SpaceX's Dragon capsule captured by ISS

[93143]

I said: "As I know russian progress and top models of french arian". I think that is does not mean "I am sure".

It's not a grammatically correct statement, but the use of the word "know" does indeed imply that you are sure.

The phrase "as far as I know", on the other hand, implies that you are not sure. Your statement is not immediately identifiable as a permutation of this.

Please simply inform maximum payload carried by shuttle, orbit on which that payload was delivered and than let's compare.

Shuttle payload was dependent on target orbit and crew size, and changed significantly over the life of the program, but the nominal figure was approximately 24.4 metric tonnes to 130x130nmi 28.5°. IIRC it would be a couple of tonnes higher if it weren't for a change in flight rules after Challenger, but I could be wrong about that.

High-energy performance with Centaur-G' was also extremely impressive, but of course after Challenger no one was willing to put a cryogenic rocket stage in the payload bay...

I think if you are making your PhD in physics, so, your source of information is the same as mine - internet.

Aerospace engineering, actually. My first two degrees were in mechanical engineering. My information on this specific topic is mostly from the internet, but that doesn't mean it should be disregarded. I am a long-time member at nasaspaceflight.com, which is an excellent place to learn stuff if you have patience because a lot of experts post there, a lot of inside information becomes available there (especially L2, which is the pay section, but I'm not on L2), and a lot of good references are linked. (It's also a lot more heavily moderated than here. You will not get away with insulting someone's mother on that forum.)

And I have worked on the design of an orbital launcher. In fact, part of my Ph.D. is based on simulation of the main engine. This does not make me an expert on the topic we're discussing.

You just can't use them to do it *twice*.

To hell with "twice" if two times of different lauch vehicles allow you to do the same job at lower cost. What this is called in English? Not "cost effectivness"?

Exactly. Which is the real reason why the shuttle program finally got the axe.

Non-reusable launch platforms beat it on cost while still being able to do everything it did.

Actually, that's not the reason. Shuttle was cancelled for safety reasons. It was a knee-jerk reaction to Columbia, that no one ended up having the foresight to do much about until it was too late. (Also, Griffin needed the money for Ares.) We were very lucky they managed to get STS-135 flown; the station would have been in severe trouble if they hadn't...

It's also not strictly true. My calculations indicate that expendables are only really solidly cheaper for missions that don't fully utilize Shuttle's capabilities, such as satellite launches. Also, a number of STS capabilities, such as space tug functionality and large downmass (particularly unpressurized), have only ever existed in STS (Buran was never operational and doesn't count), and are now gone. You could develop them, but that takes significant amounts of both time and money. They don't exist now, which makes your statement untrue.

Now, if you factor in development and whole-life operations costs (it used to be more expensive), you can get a very high figure for Shuttle cost. But since those costs are sunk, they can't have been a reason for cancelling it, now can they?

You could argue that Shuttle was underutilized in the station support role, and that we will save money by using commercial providers. It's probably true, but that's due to a combination of factors and not Shuttle's fault (except inasmuch as Shuttle was rather easy to underutilize). At its usual launch rate, fully loaded, the cost of combined crew and cargo to ISS on Shuttle seems to have been roughly comparable to the CRS contract for Dragon.

...

Shuttle was not just a launch platform. It was also a spacecraft. A large, versatile manned spacecraft, with a cargo capacity exceeding the payload capacity of all but the very largest expendable launchers. Comparing Shuttle to Delta IV Heavy is a little like comparing Soyuz to Shtil'...

Shuttle got the axe because it ran its 30 years as expected, and to keep such old spacecraft in service would have escalated costs well beyond what they already were, and sucked up any funds to build a replacement. It is technically not true to say it "got the axe". Rather, the program ended when expected.

That's not true either. The stuff about the orbiters being "old" is absolute nonsense; they were roughly a third of the way through their design lifetimes and doing very well, with record low numbers of issues per flight and the safest operation the program had ever seen. The ASAP's call for "recertification" was either ill-informed or politically-motivated; basically everything they asked for was done during RTF, and most of it during ordinary preflight operations. The system did "got the axe" after Columbia, and nearly left the ISS high and dry because the U.S. government can't plan worth a ####.

Ever heard of the SSME Block III? It would have finally achieved the robustness and reusability envisioned at the start of the program, and been cheaper to manufacture into the bargain. It was supposed to enter service in 2005. Where is it?

It's true that it would have cost more to restart STS after 2008. But apparently more than one commercial entity was willing to shoulder that cost, and one of them didn't even need NASA to buy any flights afterwards.

It's also true that if NASA had continued Shuttle, especially indefinitely (which I've never advocated, not as a government program anyway) Congress would probably have balked at funding a replacement (commercial seed money, SLS/Orion, Shuttle-II, what have you) at the same time, and the President probably wouldn't have tried to make them. That's the government's problem; it doesn't have anything to do with the intrinsic ability of the United States to pay for it.

[Skipjack]

Yep. They could have built 5 vehicles instead of one. If you think that would have been cheaper you're right out of your mind.

Not 5 but maybe two or three. Not all have to be reusable either. Some jobs could have been done by expendable vehicles, as they actually were anyway (for cost reasons).

Next-gen shuttle already exists. It's called X-37.

Very good example of a much better and much more focused design than the original shuttle had. It still does have the crossrange which is mainly due to its military use, but it is not a heavy lifter and only transports cargo (so far, the crew version of the X37C might one day transport people).
It was also developed incrementally.

[Joseph Chikva]

Shuttle payload was dependent on target orbit and crew size, and changed significantly over the life of the program, but the nominal figure was approximately 24.4 metric tonnes to 130x130nmi 28.5°.

This is quite big payload. And I recalled this number as I had an about 30 years old book in Russian of academician Pheoktistov in which was analyzed the Shuttle program and there was estimated the cost of carrying of 1 kg payload on typical orbit as IIRC 30 USD. As I understand this number was based on American estimation. Then Russians (Soviets built “Buran” that is very very similar to Shuttle. And cancelled the program very soon from the beginning.

I granted that book together with many others to my father’s University’s library when they made decision to call one auditory my father’s name.

Now in this morning I’ve just made searches and entered in Russian launch vehicles producer’s web-site. Quick search gave me about 6 tones. So, may be I was wrong saying that Shuttle has not advantage in cargo capacity. And may be not wrong.
But also we should agree that in principle it is not a big problem to design and build launch vehicle capable to carry even 50 tons to the same orbit.

So, I assume there were very optimistic estimations of cost of Shuttle program in its beginning. Not true?

My information on this specific topic is from the internet, but that doesn't mean it should be disregarded. I am a long-time member at nasaspaceflight.com, which is an excellent place to learn stuff if you have patience because a lot of experts post there, a lot of inside information becomes available there (especially L2, which is the pay section, but I'm not on L2), and a lot of good references are linked. (It's also a lot more heavily moderated than here. You will not get away with insulting someone's mother on that forum.)

And I have worked on the design of an orbital launcher. In fact, part of my Ph.D. is based on simulation of the main engine. This does not make me an expert on the topic we're discussing.

My respect!

Shuttle was cancelled for safety reasons. It was a knee-jerk reaction to Columbia, that no one ended up having the foresight to do much about until it was too late.

What is the most critical factors for safety?
Two accidents: one caused as I know (as far I know? ) with rocket booster’s failure and the second with losing of thermal insulating tiles.

[93143]

But also we should agree that in principle it is not a big problem to design and build launch vehicle capable to carry even 50 tons to the same orbit.

Of course it isn't, in principle. It's been done, after all. Heck, both Shuttle's and Buran's basic launch vehicle structure could do considerably more than that if you simply left off the orbiter; Energia could do it right out of the box, but STS would have required some development (NLS, Shuttle-C) because the main engines were on the orbiter instead of the tank... I was just objecting to your statement's factual correctness (or lack thereof).

So, I assume there were very optimistic estimations of cost of Shuttle program in its beginning. Not true?

True. Shuttle was supposed to be something that no one has yet managed to produce - cheap access to space. It was certainly very capable, but it was hobbled by a set of conflicting requirements (which it met) and a development budget half the size NASA said they needed (which it overran by about 17% if I recall correctly; not bad at all for such an ambitious project). As a result, it failed to be the massive improvement over expendables it was intended to be. Worse, it was treated as a final result, with the government cancelling or refusing to fund realistic follow-on systems or even major upgrades. It was incrementally upgraded over its lifetime, and ended up significantly cheaper, safer, and more capable than it had been at the start, but ELVs progressed too and the gap in basic payload launch cost got large.

Shuttle was cancelled for safety reasons. It was a knee-jerk reaction to Columbia, that no one ended up having the foresight to do much about until it was too late.

What is the most critical factors for safety?
Two accidents: one caused as I know (as far I know? :) ) with rocket booster’s failure and the second with losing of thermal insulating tiles.

The booster field joint leak that impinged on the ET on STS-51L was due to a management decision to launch after a cold night resulted in a temperature excursion outside the certification range. Engineers protested. Afterwards, the vulnerability was fixed. O-ring blowby had previously occurred, showing up especially on STS-51B and 51C, but the redesigned boosters after 51L had no further problems of that nature.

The orbiter breakup on STS-107 happened after a suitcase-sized chunk of foam came off the external tank, was entrained in the airstream as the vehicle accelerated, and struck and damaged the RCC paneling on the leading edge of one wing. Engineers wanting to try to image it on orbit were ignored, and the wing failed on reentry. The foam shedding problem was mostly mitigated, including removal of the design flaw that caused the incident (previous liberations of the same chunk of foam had been ignored by management), but the tank continued to lose a few small bits all through the rest of the program. On-orbit inspection became standard, and combined with the Launch-On-Need policy (having a prepped stack ready to launch in case of emergency), or alternately the ISS safe haven (they used the LON stack for the very last mission), would have prevented another loss of crew.

STS-8 seems to have had a near miss with a faulty booster nozzle, that was apparently about 14 seconds from burn-through by the time the boosters burned out and separated. This one was also fixed; it was apparently just a bad batch of resin. Probably not relevant to post-Columbia safety.

STS-27 (a classified DoD mission) had severe tile damage, more than 700 tiles dinged with one completely gone. Apparently a booster nose cap shed ablative insulation all over one side of the orbiter. Presumably something was done about this; as far as I know it never happened again...

Theoretically, an improperly cured booster could become blocked with a chunk of loose propellant and explode without warning, but they were pretty careful about that, being well aware of the risk.

Also, apparently there was a small risk (1 in 1283 for a 3-engine cluster) of an SSME undergoing rapid unscheduled disassembly. The Block III was supposed to reduce this to 1/2960 with robustness improvements and an advanced health monitoring system.

If one booster ignited significantly before the other, the stack would be overstressed and possibly come apart on the pad. A complete failure of one booster to light would cause the other booster to flip the stack into the ground. I don't know how likely either of these scenarios were, but I suspect they weren't all that likely; solids are not that hard to start reliably.

I suppose if you had a guidance failure, entailing failure of the four primary computers plus the backup computer (which used a completely different codebase), or perhaps a massive multiple failure in the TVC systems or something, the range safety officer could be forced to initiate destruct. Shutting down the main engines and separating from the tank might have been possible, depending on the failure, but the boosters could not be turned off, and there was only a very short period right before booster burnout in which the orbiter could separate and try to get clear without being caught in the booster exhaust plumes. Lack of a LAS really hurts this scenario, but again I'm not sure how likely it was; multiple redundant (and independent) systems would have to all fail for this to occur...

Similarly, a loss of control on reentry would probably cause the vehicle to break up or crash. Bailout was possible below 50,000 ft, but if (say) the vehicle suddenly nosed down at Mach 5, the windows would blow in. Again, multiple redundant systems... and let me point out that the Shuttle's flight software was maintained by what was quite possibly the best programming team in the world; the code was compact, extremely well-tested, and widely acknowledged to be pretty much the least buggy software of any kind anywhere, ever...

Other than that I'm not sure. There were various minor risks that were all taken into account in preflight risk assessments, and I saw a summary of one once, but I can't remember it well enough to be confident in quoting it...

By all accounts the safety culture at NASA after STS-107 was very good. They'd learned their lesson, and the missions between RTF and end-of-program were the safest in the program's history.

A number of potential problems, notably non-catastrophic main engine failures, could force an attempt at intact abort. Abort to orbit (ATO) actually happened on STS-51F when multiple sensor failure shut down an engine prematurely; the mission was a success after some replanning. Transoceanic abort landing (TAL) would have been an option if ATO wasn't, leading to the unusual launch requirement of good weather at an airport thousands of miles away. Return to launch site (RTLS) involved turning around (after booster separation, of course) and trying to get back to Kennedy. I've seen a video of a simulation where all three main engines failed in progressive fashion, forcing the crew to abandon the RTLS attempt, drop the tank and try to ditch safely in the Atlantic. RTLS was considered very dangerous, probably since it would have stressed an already malfunctioning vehicle quite hard, but like TAL it was never actually used...

[Skipjack]

Shuttle was supposed to be something that no one has yet managed to produce - cheap access to space. It was certainly very capable, but it was hobbled by a set of conflicting requirements (which it met) and a development budget half the size NASA said they needed (which it overran by about 17% if I recall correctly; not bad at all for such an ambitious project). As a result, it failed to be the massive improvement over expendables it was intended to be. Worse, it was treated as a final result, with the government cancelling or refusing to fund realistic follow-on systems or even major upgrades.

Exactly and that is my issue with the shuttle.

The booster field joint leak that impinged on the ET on STS-51L was due to a management decision to launch after a cold night resulted in a temperature excursion outside the certification range.

The decision to use SRBs instead of liquid fly back boosters as originally intended was both a political and a financial decision. It was a bad choice.
The SRBs are among my main issues with the shuttle (that and the external tank and the tiles which all were a result of the other requirements and politics).

The orbiter breakup on STS-107 happened after a suitcase-sized chunk of foam came off the external tank, was entrained in the airstream as the vehicle accelerated, and struck and damaged the RCC paneling on the leading edge of one wing.

Part of the reason for that was the decision to side mount the shuttle to the tank which is the source for a whole lot of issues including a reduced amount of abort modes.

Fact is that the shuttle had a whole bunch of issues, which luckily not all resulted in catastrophic failure. It is safe to assume that it has even more that simply were not discovered yet by the time it was retired.

IMHO it was simply a too ambitious vehicle for the time. They should have rather started with a less ambitious but more economic and fully reusable crew transporter. Transport 3 or 4 people or the equivalent in cargo to a spacestation with a fully reusable launcher and you have achieved something great. The rest can be done with ELVs until the technology has matured and the kinks have been fixed.

If they had only dropped a couple of the requirements on the shuttle a much simpler, fully reusable vehicle would have been possible.
But they had to do it all and that failed and forever burned the idea into peoples heads that RLVs are not possible and wont be economical and that sucks!

[Joseph Chikva]

...

Ok, thanks. Very interesting to read.
But sometimes detailed information screens the bathing on a surface true. And true is simple:
-Shuttle program is canceled
-USA still needs vehicle aloowing space access.
What does this mean?
I think that this mean that Space Shuttle can not answer to requirements. And for NASA today is more preferable to use own single use launch vehicle technology or to ask Russians or Frenchs.

[GIThruster]

The decision to use SRBs instead of liquid fly back boosters as originally intended was both a political and a financial decision. It was a bad choice.

I would agree with this, but it was originally sold as a safety choice, as solids are much easier to manufacture and transport and don't require the same safety precautions as other types. This was the justification for the stick as well. Interestingly, solids are not safer for all the reason mentioned above, and yet they are again part of the SLS and were part of Constellation, Direct etc. Everyone plans to prop up ATK. It is a political choice now, but originally I think it was intended to be a safety first choice.

The much more serious problem was the ice shedding off the tank, which was a problem built into literally every iteration from 1969 onwards, including the fully reusable proposals from private industry, which were never much considered because the Air Force had already shown they would be too expensive. You can call the side by side decision a bad choice, but hindsight is 20-20.

[Skipjack]

would agree with this, but it was originally sold as a safety choice, as solids are much easier to manufacture and transport and don't require the same safety precautions as other types. This was the justification for the stick as well. Interestingly, solids are not safer for all the reason mentioned above, and yet they are again part of the SLS and were part of Constellation, Direct etc. Everyone plans to prop up ATK. It is a political choice now, but originally I think it was intended to be a safety first choice.

You would not transport liquid fly back boosters fully fueled, but rather fuel them on site...

The much more serious problem was the ice shedding off the tank, which was a problem built into literally every iteration from 1969 onwards, including the fully reusable proposals from private industry, which were never much considered because the Air Force had already shown they would be too expensive. You can call the side by side decision a bad choice, but hindsight is 20-20.

When the airforce got involved, was when all the problems started.
Otherwise they could have built somethig like the Phoenix VTOL, or the other VTOL designs that were discussed at the time.
If they had decided to make the shuttle just a crew transporter or just a cargo transporter (with the crew cabin being replaced with a cargo container), they could have built a much smaller and much less problematic vehicle, that could have even had a good crossrange.
The problem is that they wanted everything and they had to do it for a limited budget at a time when the technology was not matured enoguh yet. That meant design compromises and these design compromises resulted in all the issues that the shuttle had.
Then they made the same decisions again for the Venture Star as if the shuttle had not tought them a thing. And of course that failed too.

[ladajo]

Well, ahh. nope. There are things that shuttle did that sinlge use can not do.

Name one.

Down mass?

Stop being so obvious. Let them figure things out on their own.
Next you'll start talking about on-orbit manueverability and modular payload bays. Then they'll figure out even more...

[ladajo]

And why do you think that we, the US, continue to develop and field multiple use spacecraft?

I do not think so. But think that future technology will revive idea of reusable use spacecaraft. As on base of today's level of technology embodiment of such idea is not cost effective.
And why do you think that there are thing shuttle can do and single use craft cannot? I asked you and am asking once again:
-payload advantage?
-lower acceleration with allowing of transport of g-sensitive equipment?
I see only one advantage - roomy space and big manipulator. But manipulator can be installed on any craft. If you have space restriction you can make that telescopic. I am sure that critical is only one factor: namly cost of transportation of 1 kg. And nothing more.

Obviously you still don't get that what went up could come down. It is not a micro capsule parachuting in. It is a fully functional vehicle with massive payload bay that can take stuff up, and, BRING STUFF DOWN, in a controlled manner. Single use vehicles bring little things back, sometimes, and not always in a controlled manner.

[93143]

Skip, I know I said I wouldn't respond to you, but that was a surprisingly reasonable post. I would however like to object to a couple of points:

It is safe to assume that it has even more [issues] that simply were not discovered yet by the time it was retired.

I don't think that's a safe assumption, not if you mean significant safety hazards. Both fatal accidents were the result of ignoring known problems. The Shuttle program as it was after STS-107 would not have ignored known problems, and 135 flights should have been plenty to shake out any major unknown unknowns. Shuttle was extremely well characterized by the end of the program.

But they had to do it all and that failed and forever burned the idea into peoples heads that RLVs are not possible and wont be economical and that sucks!

Shuttle did no such thing. Everyone who knew that Shuttle wasn't delivering on its promises knew why. NASA kept trying - Shuttle-II, X-30, VentureStar, the Space Launch Initiative - even now, they're working on various hypersonics and advanced propulsion technologies. Others kept trying too - HOTOL, Delta Clipper, Sänger II, Kistler K-1. This stuff really is hard, as much from a funding perspective as from a technical perspective (not all of the abandoned schemes failed technically).

In fact, if I had to blame Shuttle for something, it would be being good enough - if anyone could have improved on it, it was NASA, but none of their follow-ons were ever funded to completion because the U.S. government has ADHD and couldn't be bothered to replace something that worked. (I suspect that the overreach of VentureStar might have been partly an attempt to make the project shiny enough to fund; if so, it obviously backfired...) This doesn't explain why no one else managed it either, of course...

The expendable launch picture has changed radically since Shuttle was first flown. Commercially-viable launch services were just not possible then or for decades afterward; only government-funded systems could hope to compete. The EELV program was intended to take advantage of the fact that the market had evolved sufficiently to support a commercial endeavour, but it turned out it hadn't; they got undercut by heavily-subsidized European and Russian rockets and ended up tools of the Air Force. The market has evolved since then, which is one reason SpaceX appears to be succeeding; the other is of course their energetic and transformative approach to low-cost high-quality service. Basically an organizational improvement, combined with a pragmatic approach to technology. Plus a lot of help from NASA, both technically and financially. And it's still not clear they'll be able to sustain it.

If SpaceX manages to get an RLV running and actually save money by using it, it will be because they were able to run a successful business with the expendable prototypes. Good idea that...

If Blue Origin manages same, it will be because they had a billionaire space nut backing them. Rare trick - Elon doesn't have the cash to pull off a standing start... in fact, if you consider New Shepard, even Bezos isn't going for a complete standing start...

If Reaction Engines Ltd. manages same, it will be because of Shuttle's technological and knowledge-base legacy, plus decades of patient tech development on their end, especially the focus on the precooler (their frost control technology is actually a very major breakthrough and a world first). And Skylon is the only live proposal I'm aware of that seems (for a number of reasons) to actually have the potential to fulfill Shuttle's initial promise.

You appear to believe that it's somebody's fault your sci-fi dreams didn't materialize, and you've apparently chosen to blame the one organization that tried hardest to make them happen. Sure, in a perfect world, things would have been better. Not likely as good as we all thought in the '60s, but better. Well, it's not a perfect world. Sure, in hindsight we can see a lot of things that could have been done better, even under imperfect circumstances. But the people doing them didn't have the benefit of hindsight.

A quote comes to mind:

Certain things are bad so far as they go, such as pain, and no one, not even a lunatic, calls a tooth-ache good in itself; but a knife which cuts clumsily and with difficulty is called a bad knife, which it certainly is not. It is only not so good as other knives to which men have grown accustomed. ... The coarsest and bluntest knife which ever broke a pencil into pieces instead of sharpening it is a good thing in so far as it is a knife. It would have appeared a miracle in the Stone Age. What we call a bad knife is a good knife not good enough for us; what we call a bad hat is a good hat not good enough for us; what we call bad cookery is good cookery not good enough for us; what we call a bad civilization is a good civilization not good enough for us.

In this case, what we have "grown accustomed" to isn't even real. It's a sci-fi fantasy. People are feeling betrayed because reality didn't measure up to the dream.

Well, it may yet. And if it does, it will be because NASA laid the technological groundwork.

-Shuttle program is canceled
-USA still needs vehicle aloowing space access.
What does this mean?
I think that this mean that Space Shuttle can not answer to requirements.

You're reading too much into it. I don't think you fully understand the degree of stumblebum head-in-the-sand foolishness the U.S. government is capable of.

- Columbia destroyed on reentry. Nation panics.
- Reacting to Columbia, Bush announces Vision for Space Exploration and end of STS in 2010, OSP and SLI lost in the shuffle
- STS stays cancelled because Griffin's hijack of the VSE needs the money
- Griffin's hijack of the VSE goes down in flames; STS stays cancelled because Obama can't be arsed

Result: U.S. domestic manned spaceflight gap, and a mad scramble to plug a serious ISS logistics shortfall. Nothing but a Shuttle extension could have closed the gap by the time The Won took office, certainly not the "commercial" providers.

It is true that Shuttle can't meet the requirements of the VSE. It's a LEO-only vehicle, especially after Challenger's destruction made everyone too scared to put a liquid-fueled stage in the payload bay. So something else is needed to do exploration.

But in terms of LEO capability, Shuttle was unmatched. It could do everything the capsules and expendables can do and more, with one exception: it couldn't provide lifeboat capability for the space station. And the only reason it couldn't do that is the cancellation (for no good reason and in violation of an international agreement) of X-38.

It is also true that Shuttle was intrinsically less safe than a properly-designed vehicle with a LAS, provided the latter has plenty of flight history. But the safety concerns were overblown. Shuttle was safe to fly when flown safely.

[It's also worth noting that Orion (the VSE crew vehicle) can provide lifeboat services, and Orion would have been ahead of schedule and under budget if it weren't for the Ares I...]

[Solids] are again part of the SLS and were part of Constellation, Direct etc. Everyone plans to prop up ATK.

At this point it's a question of expedience. The 5-seg already exists, so let's use it. And apparently internal design refinements are questioning the rush for the Advanced Booster competition...

I'm torn. Chuck's right; the booster replacement is reminiscent of Griffin making it "all about the rocket", which gets in the way of exploration. But it would be so nice to get the solids out and be using big kerolox boosters. Dynetics has a proposal that seems to have scored very highly on NASA internal analyses, involving the resurrection of the F-1A. And Aerojet is going to do combustion stability testing for a large oxidizer-rich staged combustion engine (yes, that's Russian-style rocket technology. These are the guys behind the "AJ-26", after all)...

[GIThruster]

When the airforce got involved, was when all the problems started.
Otherwise they could have built somethig like the Phoenix VTOL, or the other VTOL designs that were discussed at the time.

No. That's not the way it happened and you're not hearing what I'm saying. The completely reusable design had already been shown would be much more expensive, so maintaining it would have been cheaper is just stupid. The various assemblies that were considered, all had the problem that ice shed off the tank would hit the orbiter, so pretending Phoenix was a consideration is stupid. It was never a serous contender. You want to blame Shuttle and pretend it displaced better designs, but those designs were never considered seriously because they were considered too advanced.

Think about how dopey it sounds to have people whine that Shuttle was not advanced enough and that X-33 failed because it was too advanced. People need a reality check. The Shuttle was an excellent craft, especially given it was designed when computers were the size of refrigerators and gyros the size of washing machines.

The whining that Shuttle was compromised by the need to launch large military sats is likewise dopey. Had those sats not needed launching, it's not that we'd have a different shuttle, it's that we would have had no shuttle at all, and likely no ISS either. The thing Shuttle is responsible for more than anything else was that it sold a vision, of routine space access, and it achieved that much.

[Skipjack]

I don't think that's a safe assumption, not if you mean significant safety hazards. Both fatal accidents were the result of ignoring known problems.

Fair point. Still it is not unlikely.

NASA kept trying - Shuttle-II, X-30, VentureStar, the Space Launch Initiative - even now, they're working on various hypersonics and advanced propulsion technologies. Others kept trying too - HOTOL, Delta Clipper, Sänger II, Kistler K-1. This stuff really is hard, as much from a funding perspective as from a technical perspective (not all of the abandoned schemes failed technically).

Yes and they always aimed way to high always the same stupid requirements or it the project was cancelled for mere political reasons not technical reasons (DC-X e.g.).
They could have had a full RLV in the 80ies or earlier if they had listened to Bono. His designs would have worked, but of course they did not have any cross range. Some of the smaller ones also did not have the heavy lifting capabilities that were so important for some reason.

No. That's not the way it happened and you're not hearing what I'm saying.

Yes it is the way it happened, read the links I posted!

[GIThruster]

- Columbia destroyed on reentry. Nation panics.
- Reacting to Columbia, Bush announces Vision for Space Exploration and end of STS in 2010, OSP and SLI lost in the shuffle
- STS stays cancelled because Griffin's hijack of the VSE needs the money
- Griffin's hijack of the VSE goes down in flames; STS stays cancelled because Obama can't be arsed

Result: U.S. domestic manned spaceflight gap, and a mad scramble to plug a serious ISS logistics shortfall. Nothing but a Shuttle extension could have closed the gap by the time The Won took office, certainly not the "commercial" providers.

I realize wiki says that VSE was the reaction to the Columbia Disaster, but I doubt that is a fair appraisal, and much less an observation. I don't recall it coming up in the Aldridge Commission. You can look for reference to that if you like:

http://www.nss.org/resources/library/sp ... Report.pdf

In any event, the gap was assured when X-33 was cancelled. There needed to be a replacement at that time and nothing was offered. When the Alderidge Commission crunched the numbers, they recommended Shuttle be ended because it would become too expensive to extend the program. VSE pointed back to rockets since spaceplanes aren't much use past LEO. The directive was to get out past LEO. That is what killed Shuttle since it could not be run at the same time as the rest of VSE.

You mentioned Griffin "hijacked" VSE twice, but that's not really fair. I know how people love to hate on Griffin, but it was his call. You can't hijack what is your own. NASA engineers love to complain he didn't listen to this group or that group, but no matter what Griffin decided that would have been true anyway. I never liked the Stick, and it was a political solution, but we're not doing any better since. SLS is in many ways worse, and it is going to cost a lot more.

Note too Skippy, it was the Alderidge commission that suggested COTS, so pointing to Obama and pretending he is responsible for CCDev is stupid. He just continued what was working.

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I realize wiki says that VSE was the reaction to the Columbia Disaster

I wasn't using wiki. I was going by memory. It's a very common impression, and I'm sure you can understand why...

You mentioned Griffin "hijacked" VSE twice, but that's not really fair.

Okay, fine, it was Congress who insisted on defenestrating O'Keefe's plan and going with Shuttle-derived; Griffin was their tool. (I can't back that up, BTW...) It was, however, his idea that got selected, because he tweaked the ESAS to get it selected. If leaning on an engineering study to get your own idea picked isn't hijacking, I don't know what is...

I never liked the Stick, and it was a political solution, but we're not doing any better since. SLS is in many ways worse, and it is going to cost a lot more.

I can't think of a single way in which SLS is worse than Ares I. (Besides the original justifications for the Stick, which are irrelevant at best.) Also, it is not going to cost a lot more. Where did you get that idea? It is going to cost less.

We're definitely doing a lot better than we were. The question is whether it's good enough; politics is a fickle mistress...