the_ most important way of reducing launch costs, the single largest impediment for advancement of spacefaring, and the propellant depot enables a higher launch rate. Multi-launch scenarios with a propellant depot also enable competition, redundancy and flexibility, all very good things, ensuring safety, robustness and progress.

I repeat as a summary how

1) Solutions for space exploration, like any large endeavour, must be rationally justified. No baseless assumptions should remain.

2) The need of heavy lift is a baseless assumption. It can be one of the alternative ways of execution, but it can not be a starting point or an axiom.

3) The current architecture is heavily based on the implicit assumption of heavy lift. Hence a rational space exploration architecture would examine things from the ground up. It could end up with some radically different conclusions.

4) Propellant depots is one alternative way of executing space exploration beyond LEO, and it does not need heavy lift.

5) Propellant depots can, if executed correctly, increase launch rates many fold, and thus enable lower costs, progress, reliability, redundancy, robustness – all the things that the space shuttle promised but failed to do because it was a sole solution that could not sustain a high enough launch rate and was too costly.

6) NASA at the same time should keep on working with fundamental research, to enable continuous progress trends in space technology.

7) Space exploration should look as different from Apollo as possible – there should continuity and continuous improvement possibilities, robustness and progress. The architecture should be affordable as well.

8) New space technology, like cheaper launchers, should be demonstrated at a smaller, humble scale first. That way many things can be tried and progress is faster, for the same price and effort. One failure also will not be as critical.

9) There seem to be impediments for information flow inside NASA, and many professionally acknowledged things like propellant depots, EML2 rendezvous or space tethers are never even mentioned in NASA high level planning. This is not rational.

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Experts on the Internet

A lot of internet discussion is ignorant speculation, rumor spreading, ranting and flaming. But that’s not all. The freedom and self-organizing nature of enables massive diversity. Newsgroups, mailing lists, IRC, forums, Twitter – and sometimes there’s something there.

Michael Tobis comments on his experience of reading about the Iranian riots on Twitter – way before anything was said in the printing press. Being his usual self, it acts as a motivation for a longer article about the resignation of reporting on important issues (global warming changing earth significantly being Michael’s issue because of his expertise in that).

I’ve long been saying related things  in relation to space issues.  Now, the traditional media defends its views and sheepish forwarding of NASA public facade material as the right way. Maybe some examples are necessary. The aerospace developments of national agencies are full of failures. All ventures have failures. It’s just that aerospace has so few successes – especially rocketry.

What if Nasaspaceflight.com had existed during X-33? NASP is moot here since it was a secretive military project – hence no insight possible there.

Would X-33:s failures and their reasons have been predicted much earlier? Ares I and V had their critics from before day one. Technical critics. Budgetary. Industrial ones.

What is important and makes things different from mere ranting, or “armchair generals”, is that the NASA and ULA engineers provide, on their free time, insight into engineering matters. Instead of the public affairs that the rest of the media reports on. They have a passion for what they do and want to succeed and advance. If they see hopeless technical incompetence at the top level, they will voice their objections – it is practically their duty as citizens.

X-33 – Marching Towards Certain Failure

X-33:s first failure was trying to use very unproven technology (composite multi-lobed cryogenic tanks) in a billion dollar magnitude program. The technology could have easily been proven on a much smaller scale, very cheaply and fast, before starting the whole X-33 project. Competent engineers should have seen that one as a real high risk with easy reduction possibilities. You don’t risk billions just for fun, if you can easily avoid it! You risk it for politics though.

x33_tanksampletests

The table above is from NASA’s tank report (pdf in references), with tests done on tank samples done after the failure, revealing the gross inadequacy of the material for the intended purpose

If, on the other hand, the composite tank was seen as a high risk but not necessary technology for reaching X-33:s goals, then X-33 should have proceeded with the metal tank. In other words, if the composite tank was an optional “nice to have” component. But NASA:s Ivan Bekey testified otherwise – that X-33 had no use without the carbon fiber tank.

All around the X-33 seemed quite big and hugely ambitious on multiple fronts for an experimental vehicle anyway. What were the other objectives besides composite tanks? Could they have been tested in a faster and less expensive vehicle? The metal TPS comes to mind as one. Did it have even the inadequate bench background of the tank? There were military programs from the fifties to the eighties that had developed such things in labs – maybe there was something there.

What about the lifting body shape? The successing Venturestar kept changing shape constantly in simulations and grew big wings. It could very well be that Lockheed Martin and NASA simply didn’t know what they were doing, on any level really, and should not have started building X-33 in the first place. The knowledge base was not at the level to justify going that far yet. The close to existing J-2 derived aerospike engine was perhaps the biggest justification for the size and shape of X-33. But the potential reward of finally getting an aerospike engine flight tested just made the fall that much heavier – the large vehicle necessitated by this turned out to be unworkable. A failure on a lesser scale would not have been as hard. Close to ten years later, no aerospike has yet flown. There have been spike nozzles in hybrids and solids but no aerospikes, where the physical spike is cut off and replaced by a gas jet.

What should have been done to enable the X-33 building?

  • Bench tests of composite tanks (basic, room temp, progressing to multi-lobe, cryogenic). Test cryopumping as well (this has been done somewhat since).
  • Possibly aerodynamic tests with a much smaller vehicle (or generations) as a glider, first released from a helicopter, then an airplane and finally with a sounding rocket. Alternatively with conventional engines. Possibly horizontal takeoff to reduce test costs.
  • Aerospike engine small scale tests. Perhaps contract a smaller company for that, like Armadillo and XCOR have done tests cheaply for NASA methane engines.

If any of these solutions proved unfeasible, then no reason to build the Lockeed style X-33.

The Competitors

Rockwell had a shuttle shaped cylindrical tank vehicle with wings, which seemed pretty simple on the outside. McD had the DC-X growth model. At least both had some heritage in working hardware. There is very little engineering information available about the competitors so if anyone wants to help, drop me a note. Would they have succeeded?

Probably both would have failed as well, in the role of traditional X vehicles of developing new capabilities, mainly because of being too large. Both of the other potential X-33:s would have had a composite hydrogen tank as well (though possibly axisymmetric, even conical or cylindrical), so they could have had similar failure possibilities, though perhaps they would have had a different (sensible) development approach. As is evident from lab tests in the references, cryogenics and composites are hard to fit together.

The Shuttle thermal protection system  is notoriously work intensive, and as far as I know, the Rockwell proposal had quite similar tiles in its proposal. On the other hand, surface loading could have been less since the vehicle had its own tanks and high mass ratio. Also the SSME:s are very work intensive when reused. It was partly more of a rehash of existing technologies, which would perhaps have had moderate chance of success. If it worked, maybe one could try different technologies in it, if it was cheap to fly and could do incremental envelope expansion, while still having high enough performance to really stress test things like TPS or vacuum test less maintenance intensive engines. Heat loads on the composite structure would have been an interesting problem area as well.

McD’s precursor for their X-33 design, the small flying DC-XA program was cut prematurely (after having survived agency changes and funding problems) after a crash from a trivial easily avoidable failure, an unsecured hose. It could have made sense to do DC-XA again, to try the high speed properties, flying at different angles of attack and test the turnaround maneuver that it should perform after re-entry for landing. It would also have made sense to keep in the DC-XA scale and try lots of other solutions in the same vehicle (or fleet). It’s cheaper to test when at small scale. Only when the low capabilities of the vehicle would have been exhausted and good enough solutions found, would it have made sense to move to a bigger vehicle.

Conclusions

All  in all, space is no different from other fields, that rationality is the most effective way to reach sustained progress. It is obvious to any engineer worth their salt that one should retire as much risk as possible, as cheaply and as fast as possible before moving to the big bucks and long development time game.

Sadly, aerospace seems like a hopelessly irrational field in this regard. There are historical reasons for that attitude. Crash programs like Apollo or military ones have left their mark too deep – the field is unable to grow to a rational mature one. It is evident when looking at NASA’s troubled history with manned spaceflight. Since Mercury, Gemini and Apollo, it has not been able to build much incremental progress. STS was a partial success in capability – but it has stifled progress. Everything must always be started over, and at giant scale – making the unavoidable multiple tries very costly, both in time and money, and even utterly shameful in case of failures. A gigaprogram with failure as no option is a recipe, not for sustained progress, but for either a great disaster, or stagnation. A gigaprogram with failure inevitable is waste incredible.

So, the media of today should examine the world in such a perspective. Simplistic “against NASA / for NASA” analysis serves no one. There have been such incredibly farces lately that I’ve had to double check I wasn’t reading the Onion.

I speak for many, when I say, we don’t want delusional Programs, we want rational Progress!

Some sources:

1 Final Report of the X-33 Liquid Hydrogen Tank Test Investigation Team, NASA Marshall

2 Cryopumping in Cryogenic insulations for a Reusable Launch Vehicle, Johnson et al., NASA Langley

3 Proceedings of the RAND Project AIR FORCE Workshop on Transatmospheric Vehicles, Chapter 3: Design Option and Issues, containing X-33 general overview and info about the competitors, Gonzales et al, RAND Corporation

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Concept art of lunar bases tends to show spherical or cylindrical structures, but they suffer from one problem: radiation. (Both of the gamma / particle and heat kinds). The lunar environment has lots of solar and cosmic radiation. Nights also last for two weeks, during which a badly insulated thing will freeze.

If you bury your moon base under a layer of regolith, you can avoid both of these problems. You don’t have to bring heavy shielded modules from earth, or heat during the night with nuclear batteries. Regolith is thermally well insulating.

NASA seems to catch onto this a little in some clearly low budget “alternative configuration” posted at Nasawatch, but it only goes halfway, putting some shallow “berms” around cylindrical structures, for shielding.

In reality, lunar bases (if crews are to spend many lunar nights there) would probably be completely buried.

Burying might actually be easy: a small automated/remotely controlled snow blower style rover vehicle might be able to do it slowly with the help of just solar power. Since there is no air, tiny amounts of regolith can be thrown large distances. A thin wheel with whiskers spinning rapidly would throw the sand to the wanted direction. A lunar day is 336 Earth hours. Even if the “regolith lobber” robot can not survive the night and is expendable, it could manage to move significant amounts of regolith. A sub-MER size rover with large solar cells could throw perhaps 20 grams of regolith per second, or 72 kg in an hour. That’s 7 tons if there is 100 hours of efficient sand throwing time.

Say, landing at 50 hours from dawn, setting up 50 hours (survey area, lower rover from lander, unfold solar cells etc), operating for 150 hours (which includes maneuvering 50 hours and sand lobbing 100 hours), and finally stopping at a low sun angle 50 hours before dusk.

Such concepts are probably unlikely to work in an atmosphere, though I would be happy if proved wrong. The 2009 lunar regolith excavation challenge is coming up, after all…

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This time the Aerospace Corporation deems them suitable for launching Orion, tells a Nasaspaceflight.com article . Via Clark Lindsey.

I’ve gotten bored of all this a few years ago. When Griffin was in power, absolutely no change was considered.

From a quick look at the article, the Orion seems to have slimmed down considerably from the ESAS days (probably because of Ares I performance problems). The black zones myth has also been dispelled. Oh my. What do Doug Stanley and Mike Griffin say to that? Will there be  a congressional hearing about where the billions went, and why? Of course not, it’s space policy so no blunder or incompetence is technical ever – it’s all just happy equal opinions. The end part of the article is just bites from Griffin’s speech saying how the government doesn’t give enough money to NASA.

Seems also NSF is the only news outlet on the ball (I don’t really follow them all though, don’t know what’s been up at Florida Today for example). They got information weeks earlier but requested answers from the NASA side as well and got comments on this before making it an article.

Good work, Chris Bergin, the sources, all the people writing articles, as well as the forum people. I think the site was founded in 2005 so it’s been a swift rise to the top. Internet papers didn’t get any Pulitzers in the recent awards ceremonies, but in some specialist categories they might deserve good awards.

Perhaps space journalism prizes should be founded and given out every year.

In my view the CEV is still quite big, and thus the launcher alternatives are limited. Projected LEO versions of Apollo seated as far as six people. Though if Orion’s service module is refueled in orbit, the monolithic liftoff mass might be reduced considerably. The key is to have so light elements that you can use multiple launchers – which then on its own helps to ensure  improvability for the whole architecture since it’s not stuck with one solution from here to the end. The EELV launching is already a step in that direction, and miles better than Ares or Direct.

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I’ve been an opponent of Ares I for quite a long time (not from the beginning though, but I have become more of an optimist since, regarding better  ways). In light of these things, it might seem that the huge political and bureaucratic machine that is NASA can finally start turning around. Mike Griffin in his time changed the direction of NASA very quickly by firing a lot of leaders and starting the development of the Orion capsule and the Ares rockets based on the ESAS three month quick study. On the other hand, ESAS’ conclusions somehow ended with the industrial base not changing significantly. Still solid rocket boosters for example. So one can question, did the direction really change in that sense?

But if there’s a real change, it could very well be that an Orion (or some variant or derivative of it) could fly on an EELV. It is strange to an outsider that the ESAS (with references to unpublished appendices) claimed how EELV:s are less safe and more expensive than Ares I. Then there’s the whole “black zones” kerfluffle, that warrants its own entry, if true. Basically and oversimplified, NASA said the EELV:s need new upper stages since they have tiny engines in second stages which need vertical trajectories. The vertical trajectories are a problem in case of an abort, since they result in high G loads on the way down. But some people say the EELV guys were not consulted on this, and that they could easily fly shallower trajectories. Maybe I’ll post more about this some day with better references.

There are rumors around that a new NASA administrator has been chosen. While I do not think an EELV solution itself for US manned space access is smart in the long run, it is pretty good in the short run (next five to fifteen years). What is much much more important is that if there are multiple launch providers and the payloads are switchable between rockets, then that is a field where improvement is very easy and cheap, since one can introduce new launchers to the “launcher mix” without jeopardizing the whole “program”. (The program mentality is one big problem as well.) NASA is the biggest worldwide player in tonnage to orbit, by a huge margin. They have the bucks, and thus they control the spacefaring development of the world.

A lot hinges on the new NASA administrator choice. (Unless Griffin was really a puppet too.)

Expect to hear little

I expect mainstream aerospace journalism to be as apathetic about all this as before too. It seems there are relatively few technical people there, and hence they don’t recognize the whole existence of the difference between technical solutions, they are all equally good. To them, it’s just a political definition if Ares I works or not. Even programs like NASP, people like Rob Coppinger somehow think failed because of “politics” – I find they failed because of grossly unrealistic and unjustified technical assumptions right at the beginning. That again warrants a separate post (there are books about it already).

So, if you’re a politician, a space business person or a technical person working on the space sector, maybe you should read something else than the postmodern relativist lazy mainstream media if you want real insight… And probably actually at least many of the experts have already moved to other medias.

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It’s could be (and has been) said that he doesn’t follow the consensus – he’s ahead of it. But one has to be careful when making such bold claims of climate as Hansen has. Stoat has analysis.

Now I’m really off. I will return a few days later.

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I wrote this architecture proposal, FLEX, a few years ago. It analyzes NASA’s approach that the ESAS study picked and notices how most of the mass in a lunar exploration stack in LEO is actually liquid oxygen. By using a propellant depot, the LOX can be lifted with tankers and any launchers imaginable (I wouldn’t use a Pegasus though). The rest of the stack is also naturally divided into about 20 ton chunks: EDS with its hydrogen, the CEV crew vehicle (Orion) and the LSAM lander (Altair).

No new heavy lifters need to be developed, there is enough US, nevermind world launch capability to support a moon exploration program. Launchers can also be improved on the run, because they are not tied to the single use, nor is the use dependant on the single launcher, and because they can fly often, hence improvements are worth the investment. This all could be achieved much sooner and cheaper than the current approach, and is much more robust for the future.

Go read it if you haven’t.

There are some comments at an old Nasaspaceflight.com thread that deal with a lot of the common questions about it.

I really don’t have the faintest idea of the background knowledge level of the readership here so I don’t know how much basics I should give, so feel free to ask in the comments if anything is unclear.

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The Constellation program has been going on for about 3 years. Kicking off with the ESAS study of a few months, it still hasn’t settled very much about the architecture. Even the number of solid segments and liquid engines on the Ares I and V launchers are uncertain – issues which mean a lot for the infrastructure. A high launcher means VAB rebuilding. A heavy launcher means new crawler ways. Everything seems to be reassessed constantly.

Ed Kyle has documented the Ares I and Ares V history, while I discussed the future of Ares V here, the picture is from that post’s presentation. At the moment the design has moved along from the first configuration in January, having added half-segments, more core length and a sixth RS-68. No move to HTPB rubber in the boosters yet or composite wet parts EDS IIRC.

Ares V Evolution, Muirhead Jan 2008

Ares V Evolution, Muirhead Jan 2008

People from inside NASA have lamented the lack of conceptual design skills there, since the design keeps changing too much because of flaws being discovered.

There’s the classic story from Apollo, when Wernher von Braun simply didn’t believe the mass numbers the spacecraft people gave him, and vastly oversized the Saturn V – and it turned out that eventually all the performance was needed.

But the leaps in capabilities were huge back then. Now rocketry is routine and there is already one example of a lunar architecture to compare to. Not many new engines need to be developed for example, and a lot of the hardware is derived from STS and other flying systems.

So how is it that an agency getting 15 billion dollars a year is failing to pin down the mass numbers any better? Over ten ton sudden shortfalls in LEO mass seem to be a lot. Of course, it is a hard problem, and it’s easy to carp from the sidelines, but still…

What will the payload landed on the moon be? What propellants are used? What is the Altair’s or Orion’s mass? And work back from there to TLI mass and ultimately to launch from Earth, all with generous margins. And it has seemed that a certain cycle has formed. First a solution on Ares I is based on some logic linking it to Shuttle hardware, infrastructure or Ares V with common elements, which should save a lot of money and time and keep the workforce etc etc. Somewhat later, rumors about a severe performance shortfall on either launcher start circulating. Then after a while NASA announces a new configuration where the commonality is disrupted. And again forward we go.

The decisions made earlier are not supported anymore because new facts (performance problems) were realized later. But these decisions can’t be revisited. (Flying Orion on an EELV is one.) ESAS is referred to as having looked at all that, discarding it. Yet when some changes happen in Constellation, ESAS is mentioned as “only a 90 day study, how much can you expect from it?”. The consistency of decision justification is lacking. Ability for honest introspection is a rare thing for persons or organizations. I am just an outsider and don’t really know what’s going in inside there, maybe all is just exaggerated, but it looks troubled to me. How much can there really be progress if nobody knows what the launchers will be like in the end anyway?

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