Columbia Loss Adds More Support to Hypothesis

Alexander Sheppard · 2003-02-02 23:04:17

The recent loss of Columbia is a sad thing, and it lends yet more support to a hypothesis which, I think, the evidence for is already very developed. This is that the primary function of NASA, rather than to explore space in a way which benefits humanity (or even the US) as a whole, is to act as a subsidy for large aerospace and related corporations, the method of choice being the funding of very expensive projects in which output is only a marginal priority.

Now a lot of people have talked about NASA administrators trying to build empires, and I think there's some merit to that hypothesis as well, but we should be asking: who has the most to gain? NASA adminstrators or corporate stockholders? And who has the most power? A NASA administrator operates under fairly stringent controls ; corporate stockholders can do anything they want. So it seems reasonable to conjecture that although empire building is a priority for the people running NASA, it's a much larger one for the people running large corporations. Government agencies may have several factors driving them toward greater spending and power ; in a corporation that's just the stated goal. Of course, it should be kept in mind that in many places these organizations are virtually fused together, which is not suprising.

The grip of wealth on the decisions of Congress is doubtless large by any sane measurement ; it is no suprise that this wealth is rewarded with money that ought to be going to public programs. The integration of many parts of NASA, Lockheed and Boeing is often virtually complete as a bureaucracy.

As for confirming evidence, the picture for the past two decades has been rather bleak, as most of us are generally aware, I think. The space shuttle is not cost effective, nor will it ever be. Nor is the ISS--from the perspective of actual science it would, as far as I know anyway, be better used as a place to store experiments and visit periodically, sort of like Hubble, than as a constantly manned outpost. Science missions have often been bloated needlessly, lending more support to the corporate welfare hypothesis, and even then the work is often shoddy, as from the perspective of short term corporate profit it makes no difference whether the spacecraft actually works or not. Around the edges of the mainstream, small things sometimes crop up where science is the main priority, and this is where most of NASA's productive work gets done.

Phobos · 2003-02-02 23:56:21

I knew this was going to come up. Maybe we should just take some hints from our hero Stalin and his glorious agency the NKVD and arrest everyone related with the shuttle program and shoot the traitorous dogs for undermining the revolution. Then we'll put new staff in there and I'm sure seeing what happened to their previous counterparts they'll see to it the shuttle always land safe and sound.

Josh Cryer · 2003-02-03 00:11:30

Ahh, and a really old timer returns to leave us one post, only to disappear yet again...

Fairly good analysis, but we shouldn't approach it as if it's a conspiracy or anything (not that you are). It's simple, really. Aerospace industry sees opportunity to sell a technology to NASA and NASA says go for it. Aerospace industry capitalizes on the fact that NASA has limited budgets, and doesn't care if the job gets finished or not.

While listening to the Columbia coverage the other day, one of the many veteran astronauts came on to be interviewed. He finished his rather long discussion about why cutbacks occur, by stating that the real progress into space will be the result of individual aspirations (the pioneers), not a force which is limited by budgetary considerations or political motivations.

I personally don't think the technology we have now is not potentially cost effective. We're just mismanaged to hell and back, is all. The Shuttle was mainly used to test stuff in zero G (up until around the time of the ISS), this could be done on the ISS via science packs sent up with Russian style rockets. The Shuttle should have, and should be, used what it was designed for. Building stuff. Full payloads every trip, damnit!

I agree that we want to get rid of the whole ISS. We need a space station that has gravity. And we could build one. It's not all that impossible. Lots of Kevlar-Aluminum strips could be chained together (so that when inflated would weld themselves) to build, quite literally, a Babylon 5 style station. Of course, it's too late now to use the Shuttles for such an endeavour.

I've begun to not care about NASA's manned space initiative, as they clearly do not have one. I've moved my eyes to China.

Ad Astra · 2003-02-03 00:22:19

Now is not the time to use tragedy as an excuse to rail against some mythical and tenuous military-industrial complex. It is a time for reflection and reconsideration. Ever since Apollo, NASA has been an agency in termoil. The United States has always been a nation of technophiles; we watch with awe and amazement as the state-of-the art is advanced.

Some may question whether NASA was really making a significant contribution to science, and others will question the *real* motives of the NASA family. I think that ultimately, NASA is charged with boosting American morale with consistent displays of technological might. The thunder is gone from NASA's sails now, and the agency must find its direction again.

My personal feeling is that NASA should return to the bold vision it gave the world so long ago, during the heady days of space's "heroic age." Exploration should be the highest priority. This means going places that haven't been visited before, and doing so for the sake of curiousity and adventure. It also means making the adventure accessible to the greatest possible amount of people. I think the president made the right call on Saturday by announcing that the space program will go on, even though it would have been easy and tempting to kill it on the spot from a political standpoint.

I believe that a new challenge is necessary now to prevent us from becoming complacent with our current progress. The groundwork has already been set by Project Prometheus. The chance is here to cast off the proverbial albatross, the ISS. Priority one should be an RLV that is safer, cheaper, and flies more routinely than the obsolete STS. The second priority is a voyage to Mars. Setting such lofty goals is the only way to hold the short attention span of the American collective consciousness.

Josh Cryer · 2003-02-03 01:08:27

Who said something about a military-industrial complex?

Alexander Sheppard · 2003-02-03 04:40:28

It should be noted, too, that during NASA's peak productivity it had the most direct control over what corporations were doing, oversight was largest. Corporations began to become more autonomous following the Apollo era. That would also seem to contribute to the corporate welfare hypothesis.

It is a time for reflection and reconsideration

Which is what I am doing.

It should be noted that the corporate welfare hypothesis and the "government bureaucracy hypothesis" which has been circulating some time now don't conflict, they work together. It's just a matter of assigning relative importance.

I personally don't think the technology we have now is not potentially cost effective

Well, the shuttle orbiter isn't. The launch stack might be useful for something.

I think people ought to be somewhat interested in the welfare hypothesis, because, even if you don't agree with it, it is something which is different from the traditional viewpoint, which assigns the sole blame to government, mysteriously leaving out corporations, even though in many cases they are essentially a single entity, as Zubrin himself attests. Also, the welfare hypothesis allows for the possibility that "free market economics", that is, without government subsidy, would impact innovation in space quite badly, something which is obviously the case, looking backward.

Ad Astra · 2003-02-03 07:17:59

The fundamental problems of the Space Shuttle can be directly tied to the politics and policies of NASA, not really on any wrongdoing by the contractors. They developed the best system they could with the R&D funds that were allotted. A fully-reusable shuttle would have been desirable, but NASA had neither the money nor patience to develop it. It would also have been nice to use the monolithic solid rockets developed by Aerojet, or liquid fueled boosters, but these recommendations were overruled by NASA bureaucrats who favored Thiokol's design because the plant was located in Utah.

NASA's acquisition mentality has always been, "This is what we want our vehicle to look like, somebody build it for us." All proposals are for vehicles that are very similar to each other. It's about time NASA said, "This is what our new vehicle needs to do. Now go build it," and give the industry a carte blanche to be as innovative as possible. This almost happened with the X-33, but NASA ended up selecting Lockheed Martin because their design matched NASA's preconceived notion of what the vehicle should look like. Essentially, we need less, not more, micromanagement of the contractors by NASA.

Josh Cryer · 2003-02-04 09:14:18

Alexander,

It should be noted that the corporate welfare hypothesis and the "government bureaucracy hypothesis" which has been circulating some time now don't conflict, they work together.

Indeed, the two kinds of pork. There is actually a website for the whole, ?government bureaucracy hypothesis,? and they do make their case fairly well (nasawatch.info- expect a lot of political falderal of course). I actually find it funny that people complain about the some, say, 150 million dollars of bureaucratic pork that goes into schools and such, while neglecting to mention the contracts which have very little or no success and tend to just be holes where we throw money (ie, X-33 and other wasteful contracts which lead no where- I am certain that if I dug I could find many examples).

They're almost the same thing, damnit. But at least with the bureaucratic pork we get a school or observatory or whatever built. Whereas the other kind typically leads very little to no advancements at all.

Well, the shuttle orbiter isn't [potentially cost effective].

Well, we can get into the argument, if you want. But the Shuttle wasn't intended to carry people only, it was intended to carry large payloads into space. $500 million per launch is pretty cheap, because it translates to about $7500 a pound. As far as I know, humans don't have anything else capable of sending the same kinds of payloads (size and weight) the Shuttle does to LEO. Of course, this is not to say that I don't think we need a replacement (I've called for freezing the fleet), I'm just saying that at the momment it geniunely is the best we have.

Some people create the fallacy, ?But Russia can send three men into space for $20 million while the US spends $500 with the Space Shuttle!?

As if the freaking Space Shuttle's cost could ever be reduced to $20 million dollars or something. Right! The Space Shuttle does more than just ?send people into space.? It has, you know, this huge thing called a payload bay, and you know, you can put ?stuff? in it... 60k some pounds of stuff, in fact. I would be very very surprised if anyone could safely cut the cost of the Space Shuttle more than 150 million, hell, more than 50 million (it's bad enough as it is). Anyone calling for the privatization of the Shuttle fleet needs to get a clue, and those who want to privatize space, need to petition congress or the DOE or whatever so that they can use nuclear material in a rocket, or design an X-33 type system.

And Ad Astra, I don't think Alexander is talking about more micromanagement, I think he's talking about a more equitable contract system which doesn't allow corporate entities to run away with the cash. Changing contracts to make the private industry deal with more risk is a better solution than paying them regardless of success. People would have lost money on the Columbia accident (of course, their insurance would have probably covered their losses, but the point stands).

Alexander Sheppard · 2003-02-04 10:25:16

Well, the purpose of large corporations, remember, is not to innovate, or really to do anything, except make a profit (if that wasn't so, they wouldn't be large, or even exist). If you create conditions where a corporation has to innovate in order to make a profit, then there's going to be innovation ; if you allow conditions where corporations can afford not to innovate, there's not going to be any innovation.

Now, if you are in charge of a corporation and are choosing, say, what kinds of cantidates you want money donated to and what kinds of propaganda you want to fund, you're going to try and push the ideas that make you the most profit: in short, large amounts of government pork which go staight into your pockets, in return for as little as possible. I mean, that only makes sense, right?

So essentially, right off the bat, what I'd guess is that a serious problem with NASA right now is that there is a lack of oversight and a drive to just give out random contracts which do essentially nothing--a guess which seems to be amply confirmed by the most notable programs and the (fairly small) amount I've read on the history of NASA corporate policy. And what I'd also guess is that what is going to be required to help this situation is a long, hard fight, and one which intersects amply with other sectors of society, which face related problems.

The welfare hypothesis also seems to account for why politicians have been so reluctant to have the space program do anything meaningful: we need to ask, how do you get elected? How do you get in high positions? Well, there's a pretty universal rule about that: if you want power, you please the people who wield power. You don't oppose people with power. The only people who are going to get elected are people who aren't going to offend powerful people, and that means giving out lots of pork. Now, we can change that, but it's not going to be easy.

clark · 2003-02-04 11:13:01

I'm not quite sure I would agree with some others here on assessing the management, or mismanagement, of NASA. All this belly aching regarding the shuttle fleet, the ISS, or the "misdirection of NASA" is little more than opinion.

Could the Shuttle fleet perform better? Probably. However, let us not neglect the accomplishments, and the achievements that NASA, and the Shuttle fleet have achieved. As much as we may wish it to be otherwise, the technology used by the Shuttle is cutting edge. It is one of the most advanced pieces of developed technology that humanity has ever constructed. And guess what, it is expensive to operate. If it were as easy as we all wish it was, it wouldn't cost half a billion a shot.

Yes, the Shuttle fleet has tried to be all things to all people. Look into the history and realize that this result is a function of the Shuttle fleets coming into being. It needed political backing, so is it any wonder that NASA looked to meet the needs of other government agencies in order to get more political backing?

And those industrial contracts are a necessary component for maintaining national security. Lockheed and Boeing do a lot more than just NASA contracts. And when our only TWO aerospace companies don't have military contracts, they need NASA contracts to keep their engineers- you know, the ones that design and produce our nifty space satellites, rockets, and fighter planes.

If anything can be salvaged from this tragedy is perhaps a reassessment of how we operate our space policy in relation to humans to space.

The Shuttle seems ill suited in design concept because it mixes a human transport system with a payload delivery system. Getting humans to space has a different standard than getting several tons of cargo into space.

I would imagine that a space plane, for humans only- say getting 7 astronauts into space would be a good goal. And another system to launch cargo.

We talk about sending supplies to Mars before the humans set out for mars- why not apply the same logic to LEO? Launch the parts into LEO, and then let a human space ferry meet with it.

Ad Astra · 2003-02-04 15:20:33

I disagree with the assessment that the Shuttle is cutting edge. It was designed in the mid-1970's, and most of the technologies date back to the 1960's. The most cutting edge thing about it has been the upgrades, particularly in the way of the cockpit electronics.

The next manned launch vehicle must be better. It needs a robust thermal protection system, plus the electronics to detect and problems with the TPS. I hope that the ability to build such a system is in hand, and it could be fitted to the other orbiters before they are returned to service. The cutting edge of the late 1990's will hopefully be integrated into future vehicles in the form of health monitoring software. This will dramatically improve safety and shorten turnaround time.

RobS · 2003-02-04 16:12:04

The plans NASA had before the Columbia disaster were moving in the direction suggested by Clark. We have plenty of expendible boosters able to launch 60,000 lbs/25,000 kgs into LEO: the latest Delta and Atlas can do it, the future Ariane will be able to do it (if they ever build it!), etc. The launch costs are more like $150 million rather than $300-$500 million. So the shuttle's cargo lift capacity can be replaced by something cheaper. The aerospaceplane was to be designed to carry as many as seven people to the Space Station and would at first be lifted by the same expendible boosters, so the aerospaceplane would also have the same basic mass (which is 16 tonnes to the station, 24 tonnes to LEO). It would carry people up and would be faster to turn around. It would also have launch escape systems the shuttle lacks. It possibly would have one of the new metal heat shields NASA has been working on.

These two systems together could more or less replace the shuttle for lifting things to orbit. And if Atlas, Delta, and Ariane are all candidate launch systems, if an Atlas blows up you can keep going with a Delta until the Atlas is man-rated again. Then you can eventually replace all three with a reusable booster. That's the plan, and it makes sense.

The one problem with it that I can think of is that you have no cargo return capacity. The shuttle's cargo bay can bring the Hubble back to Earth, so it can go in the Smithsonian. That's a trivial example, but there are more serious ones involving scientific experiments. The aerospaceplane won't have much of a cargo capacity. But perhaps that problem can be lived with for a few decades until a new shuttle with a cargo bay is practical again.

The other problem is that this transportation doesn't help us with flights to the moon or Mars very much. My guess is that bigger rockets are not going to be built any time soon, so we'll have to develop ways to go to the moon or Mars using 24-tonne to LEO launch capacity. Michael Duke et al have shown that can be done for moon exploration, and I think it can be done for Mars as well (as anyone following my Mars-24 thread will know).

That is my guess for the direction things are going. No atmospheric nuclear rockets, no Saturn 5-like launchers (or Energias), and no space tethers. Tethers may be used by mid century; who knows. Meanwhile, we'll have to make do with 24 tonnes at a time.

-- RobS

KDM · 2003-02-04 21:56:15

Maybe we should all remember what the shuttle was designed to do, and how long it was designed to do it for. The shuttle was originally designed for transportation and microgravity experiments of NASA. The government then decided that a bigger payload was desired such that military applications could also be combined, and also at a lower cost.
The shuttle was doomed from this stage.
The shuttle was also designed to launch at a greater frequency than it has been proven practical, and was meant to have already been completely replaced by the next generation shuttle whose design was to incorporate new technology and learn from the failuires of the pevious shuttle. At this time, NASA have committed to using the Shuttle from the next 15 years, at least. BY then, we ill be flying 40 year old technology!!!!!

I must close by remembering the 7 heros who were willing to risk it all, as well as those who went before them, Challenger, Apollo 1 and also the Russians, for they to were just as brave.

We should all remember the words of a great man when considering the future of our space travel, that of Gus Grissom, Apollo 1 comander:

"The conquest of Space is worth the risk of Life"

dickbill · 2003-02-05 09:01:20

KDM the conquest of space does not worth life, at least not anymore. The time for superhero enduring 50 g at launch is over. We should not conquer space anymore, now we should explore and exploit space, and this is a job for Mr everybody (almost) and private initiatives.
Already, private compagnies can buy launchers to launch their telecom satellites. I am pretty sure that if a safe Heavy laucher like shuttle C was commercially available, the space exploitation would be much more advanced.

tim_perdue · 2003-02-05 19:51:53

I, for one, think NASA's unmanned program is awesome, and truly does contribute to science. Projects like Hubble, Galileo, Odyssey (there are countless dozens, really) are truly technological marvels that have returned a great deal of science. Hubble really stands out in my mind as a true gem and marvel.

My opinion of the manned program is not as favorable. Unfortunately, they have made space travel so boring as to be intolerable, even for technophiles like myself. The NASA channel is obscenely lame and a self-destructive force. I can watch C-SPAN for hours, but cannot tolerate 15 minutes of NASA channel. There guys appear to be using 1960's era video cameras, 10 years after DirecTV started beaming down 100% digital crystal-clear video from space.

Clearly, the shuttle and ISS are an albatross around the neck of any hopes for a space-based future for humanity. I have said many times in the past few days, that this is an opportunity to put the shuttle in a museum and splash the space station, and put our dollars into cost-effective and commercially-viable space transport. If you can reduce costs an order of magnitude, or two, you can have an entire industry develop.

I believe we can do it, technologically, if NASA's money were spent right, and it would enable a truly great explosion in private space exploitation, as opposed to the boring charade of launching the shuttle.

soph · 2003-02-05 20:09:00

Congress has to approve anything. Unfortunately, now that we have started the ISS, to splash it would kill the space program more than it would help.

We need research programs on the magnitude of NERVA. NERVA is a great example, because in 10 years they made remarkable advancements in NTR technology, and this was with 1960's technology. If we restarted this program today, truly cheap and reusable SSTOs could be developed in 5-10 years. Doing some math earlier with a little input from another board member, we calculated that you could theoretically, using NERVA technology, get near 50% of the initial payload into orbit.

Compare this to shuttle, where about 100,000 kg gets to orbit out of a total launch mass of 2 million kg. Out of that 100,000 kg, 25,000 kg is payload that can be brought and left in space. 2 million kg to get 25,000 kg into space?

Granted, you need hydrogen tanks for an NTR, so lets say you have 10 tons of tankage per 100 tons. Even 20 tons. Since the rocket is included in the orbiter itself, and is reused, you dont waste 600,000 kg on a rocket that is left behind.

The larger an ntr is, the more efficient it is. As structure falls into the noise, so to speak, the ntr's efficiency is magnified. So the only major weight is the hydrogen and its tanks. Peronally, i would keep these all mission, up until landing. The higher isp means a greater exahust velocity, which also means you can carry more. The tanks could be reusable too, and you could have propulsion options all mission. this means, given any inefficiency, tank weight, and so on, you could still get at least 25%-30% of your mass to orbit as payload. This means 500,000-650,000 kg for a 2 million kg launch weight. This would a 1 million ton orbiter, at least!

tim_perdue · 2003-02-05 22:29:09

We need research programs on the magnitude of NERVA. NERVA is a great example, because in 10 years they made remarkable advancements in NTR technology, and this was with 1960's technology. If we restarted this program today, truly cheap and reusable SSTOs could be developed in 5-10 years.

I think Bush is doing exactly that. I wouldn't be surprised if he comes out with a bold initiative, although it may have to wait until after Iraq. My idea of a "bold initiative" is not necessarily going to mars, but to build a truly usable space plane, and of course Bush doesn't give a damn about "envirofascist" opinions.

These guys (the Bush Regime) have a lot of reasons for supporting space: 1) it's a voting block, albeit small, it can offset the environmentalists that Bush hates so much. 2) Handing out pork to Texas and various powers that installed him, and 3) Militarization, which is obviously one of his obsessions. 4) I think Bush wants to be able to say he has a vision beyond just warmongering. You saw little rays of that in his last SOTU address.

So I'm expecting this regime to capitalize on this "opportunity" as any politician would, and do something big. They were, after all, already fully funding the NSI before the columbia tragedy on saturday.

KDM · 2003-02-06 17:11:07

Instead of all this talk about slashing the ISS, ditching the Shuttle and praising unmanned missions, should we not consider what many of us hold as a dream.
I still want to see, in my lifetime, man walk on MARS. An unmanned mission cannot accomplish anywhere near as much as one where we put humans on another planet where they explore, gather, test and live for a period of time. The ISS is meant to be used to answer some of the unknowns, especially how we can develop means that humans can live in space for long periods of time without serious muscle and bone degredation. These answers are vital to a manned Mars mission.
To accomplish this, we need to continue manned missions to the ISS and on other scientific experimental missions, such that our knowledge can be increased. To do this, the Shuttle and Russian rockets are required.

Space is still a frontier, and one which man wants to explore. It is still a conquest as we try to understand such that we can reach out further and further into the unknown. The reason we are not accomplishing much isn't just due to bad decisions on projects, but that many of us have lost the vision.

I still want to be alive when man walks on Mars, and hopefully involved in the mission in some way. Man will still look to the stars and wonder what is out there, and through the use of both manned and unmanned missions and projects, maybe we will discover.

Palomar · 2003-08-07 11:53:45

Asteroids Named for Columbia Astronauts

*And I think that's a wonderful idea.

--Cindy

prometheusunbound · 2003-08-12 14:42:30

soph, what are you talking about?

Doing some math earlier with a little input from another board member, we calculated that you could theoretically, using NERVA technology, get near 50% of the initial payload into orbit.

Show me the math! I am desperate for info on NERVA.

If that is the case then lets do it!

Palomar · 2003-08-26 10:51:19

"Report Warns NASA Needs Sweeping Changes"

--Cindy

RobertDyck · 2003-08-26 17:24:06

Doing some math earlier with a little input from another board member, we calculated that you could theoretically, using NERVA technology, get near 50% of the initial payload into orbit.
Show me the math! I am desperate for info on NERVA.

Math for launch vehicles, I can't resist. I once did look at replacing the aerospike engine on a VentureStar or X-33 with a NERVA, and the result looked like a very significant lift mass to LEO, but the mass of the NERVA itself was bad. Let's look at a TimberWind-250 engine on the configuration of VentureStar described in Astronautix.com.

That configuration has a launch mass of 991,000kg, empty mass of 89,300kg, a payload capacity of 26,800kg to 185kg orbit at 28.0 degree inclination. It used 7 RS-2200 engines with specific impulse of 455 seconds in vacuum, or 347 seconds at sea level, and a thrust in vacuum of 224,540kg force. I don't know the engine mass, but the SSME is 3,177kg. The Timberwind-250 has a thrust of 250,000kg force, mass of 8,300kg, specific impulse of 1,000 seconds in vacuum, or 780 seconds at sea level. Specific impulse is how many seconds can the engine generate 1 kg force of thrust using 1 kg mass of fuel. The Isp ratio in vacuum of RS-2200 to Timberwind-250 is 0.455, at sea level it is 0.44487. To simplify the calculation, let's use an average of 0.449935. The fuel load of VentureStar is 991,000 - 89,300 - 26,800 = 874,900kg. Using the Isp ratio the fuel load using Timberwind-250 engines would be 393,648kg, or 481,252kg less. To get sufficient thrust, you would need to replace the 7 RS-2200 engines at 3,177kg each with 7 Timberwind-250 engines at 8,300kg each. That increases the spacecraft mass by 35,861kg. The payload mass is increased by the reduction in propellant mass, but reduced by the increase in engine mass. 26,800kg + 481,252kg - 35,861kg = 472,191kg. That is not accounting for reduction of tank mass or increase in payload bay walls or doors. Does anyone know what to do with a 472 tonne payload lift capacity? That is a ratio of total launch mass to payload of 472:991 = 47.6%.

The X-33 was much smaller. It has a gross mass of 123,800kg. The Timberwind-75 engine had an Isp in vacuum of 1,000 seconds, and 890 seconds at sea level. That is even better at sea level. The thrust was 75,000kg in vacuum, and engine mass of 2,500kg. To keep the thrust to gross mass ratio the same as VentureStar you would need 2.6 of these engines, so say 3 engines that are throttled. Rather than go through an extensive calculation, let's steel the launch mass to payload ratio we calculated above. That would give us 58,928kg to 185kg orbit, or 34,393kg to ISS. The current space shuttle can lift 16,050kg to ISS, but it also has a cabin for astronauts and robot arm.

These numbers sound dramatic until you calculate tankage. The propellant for a conventional engine is LOX/LH2, but a NTR engine is just LH2. A tank for LH2 is much bigger. The heat shield to protect the bigger LH2 tank would mass much more than the tank itself. This larger heat shield could negate the increased cargo capacity. Here's a problem for you budding rocket scientists: design a LH2 balloon tank that can be collapsed and stowed in a small volume for re-entry. It would have to be reusable, yet able to withstand cryogenic temperatures when full and structurally strong enough to hold tonnes of liquid hydrogen. Perhaps a semi-soft balloon with a netting cup holder?

prometheusunbound · 2003-08-26 17:57:10

hot damn!!!

Does anyone know what to do with a 472 tonne payload lift capacity? That is a ratio of total launch mass to payload of 472:991 = 47.6%.

What are we waiting for? Lets have a revolution, overthrow the gov and have a space utopia, forget everyone else. Thats what we can do with 47%. . . . . . .(yes, I am really kidding all of you guys)

Echus_Chasma · 2003-08-27 00:18:47

The New Zealand News about 5 minutes ago, said a report had been released into the Columbia crash which points the blame at NASA itself. It said something like NASA had it's prioties wrong when it came to safety and they ignored some signs that things were going wrong. That pretty much lines up with what a radio programme said about 20 minutes ago.

Hmm, I think that is the report Cindy is refering to.

Shaun Barrett · 2003-08-27 04:25:13

Hi Robert!
Thanks for the illuminating run-down on the VentureStar performance figures and how a Timberwind-powered version might perform.
The bottom line is indeed impressive, moving up from a payload of 27 tonnes to 472 tonnes!

But your objection to actually building such a vehicle has me a little puzzled. The optimum LOX/LH2 mixture is four times denser than LH2 alone. I assume from this that we need to carry four times the volume of fuel for the Timberwind nuclear option(?)
If the fuel were carried in cylindrical tanks (which is not the case with VentureStar, I know), doubling the radius of the cylinders would achieve the volumetric increase required. If the tanks were spherical (again not the case, I realise) the radius of the spheres would only need to be 60% greater to get the amount of LH2 needed.

These dimensional increases don't seem, at least on the face of it, to be too dramatic. Why not just make the VentureStar dimensions a little larger?
I realise 'a little larger' means rather more in practice than it appears in theory, but surely even increasing VentureStar's empty mass by 50% to 134 tonnes, to enlarge and strengthen it, would still result in a respectable payload-to-orbit ... or would it? Perhaps I'm underestimating the problems here(?).
???

Incidentally, did someone say Timberwind is not the 'cleanest' kind of NTR, or am I daydreaming? I understand all this is just an exercise in mental engineering and Timberwind is a convenient 'off-the-shelf' engine to consider, but are there theoretically cleaner and/or more efficient NTR's which might enhance our tonnage-to-orbit figures still further?
Just a thought.
Once again, thanks for a stimulating tour of fantasy spacecraft of the 'didn't-quite-make-it' future!

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Re: Columbia Loss Adds More Support to Hypothesis

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Re: Columbia Loss Adds More Support to Hypothesis

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Re: Columbia Loss Adds More Support to Hypothesis

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Re: Columbia Loss Adds More Support to Hypothesis

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Re: Columbia Loss Adds More Support to Hypothesis

#11 2003-02-04 15:20:33

Re: Columbia Loss Adds More Support to Hypothesis

#12 2003-02-04 16:12:04

Re: Columbia Loss Adds More Support to Hypothesis

#13 2003-02-04 21:56:15

Re: Columbia Loss Adds More Support to Hypothesis

#14 2003-02-05 09:01:20

Re: Columbia Loss Adds More Support to Hypothesis

#15 2003-02-05 19:51:53

Re: Columbia Loss Adds More Support to Hypothesis

#16 2003-02-05 20:09:00

Re: Columbia Loss Adds More Support to Hypothesis

#17 2003-02-05 22:29:09

Re: Columbia Loss Adds More Support to Hypothesis

#18 2003-02-06 17:11:07

Re: Columbia Loss Adds More Support to Hypothesis

#19 2003-08-07 11:53:45

Re: Columbia Loss Adds More Support to Hypothesis

#20 2003-08-12 14:42:30

Re: Columbia Loss Adds More Support to Hypothesis

#21 2003-08-26 10:51:19

Re: Columbia Loss Adds More Support to Hypothesis

#22 2003-08-26 17:24:06

Re: Columbia Loss Adds More Support to Hypothesis

#23 2003-08-26 17:57:10

Re: Columbia Loss Adds More Support to Hypothesis

#24 2003-08-27 00:18:47

Re: Columbia Loss Adds More Support to Hypothesis

#25 2003-08-27 04:25:13

Re: Columbia Loss Adds More Support to Hypothesis

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