Posted on 02/01/2003 8:26:17 PM PST by Magnum44
NASA Unlikely to Build New Space Shuttle Sat Feb 1, 6:15 PM ET
By MATT CRENSON, AP National Writer
NASA (news - web sites) is extremely unlikely to build a new space shuttle to replace Columbia, according to experts, leaving the space agency with the three remaining orbiters as its entire fleet for the foreseeable future.
The next generation of reusable space vehicles is at least 10 to 15 years off, said Donald H. Emero, who served as the shuttle's chief engineer from 1989 to 1993.
"I think the country will not invest in any more shuttles," Emero said Saturday.
Until a few years ago, NASA was exploring several designs for vehicles to replace the space shuttle. But NASA's new administrator, Sean O'Keefe, has shelved those designs and committed to operating the space shuttle for the next 10 to 15 years. The fleet's primary mission during that period will be constructing and servicing the international space station (news - web sites).
Discovery, the oldest of NASA's three remaining shuttles, has been in service for 18 years. Endeavour, built at a cost of about $2 billion to replace the Challenger after that spacecraft exploded shortly after takeoff in 1986, has been flying for a decade. Atlantis, the third remaining shuttle, has been in use for 17 years.
NASA's shuttle fleet was grounded for nearly three years following the Challenger disaster, as investigators struggled first to determine what had caused it to explode with seven astronauts on board and then to fix the problem. In the hours after that accident, few could have guessed that the cause would be a rubber "O-ring" — stiffened and cracked by low temperatures.
At that time, NASA had sufficient spare parts to assemble Endeavour as a replacement for Challenger. But today the space agency does not have that capability.
Emero said the investigation of Saturday's accident could take as long as that inquiry, but doubted it would because Challenger was destroyed by such a minor defect that was difficult to find.
There is no doubt that the remaining space shuttles will be grounded for some time pending NASA's investigation of the Columbia accident.
"Certainly there is a hold on future flights until we get ourselves established and understand how this happened," said space shuttle program manager Ron Dittemore.
The next shuttle mission on NASA's flight schedule is a March 1 trip to the space station by the Atlantis orbiter.
During the 1990s, NASA spent billions of dollars investigating a radical design to replace the space shuttle. The X-33 vehicle would have had a dramatic "lifting body" design propelled by a type of rocket that had never been used in spaceflight. But persistent engineering problems led NASA to abandon the vehicle in 2001.
Sure, and I am just talking so for discussion, anything goes. But if I were seriously making decisions, it comes down to cost, schedule, and risk. Of the three, the program killers are cost and risk. An orbital space plane is already risky in terms of technology, and some of its elements are already in test. To my knowledge, the space elevator is only a concept, an article in Popular Science magazine.
Presented with that, and a present need to find a solution, Orbital Space Plane is less cosly and less risky. But even that may be too ambitious. Maybe we should be looking at more conventional options like a man-rated EELV with a command and service module. I know the space plane is sexier, but if its to risky in terms of achievability, what else do we fall back on? The (then) 30 year old shuttle? I don't think so.
Once we get to orbit, we can do all kinds of things. We can build nuclear and ion drives to outer planets. We can build service modules to get between LEO and GEO, or LEO and lunar orbit. But to do any of this, we need RELIABLE, cheap Earth to LEO service. Nowhere in that requirement does it say it has to fly like a plane or be reusable, so all trade space should be open. We should look at it very much like a company looks at its survival in the market. That is find the lowest risk, followed by lowest schedule, followed by lowest cost solution. (Of course, the order of those priorities are subjective. I put them in the order I would choose for this particular effort.)
Goodness knows we need something new in the way of "growth sector" industries now that the computer industry has, er, "matured".
And that in itself is a valid arguement, that it is a vital US interest that a particular industry be healthy and on the leading edge in development. What you would have to do now is substantiate that the growth sector you refer to is indeed vital to our national interest. You've just begun your graduate thesis. Sell your argument right and you could be advising the NSC before you know it.
Regards,
I was 17 when Neil Armstrong took his first step on the moon, and I ditched work (as a dishwasher) long enough to race home and witness it. I remember gazing at the moon in awe that week in July, imagining the adventures to come.
Almost 35 years have passed, and the "adventures" have amounted to a couple robots on Mars, a few camera-equipped satellites zipping through the solar system toward eternity, and the Space Shuttle.
I'm not discounting the accomplishments of the space shuttle program, but I had little doubt in my mind back in 1969 that Star Trek, or something like it, would become a reality in my lifetime.
I guess I'll just have to get over it.
It looks now that Russians will get money.
Alas.
I think we need to question the role of humans in space. In my opinion after 28 years in the business, we should not risk human lives for any tasks that can be done robotically or tele-operated. Only tasks that demand human presence should be assigned to humans. What tasks are they? Going to Mars or the Moon is about all I can think of, and we will not be doing either in my lifetime. I'm about used up.
Build a space elevator. It might take 50 years and $500 billion. But it will pay off big, and the safety will be much better. After that, you get humankind exploding into the Solar System, the return of rockets and exploration, etc.
Nothing else will do that.
(There are concepts, like Orion and NERVA, which might serve the same purpose but which are DOA due to hysteria.)
I used to hold as a matter of faith that humans would escape Earth. Now I am not so sure. As I said to Marc Millis, riffing on the Fermi Paradox, "If any of these schemes were feasible, intelligent ETs would have reduced them to practice a million years ago. We do not observe their traffic or delegations landing on the White House lawn to meet the interns. Hence either there are no intelligent ETs or none of these schemes is feasible."
Do you know how hard it is for me to say these things? I've devoted my life to getting humanity off this rock, and when they bury me, they'll put a picture of Sisyphus on my gravestone.
Abortion plays a role (~ 40 millions) in making immigration necessary.
You look at human space travel only from the tech/science perspective. As I have said here, for better or worse, the space program is also a political tool. You don't inspire millions of kids into fields of science by robot missions, you do that with astronauts. You don't build the infrastructure to return to the moon or a mission to mars with robots, you do it from a manned space station.
You can disagree with me and that would be an argument I don't care to debate. It's too philosophical for me. What I will do is believe that man has a place on the frontier, and that it is in our national interest to lead that. And all of my previous arguments have been to debate how best to keep that effort alive.
Finally, I won't poo-poo on the space elevator, but I personally believe it will never amount to anything more than a paper concept. And while some would argue that if you don't fund it, it will never have its chance, I would reply that history is filled with examples of pooring resources down bad ideas. Elevator is a pipe dream IMO. But what do I know.
Regards,
The problem is that the public never embraced space as a popular thing after NASA folded its Apollo tent. It was understood as a stunt--we beat the Russians, game over, let's go home.
I saw a quote somewhere, some idiot said, "Why do we need the Space Station and NASA when we have Star Trek?"
Another article stated that space is now considered routine, non-cool. Computers, internet, and software are now the big deal. Or so said this pundit.
Elect me President. I'll announce an increase in NASA's budget to $100 million a year, to be taken out of the hide of HUD and eliminating the Dept. of (mis)Education. I'd be impeached in a day, if they didn't lynch me first.
--Boris
I know I did. And seems many others here did too. Its the media and the welfare/redistribution lobby that look at NASA as a stunt, but remember, they look at the military as a waste of money, too. You can't allow yourself to be brainwashed by that crowd.
And I'd vote for a candidate if he promised to eliminate HUD, all other trhings being equal. :^)
Shh.
Lemme tell ya. Aerospikes are bad medicine. Why?
1. They are heavier than equivalent conventional nozzles.
2. They have worse performance than conventional nozzles.
3. They are difficult to cool.
I almost lost my job saying these things but nobody could refute them.
They are heavy because you have a smaller "throat" which must be held to very high tolerances under pressure; this makes heavy structures.
They have worse performance because the shear and turbulence losses of the outside plume reduce performance. Yes, they are "altitude compensating" but so would be an extendible nozzle.
They are difficult to cool. Not sure why; one of my colleagues worked the heat-transfer issue and told me that. I suspect it is because you must cool a greater area with the same flowrate of fuel.
There are numerous alternate nozzle shapes, such as E-D (Expansion-deflection), annular, dual throat, linear aerospike, round aerospike, conventional spike, etc. Most of them have been looked at; so far nothing beats a good old Rao optimum.
Incidentally, Russian engines use nozzle shapes that are much different from ours. This has always puzzled me; the laws of fluid dynamics are the same. Our nozzles are "voluptuous", usually 80% truncated Rao optimum. Russian nozzles look "flatter"--more like cones.
Intuitively a cone or near-cone would be worse than one designed by MOC. HOWEVER, in studies of a solar rocket, we used optimization S/W with CFD and came up with something very similar to a Russian nozzle shape. That program was snuffed also.
When I studied Russian engines for a living (before perestroika/glasnost) I concluded that the Russian combustors were crummy but the nozzles better than ours. In other words, we are superior combustion engineers; they are superior aerodynamicists. We take our losses in the nozzle (usually embedded shocks?) and they take them in the combustor. I wondered what would happen if you put an American combustor on a Russian nozzle. I believe this was being tried but Clinton's minions killed it, I think.
--Boris
True too true!
The lack of testing is exactly how the hubble got screwed up. No one wanted to pay for testing the Unit as whole. The mirror tested out perfectly. Unfortunately it was tested to the wrong specs.
No one wants to believe that this stuff is just about the most important research that can be done. Why? Because no other nation can do it and if we stop we'll be no better than the rest. Come to think of it, that's problably why Libs hate this stuff, along with their not being good at math (eg Hillary Clinton).
Ah, but great and wonderful things have been accomplished since then. Yeah, I remember thinking there would be "moon stations" where we would go to vacation some day, but attention was turned elsewhere. It is so vast out there that no matter how fast we progress it will just be touched around the edges in one lifetime, or ten.
A lot of the pressure to advance was lost when the USSR collapsed. Perhaps with China breathing down our necks we'll once again feel the competitive heat.
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