I decided to start a new post based on comments at this one, in which in response to a comment of mine, a commenter writes:
“Escape systems can actually introduce more risk than they remove, and not be worth their cost and weight. There is a reason that airline passengers aren’t issued parachutes.”
This is a rather alarming line of reasoning, the kind that led to seven dead astronauts in 1986. Of course any crewed spacecraft requires some kind of launch escape system. If Challenger didn’t prove that, nothing will.
If so, then nothing will, because Challenger proves nothing of the kind. But once again, this is the fallacy of hasty generalization. Challenger, and the Shuttle in general, don’t “prove” anything about launch systems in general, either expendable or reusable — it’s simply unreasonable to draw huge extrapolations from a single example.
One of the main reasons for abandoning the Space Shuttle is the lack of a launch escape system. Otherwise, why give up such a massively capable vehicle in favor of a 1960s throwback capsule?
There were a number of reasons to give up the Shuttle, and the lack of an escape system was one of the weaker ones. It was costing too much to operate, and becoming untenable to continue to operate it with only three vehicles left in the fleet. Each flight is costing us in excess of a billion dollars now, and if (as some fantasize) the program is extended, at an even lower flight rate, they will cost much more. And each flight risks losing another vehicle, and if that happens, continuing to operate it is simply infeasible. Cold-hearted as it sounds, we have a lot of astronauts, but we have only three orbiters, and the cost of replacing them is far beyond what it would be worth.
There was nothing intrinsically wrong with the basic philosophy behind the Shuttle — that the cost of an escape system, in dollars and weight, would exceed its value. The failure was in not making the vehicle as reliable as intended.
Now could the Shuttle have been made that reliable? Probably not, in the first attempt. But then, the first attempt should have been a much less ambitious system, and there should have been evolution and lessons learned from it. In a sense, Shuttle was a bridge too far, as Apollo was — a huge government program that became a self-fulfilling prophecy that we could afford only one.
Can any launch system, with today’s knowledge, be made sufficiently reliable as to not need an escape system? I think that a reusable one probably can. Recall that both Challenger and Columbia were lost as a result of expendable components. Can an expendable vehicle be made that safe? That’s more problematic, because no matter how good your quality control, every launch of an expendable is a first launch. So it may well be, depending on what level of safety you demand, that you’ll need an escape system as a backup.
You will probably always be able to find people who will ride a rocket into space whatever the risk, but if crew losses start to mount, and the public perceives that safety concerns are being overridden by bean counters, the sources of funding for manned space travel, public and private, will quickly dry up. If the Challenger and Columbia disasters had happened, say, four years apart instead of 17, U.S. manned space flight would have likely ended then and there.
That’s an interesting counterfactual, but there’s no way to know that. Many always postulate that the next disaster will kill human spaceflight, just as they claim that a single death of a passenger will kill the space tourism industry. Such claims are made in defiance of history and human nature. We killed lots of people in aviation, and still occasionally do, but the industry survives.
I know space flight will always be risky (and hence never remotely as safe as airline travel) and that overemphasizing safety will kill exploration beyond LEO, but you have to provide some kind of escape option during the most risky phase of any mission– the launch. I’m sure Elon Musk understands this and has no plan of putting crew into a Dragon capsule without an escape option.
I don’t know what Elon understands and plans, and you may be correct, but I think that it would be driven by the customer. For instance, if I were buying rides from him, I might say “…skip the escape system — I need the payload, and don’t want to take the risk (for example) of it not separating properly. I have insurance policies for my crew.” If NASA insists on an escape system, it will likely be a political decision, not necessarily one dictated by a rational probabilistic risk analysis (I’ve never seen the PRA for the Orion LAS). I know that when I was doing hazard analysis during Phase II, it wasn’t even a question we were supposed to ask — that Orion would have an escape system, was a given. But an escape system introduces a lot of new hazards into the launch, many of which can bite you on an otherwise nominal mission (e.g., failure to separate). I know that the bureaucrats are afraid of being called before Congress and having to testify that they killed astronauts because they didn’t have an escape system. But they never consider the possibility that they might be called up on the Hill to explain how they killed them only because they did. And it’s not an impossibility.
In any event, if NASA insists on an escape system, it will be a decision implicitly premised on the belief that what we are doing in space isn’t important, otherwise we’d be willing to risk crew on it. If Shuttle proved anything, it is that safety is not a binary condition, and no matter how many billions we spend in an attempt to never lose an astronaut, we’re still unlikely to be successful, particularly with a government program. So we might as well just accept the risk, and do a lot more at less cost.
[Update a few minutes later]
One more point. Several space passenger vehicles are under development, including SpaceShipTwo, Lynx, and whatever Armadillo and Masten are planning. We know that the first two don’t have a crew escape system — they are designing for reliability (actually, I only know that’s true for SS2, I’m not sure about Lynx). Armadillo and Masten may have plans, but I’m not aware.
Yes, they don’t go to orbit, but there’s nothing magic about that. There is no bright energy line on which one side an escape system is required, and on the other it is not. Every vehicle is designed to meet its requirements, one of which is some level of safety, but if too much is spent (in either dollars or weight), the vehicle design or business case may not close, and you may not even get more safety for your dollars. Fortunately, we now have a number of competing designs and can let the market sort it out, rather than a dictate from on high by the kind of idiocy represented by the ASAP.
[Update a couple minutes later]
One more. I would dispute that launch is the riskiest part of the mission. I think that Columbia is a rejoinder to that. When you look at the total risk of a lunar mission, it’s a misallocation of resources and a defiance of rational systems engineering to put so much of them into reducing the risk of launch. But misallocating resources is what a politically driven institution does.
[Another update a while later]
OK, yet another point. I wrote: There was nothing intrinsically wrong with the basic philosophy behind the Shuttle — that the cost of an escape system, in dollars and weight, would exceed its value. The failure was in not making the vehicle as reliable as intended.
I’ve made this point before, many times over the years, but it bears repeating, particularly for new readers here. Shuttle wasn’t just insufficiently reliable to carry crew without an escape system — it was insufficiently reliable, period. This is because, as I said, we have a glut of people willing to fly into space, and a shortage of vehicles with which to do so.
Any reusable vehicle must be highly reliable, regardless of whether it carries crew or not, or it becomes unaffordable (as the Shuttle did). This is why the notion of “human rating” a reusable launcher is nonsensical. It is the value, and replacement cost, of the vehicle itself that drives the reliability, not its payload, whether human or otherwise. It’s also the reason that it makes no sense to put a crew escape system in one (again, the decision to not have one in the Shuttle was the correct one). If your reusable vehicle is so unreliable that an escape system is required, it is unaffordable to operate, period.
Rand,
Two quick thoughts:
1-FWIW, Masten isn’t currently working on any manned vehicles. We may go that route down the road, but all of our vehicles are unmanned for now.
2-Regarding your last update (about obsessive crew safety being a misallocation of resources), I full-heartedly agree. The crew safety of one of those “oh-so-scary, death-trap, EELVs” using NASA’s numbers only changes the odds of losing a crew on a lunar mission by a tiny percent (I can’t recall the exact number, but it was like going from a 1/62 to a 1/60 chance of failure. Most of the risk of losing a crew have to do with the lunar landing, surface ops, return, and reentry. That is where the money would be spent if politicians a) really cared about safety, b) had any understanding of math and statistics, and c) actually thought we’d ever be going back to the Moon.
~Jon
I think that part of the “reasoning” behind having the launch escape systems is also historical. Our view of what a rocket should be was formed by a whole bunch of them exploding on the pad. That left a mark, and I suspect that tradition accounts for a lot.
I don’t know what Elon understands and plans, and you may be correct, but I think that it would be driven by the customer
SpaceX has definitely been planning on an escape system from the start — and is definitely responsive to their customers.
I was at an FAA meeting about five years ago where Frank Sietzen (their Washington rep at the time) ranted about how capsules should have no flight controls, only a single button to activate the escape system. Shades of the original “Mercury” capsule. Now that they’re dealing with astronauts who have actual flight experience, their plans have changed and they’re putting in real flight controls.
They might have saved some time if they read The Right Stuff at the beginning.
One more point. Several space passenger vehicles are under development, including SpaceShipTwo, Lynx, and whatever Armadillo and Masten are planning. We know that the first two don’t have a crew escape system — they are designing for reliability (actually, I only know that’s true for SS2, I’m not sure about Lynx).
Lynx will have ejection seats, unless plans have changed without my knowledge.
They intend to use ejection seats the same way military aircraft use them, however — as a last resort. There is no thought that ejection should be a first resort or that it makes systems safety and reliability irrelevant.
I know space flight will always be risky (and hence never remotely as safe as airline travel
Note — people made similar statements about jet engines, when they first came out.
Lynx has the same crew bailout concept that the EZ-Rocket and X-Racer have. That includes parachutes and the ability to open the door and jump out. A major factor in the military use of ejection seats is to clear the vertical tail; a problem the Lynx doesn’t have because the tails are outboard. We are evaluating the use of a seat pusher to assist egress, but that’s not really an “ejection seat” per the traditional definition.
The ability to land at less than 100 Knots without power is a significant safety feature, as are the four independent engines (each with a containment shield), two independent main propellant feed systems, and ability to abort the takeoff roll. Of course, as Rand points out, the big safety feature is the design for thousands of flights per vehicle with no engine change between flights. Incremental flight test, no common bulkheads, no monopropellants, dual independent electrical power sources, etc…….etc…..
To what extent are the Orion capsules intended to be reusable? How many of them supposedly will be built? And … assuming NASA eventually does build and launch Orion capsules, does anyone have a realistic (i.e., cynical) estimate of how many actually will be built and how often any one capsule will fly?
To what extent are the Orion capsules intended to be reusable?
My understanding is that, even after all these years, that remains an open trade (partly because they continue to vacillate between water and land landing).
It’s all part of the economic insanity in the way that NASA does human spaceflight, and has since Apollo.
Recall that both Challenger and Columbia were lost as a result of expendable components.
I thought Columbia was lost due to an impact into a reusable reinforced carbon carbon leading edge in a wing. That would make one vehicle lost due to reusable components.
AFAIK there was only one Soyuz lost to depressurization, but they considered it important enough to add the Sokol suits for every flight ever since at considerable cost. From what I understand the suits are also useless for anything but emergencies, and use considerable space. I see no problem in adding these and the escape tower if it makes people more confident in the system.
The Soyuz has reentry rockets. If it did not have a separate orbital module on top, couldn’t you use those for escape during launch? Or is the performance too lousy?
Capsules should absolutely be reusable. However, NASA has apparently told SpaceX that they can’t reuse the Dragon for a second or third mission to ISS.
Typical.
Not quite Crew Escape, but any thoughts on the latest Space Cannon variant?
Cargo only, mostly submerged.
I thought Columbia was lost due to an impact into a reusable reinforced carbon carbon leading edge in a wing. That would make one vehicle lost due to reusable components.
Columbia was lost because the reusable part was struck by a piece of an expendable part, and that reusable part was not designed for such a strike, any more than it would have been for an orbital debris strike. The reusable part performed to specs.
It’s just as ridiculous to say that it was lost due to the orbiter as it is to say that the plane went down in the Hudson due to bad design because it couldn’t handle bird strikes in both engines simultaneously. There are some things that you can’t, or shouldn’t have to design for.
” Gary C Hudson Says:
January 22nd, 2010 at 6:59 pm
Capsules should absolutely be reusable. However, NASA has apparently told SpaceX that they can’t reuse the Dragon for a second or third mission to ISS.
Typical.”
Hopefully Gary,
Robert Bigelow will be more open to a slightly used Dragon, only driven to the ISS on sundays by a little old lady for Pasadena.
“Robert Bigelow will be more open to a slightly used Dragon, only driven to the ISS on sundays by a little old lady for Pasadena.”
Indeed. I also understand that they will recycle them into DragonLabs.
Sometimes I think the mania for preventing all risks is another symptom of the infantilization of our society.
“Our view of what a rocket should be was formed by a whole bunch of them exploding on the pad. That left a mark, and I suspect that tradition accounts for a lot.”
Indeed. And even so, out of all manned space flights to date, on only one occasion has an LES actually (and in this case, successfully) been used:
http://www.youtube.com/watch?v=UyFF4cpMVag
Another Soyuz flight had a mission abort due to a staging problem, but simply descended/landed normally and suborbitally downrange. (with the crew requiring multiple reassurances from the ground that they would not come down in China, I’ve heard)
And of course, in both cases, an expendable launcher.was involved.
“However, NASA has apparently told SpaceX that they can’t reuse the Dragon for a second or third mission to ISS.”
So, is their attitude; “If we aren’t doing some degree of transport re-useability, we trust no one else, when supporting our operations, to do so either?”
Hmm…
Nothing keeps SpaceX from reusing Dragons that never get used for NASA work. Eventually, if they survive long enough and become reliable, reusable Dragons will have a record good enough to convince NASA to reuse them.
There are only certain points in a flight where a crew escape mechanism makes sense: right on the pad, where you want to “punch out” from an exploding rocket motor and during final approach where a parachute would do you some good. Anywhere else you might as well either stay with the vehicle or, if it’s breaking up, step out into space and hope for rescue before your orbit decays. Both Challenger and Columbia broke up at the worst possible moments: crew escape devices would have been useless.
>To what extent are the Orion capsules intended to be reusable?..
When I was on the program in ’08 they decided they would be fully expended after each flights. I spent some time rewriting service life requirements down from 10 flights to 1 flight worth.
> … There were a number of reasons to give up the Shuttle, ==
> ==. It was costing too much to operate..
Ah, the shuttle cost a fraction as much to operate then Ares/Orion is expected to. It also cost far less to develop then Ares-1/Orion alone.
Even in the cost metrics Ares/Orion/Altair don’t measure up.
If your reusable vehicle is so unreliable that an escape system is required, it is unaffordable to operate, period.
Wouldn’t a system that’s only reusable 10 times already be a huge improvement over what we have today? If so, I can see why you might want escape systems.
Wouldn’t a system that’s only reusable 10 times already be a huge improvement over what we have today?
In theory, though I’ve never quite understood what environmental or design features would allow a system to be reused ten times, but not a hundred or a thousand. Engine? Replace (or more likely rebuild) the engine. TPS? Replace the TPS (and make it both modular and simple to do so). But throw the entire system away after only ten flights? Why?
Maybe it’s not necessary to have an intermediate step of very limited reusability. I don’t remember where I got that idea. I was thinking of early maintenance-free reusable lunar landers, but maybe it doesn’t apply to those either.
Maybe it’s not necessary to have an intermediate step of very limited reusability.
Well, actually, that does seem to be Elon’s approach (at least in theory). We’ll see if and how it works out.
The proper sort of evolution, as Jeff Greason has long noted, isn’t starting with an orbital vehicle and attempting to make it gradually reusable, but to make a reusable vehicle (or system), and expand its performance envelope to orbit. We could have been doing a lot along these lines for decades, but at least the private companies have finally gotten started.
This appears to be the only reliable way to do it, although I worry I may not live to see the orbital version. If only NASA would get out of the launch business things would go so much faster without any cost to exploration, even with TRL 9 technologies only. There are no technical obstacles, just political ones. One very interesting third approach would be Jon’s recent proposal if it manages to go beyond LEO before NASA does. That would tackle the political problem head on, because then the statement (lie actually) that only NASA can do the more difficult stuff beyond LEO would be disproved beyond a shadow of a doubt.
In theory, though I’ve never quite understood what environmental or design features would allow a system to be reused ten times, but not a hundred or a thousand. Engine? Replace (or more likely rebuild) the engine. TPS? Replace the TPS (and make it both modular and simple to do so). But throw the entire system away after only ten flights? Why?
Two problems that I see.
First, there’s the landing mode. Parachute recovery is not robust. Military paradrops expect to lose a certain percentage of equipment. The Canadian military once tried dropping a bulldozer. They never tried it again because they broke the bulldozer. Soyuz capsules frequently land on their side (which is not by design), have been known to roll down hills, etc. X-38 had a lot of hard landings when NASA was doing drop tests — note how many copies they built for those drop tests. Water landing is not a big improvement. The gee shock is still high, and search and rescue operations at sea are neither cheap nor easy. Even with GPS, SpaceX has had trouble finding stages that were dropped at sea.
Aircraft escape capsules have never been reusable (of course). Even the Russian TKS capsule, which was meant to be reusable, is designed for only 7 flights (or so I was told by one of their salesmen, several years ago).
Second, there’s the production-line problem. NASA was counting on about 2 lunar missions per year. If they did that for the next 20 years, and the capsule was designed for 10 or more flights, they would need, what 4 or 5 capsules? Similar to the number of Shuttle orbiters they built. But then, what happens if they lose one or decide to expand the program?
I’m sure NASA didn’t want to get into that situation again. But to keep the assembly line open, you need to keep building capsules at a low rate. At least one or two a year, if you want every technician to practice all the steps in his job once or twice a year.
So, they’re in a catch 22 situation. They can shut down the assembly line and risk running into the same problems they did with Shuttle, or they can keep building capsules, in which case they don’t have enough flights to use them more than once. It’s hard to see any other solution, within the constraints of the program as NASA defined it.
We were discussing sane programs, designed for affordable access, not ones within NASA’s arbitrarily definitional constraints.
Is XCOR mistaken in adding ejection seats? At the very least they might help with sales, which seems like a perfectly good reason. Fighter jets also have ejection seats, but small aircraft don’t. Is that because the only reason a fighter jet has ejection seats is for situations where the enemy shoots off bits of your aircraft? Are there known cases where ejection seats saved a pilot’s life other than in combat or simulated combat? I would suspect there are.
This appears to be the only reliable way to do it, although I worry I may not live to see the orbital version.
That’s the problem, Martjn. A lot of space buffs are afraid they will not live long enough to get into orbit (or walk on the Moon, or Mars, or wherever it is they want to go). So, they call for a Von Braunian Giant Leap (Moon Rush, Mars Direct, etc.) because incremental development will slow things down.
The reality of course, is very different. NASA has tried the Von Braun approach for the last 50 years, and where has it gotten them? Contrast our progress in space during that half century to the progress aviation made during 1903-1953, using the “incremental approach.”
And no, before someone says it, the rapid progress in aviation was not due solely to the World Wars. Over 14,000 people had flown in airplanes before World War I — more than the space program accomplished in 50 years (and remember that while aviation had the two World Wars, the space program had all the missile spending during the Cold War to give it a boost).
One very interesting third approach would be Jon’s recent proposal if it manages to go beyond LEO before NASA does. That would tackle the political problem head on, because then the statement (lie actually) that only NASA can do the more difficult stuff beyond LEO would be disproved beyond a shadow of a doubt.
I’m not sure what Jon proposed, but DoD and private enterprise have more recent experience beyond LEO than NASA does. Count the number of military and commercial satellites in GEO. None of them were placed there by NASA. NASA doesn’t even have a launch vehicle that’s capable of missions beyond LEO — it hasn’t for years. The fact that politicians think only NASA can do that is mind-boggling.
Fighter jets also have ejection seats, but small aircraft don’t. Is that because the only reason a fighter jet has ejection seats is for situations where the enemy shoots off bits of your aircraft?
No, ejection seats are also useful in other situations, especially in single-engine aircraft with high engine-out sink rates. But even in those cases, ejection is generally not the first resort. (Exception: The Russian VTOL Forger has an automatic ejection seat, and the pilot sits braced for ejection at takeoff. But that is not an aircraft any sane person would wish to fly.) Mike Griffin’s statement that vehicle reliability didn’t matter if the capsule had an escape system was truly frightening.
Another Soyuz flight had a mission abort due to a staging problem, but simply descended/landed normally and suborbitally downrange.
Not “normally.” Two near fatalities (the capsule rolled down on a hill and almost fell off a cliff, until the parachutes happened to snag in some trees) and career-ending injuries for one of the crew.
Somebody ought to point out that NASA has flown 6 manned launches without any LES. They were the lunar module takeoffs from the Moon.
As for ejection seats and single engine jets, many years ago I had the opportunity to fly quite few times in the Macchi MB326H jet trainer. The use of the ejection seat was briefed before every takeoff. Still on the ground below 90 knots – we take the runway barrier. Once off the ground and below 180 knots we eject. Once above 180 knots we have enough energy to abort to another runway. So there was a considerable part of the “launch profile”during which ejection was a first resort.
Are there known cases where ejection seats saved a pilot’s life other than in combat or simulated combat?
http://www.youtube.com/watch?v=YL1FblthxQ0
http://www.economicexpert.com/a/Mikoyan:Gurevich:MiG:25.htm
“The speed record for fastest successful ejection at 2.67 Mach is held by a KM-1 equipped MiG-25.” (Obviously, not during combat.)
Ejection seats are also useful in flight test…
So there was a considerable part of the “launch profile”during which ejection was a first resort.
Just because you were briefed on the ejection seats does not mean Macchi considered ejection the first resort and made no attempt to develop reliable engines. If the president of Macchi said aircraft reliability didn’t matter (as Mike Griffin did), do you think anyone would have bought his airplanes, regardless of ejection seats?
I have no idea what Macchi thought but the RAAF considered that in the event of an engine failure after takeoff below 180 knots ejection was *the* option.
We are talking about options in the event of something going wrong after all, not routine nominal operations.
Make the chances of something going catastrophically wrong low enough (you will really find this out only by operational experience) and it is a good bet not to have an escape system for that possibility. It is done every day in private, commercial and some parts of military aviation where the chances of structural or primary control systems failure are remote but lesser possibilities such as engine failures are covered in pilot training. In single engined aircraft an engine failure generally results in a forced landing. There’s a reason why FAR 23 certified single engined light aircraft have a 61 knot maximum stall speed in landing configuration – to give the pilot and passengers a reasonable chance of survival in the forced landing.
Today, quite a few private planes have parachute systems that lower the entire plane to the ground. All Cirrus planes have then as well as many Light Sport Aircraft (LSAs) like the Cessna 162. In actual use, sometimes they work, sometimes they don’t. All of these systems have an envelop for proper functioning. Too fast or too low & slow, you’re out of luck. Still, there have been some lives saved by having the option available.
For space systems, you have to consider the costs, weight and added risks a LES system brings to the equation as opposed to the perceived benefits. The broader you make the LES envelop, the heavier and more expensive it becomes. It’s quite possible the risks caused by the additional failure modes inherent to an LES system could be greater than the risks of a launch failure.
Are there known cases where ejection seats saved a pilot’s life other than in combat or simulated combat?
A friend of mine, Terry Kryway, ejected from the deck of a carrier back in the Sixties. He was bringing his F-4 in for a landing, and the nose wheel gave way when he touched down. (Not his fault — I believe the cause was metal fatigue.) Had he not punched out, he would have been in a very bad way when the aircraft slid off the deck into the ocean two seconds later.
There’s a video of this incident somewhere on YouTube. I’d give a link, but I don’t have Flash enabled on the laptop that I’m using.
Terry Kryway ejects
F8U Pilot Ltjg. Terry Kryway, VF-11 ejects while his plane goes into the water during a landing aboard the USS Franklin D Roosevelt CVA-42 in 1961.
That’s isn’t an F4, but still amazing Mike.
Oh, and Mike – there’s a beta of YouTube via HTML5 – which means Flash-free. There are still other issues.
Al, thanks for the correction and the link!
Regarding Flash, I have it on my other machines. I’m writing this on my “throwaway” laptop, a Dell Latitude CPx (vintage 2000) running Ubuntu that I picked up for $50 as surplus … I won’t be heartbroken if it’s stolen or it dies on the road, and I don’t put a lot of effort into maintaining it. (And the keyboard skips and stutters, and two weeks ago the screen developed a column of stuck pixels, and every few minutes the trackpad freezes up for 30 seconds or so … I really won’t miss it when it dies!)
> Edward Wright Says:
> January 23rd, 2010 at 1:05 pm
> = So, they call for a Von Braunian Giant Leap (Moon Rush, Mars
> = Direct, etc.) because incremental development will slow things down.
>
> The reality of course, is very different. NASA has tried the Von Braun
> approach for the last 50 years, and where has it gotten them?
> Contrast our progress in space during that half century to the
> progress aviation made during 1903-1953, using the “incremental
> approach.”
>
I think your logic’s a bit off here. NASA tried one big leap in the ’60’s, then tried (half tried) the shuttle (which really was back to the designs incrementally developed over from the “40’s – ’60’s. In one sence Shuttle was very successful, lowering cost, increasing capacity, and forming the bulk of all human space flight carrying about half of all cargo ever lifted and 2/3rds of all the people. But it ran out of (or was run out of) commercial market, and the political demands were for more cost per flight.
> == the rapid progress in aviation was not due solely to the World
> Wars. Over 14,000 people had flown in airplanes before World War I
> — more than the space program accomplished in 50 years ==
>
That’s the real reason for the rapid advance in Aviation. 14,000 people in about the first 10 years after the first maned flight? Followed by heavy demand for everything from airliners to fighters to bombers to air-sea rescue, etc etc. With such a huge demand there was a lot of money and competition to push the development of better craft and bigger markets. About the only really big market ever developed for LVs were the ICBMs, and since they could easily be adapted to be orbital LV’s – damn near no sensable launcher was ever developed. So the shuttles, a half thought out aircrfat developed by committee, was the dominant space craft of the first half century of space flight.
A lot of space buffs are afraid they will not live long enough to get into orbit (or walk on the Moon, or Mars, or wherever it is they want to go). So, they call for a Von Braunian Giant Leap (Moon Rush, Mars Direct, etc.) because incremental development will slow things down.
So true. Government is unlikely to get us anywhere, so whatever incremental path is chosen will have to be profitable from the start. This is why starting with suborbital rides and then upgrading to orbital tourism is a good approach. The suborbital rides and orbital tourism would gradually lower cost to orbit which would then allow affordable exploration. Commercial and crew first, propellant and exploration later.
However, if the government is planning is to do exploration anyway, then the enormous demand for propellant in orbit could be harnessed to accelerate things. Buying propellant in orbit could make orbital launches profitable from the beginning. The exploration program would then drive cost down which would enable orbital tourism. Government exploration and commercial propellant launches first, commercial and crew later.
And there’s no reason not to work the problem from both sides.
In any event, once we have affordable LEO tourism, the battle will have been won. Whatever NASA does will no longer be crucial to commercial development of space.
But we’re getting away from crew escape systems…
> Martijn Meijering Says:
> January 24th, 2010 at 8:43 am
>
> == However, if the government is planning is to do exploration anyway,
> then the enormous demand for propellant in orbit could be harnessed
> to accelerate things. Buying propellant in orbit could make orbital
> launches profitable from the beginning. The exploration program would
> then drive cost down which would enable orbital tourism. Government
> exploration and commercial propellant launches first, commercial and
> crew later. ==
>
That benefits space industry, but hurts NASA and the govs interests since it lowers costs a lot, and cuts spending in the right districts.
Hell, if your going to push that, why not contract for commercials to deliver the crews to the moon. Its obviously well within the capabilities of the major areo firms, who could do it for a laughably small fraction of the Ares/Orion/Altair $100 billion development budget, or quarter trillion $ program budget. You could even levarage the bids toward implementing a CATS system with margin cost per pound to orbit well bellow $100 a pound with old reliable tech. But then what political support would the program or NASA have?.
I have no idea what Macchi thought but the RAAF considered that in the event of an engine failure after takeoff below 180 knots ejection was *the* option.
You’re missing the point. Ejection might be the only option once the engine has failed, but there are a large number of safeguards, checks, procedures, failsafes, and backup systems to make sure an engine *doesn’t* fail. Both pilots and mechanics perform steps to make sure the engine is functioning properly before takeoff, and I’m sure the RAF would not be happy if they lost an airframe because a pilot or mechanic skipped those steps — even if the pilot successfully ejected.
That’s a far cry from the EELV philosophy that *expects* a pilot to eject and a total airframe loss on every flight.
I think your logic’s a bit off here. NASA tried one big leap in the ’60’s, then tried (half tried) the shuttle (which really was back to the designs incrementally developed over from the “40’s – ’60’s.
There was nothing incremental about Shuttle development. A huge vehicle, 65,000-pound payload, right out of the box — and it had to go Mach 25 to boot. Add to that, Von Braun style “all up” testing on the first launch. Sure, there were a few glide tests but no rocket-powered flights until then. Remember the subscale supersonic and hypersonic test vehicles Milt Thompson wanted NASA to build? Of course not, they were never built.
> Edward Wright Says:
> January 24th, 2010 at 4:49 pm
>
>
> There was nothing incremental about Shuttle development. A huge
> vehicle, 65,000-pound payload, right out of the box — and it had to
> go Mach 25 to boot.==
>
? All LV’s have to go to Mach 25. 65,000 lb wasn’t exactly pushing state of the art for LVs or aircraft. The aero and systems wouldn’t be simpler or cheaper on a smaller craft (hell, both the Apollo and Orion CM/SM’s cost a big chunk more to develop then the orbiters).
>== Add to that, Von Braun style “all up” testing on the first launch. ==
>
Yeah, that was stupid. Its part of NASA “manage for success”, where you don’t test it until you test it all. EXTREAMLY stupid. First test of the SSMEs was a full up. etc.
The increment they thought would be done on shuttle was to upgrade hte first config. Phase out the SRBs, the ETs – rework the orbiters for better maintainability – replace the crappy TPS.
Sadly the most popular thing about the orbiters was the unnecessary labor hours to support it.
OH! now I see what you mean about the orbiter going to Mach 25. Previous rocket planes hadn’t flown that fast. Though I think after the work done on the Dyna soar they were pretty confident on the aero performance.
There seems to be a systemic misunderstanding by the lay public (which includes reporters) regarding the thrust-oscillation issue, and JimMcDade alluded to it. The low-frequency TO problem occurs very late in an SRM’s burn, not at lift-off, and at a frequency which is too low for electronics to be affected. The FTS is unimportant at this point in the trajectory. Lift-off noise, at frequencies which can indeed damage electronic components, is a totally different issue and is much more easily dealt with.