Space Shuttle

[gtvc]

How do you feel now that the Space shuttle is retired? sad? do you see the program as a failure? I feel sad I used to see the space shuttle as the future an was supposed to be the DC-3 of space.

[PhantomWolf]

It was sad that it never lived up to the potential and hype, it is sadder that the current US space program is now rather directionless.

[Apollo Gnomon]

The original specs for the Space Transportation System included several different vehicles, plus a space station. Instead, Congress/Nixon authorized NASA to build a single vehicle and attempt to use is as the truck, bus and space station all in one.

Like most one-size-fits-all solutions, the Shuttle was a poor fit but looked okay at a distance.

I'm frankly glad the Shuttle has been discontinued as it forces development of a replacement launch system. It had it's time but that time is over.

NASA managed to use the Shuttle well in spite of the intrinsic limitations, but it was too expensive, too fragile and prevented other developments.

[Halcyon Dayz, FCD]

Operational costs were so high compared to what it could deliver that it held back manned space travel.

*Sigh* The roads not taken.

[raven]

An amazing vehicle, too ahead of its time to be really practical. It also, alas tried to be too many things at once. It's going to be a long time before a manned vehicle is practical as a cargo vessel. Still, it enabled astronauts to fix and extend the lifespan and capabilities of Hubble, so it definitely gets my vote as a Good Thing.
Though if anything is the DC-3 of space, it is Soyuz, both launcher, based on the very first ICBM, and the spacecraft in all its iterations.

[gtvc]

My favorite is the Discovery because after The Challenger and Columbia disasters was always the one giving hope and a new start to the program.

I remember the years between Apollo and the Shuttle Nasa didn´t have any rocket to take astronauts to space, I watch in you tube the new capsule Orion landing tests and looks like a new Apollo.

[ka9q]

I also think the Shuttle program was a bad move that set back NASA for decades.

During Apollo, everybody correctly understood that the cash river from Congress was not going to continue after the moon landings. They needed to make space flight more affordable, more sustainable somehow.

But in a classic example of "groupthink", everybody got it into their heads that lowering mission costs meant "reusable launch vehicle". Meanwhile, the guys (they were all guys then) who actually flew these things grumbled about returning to earth as spam in a can. Real pilots don't land under parachutes. Real pilots land on a runway with their hands on the control stick, exhibiting their skills for all to see!

So we got the Shuttle. Despite budget cuts and schedule overruns, it was still promised to be everything to everybody. Expendable launchers were to become obsolete; every satellite was to be launched on the Shuttle.

Well, that sure changed quickly after Challenger. By the end of the program it had happened again, so we lost 14 astronauts and two orbiters. Two very expensive orbiters because after all they were designed to be reusable. And sadly, the Challenger and Columba disasters also have a fair bit of hubris in them. NASA thought that rocket engines would be so reliable that they wouldn't need an Apollo-style launch escape system. And unlike Apollo, with its small and well protected thermal protection system, the Shuttle adopted a huge, fragile and totally unprotected one -- again because of the requirement for reusability.

We do need to lower the cost of space flight, especially human space flight, to make it sustainable. But that won't happen with simple-minded mantras like "reusable launch vehicle".

In fact, launcher reusability is a mirage. Like any other rocket, nearly all of the shuttle's launch mass is propellant that's certainly not reusable. Propellant, of course, costs money. And quite a bit of it was required to get such a heavy orbiter into orbit -- heavy because of things like thermal tiles, wings and landing gear that are there just to make it reusable.

Yes, a big Shuttle selling point was its unique capability to fix satellites on orbit or to bring them back to earth. But why? How many times was that actually done? Yes, the Hubble upgrades were impressive to watch. And in the early days, Shuttle astronauts also fetched a few communications satellites whose kick motors had failed. But how many satellites, including Hubble, are actually more expensive than a Shuttle launch? I would say "few or none", so those fetch and repair flights were just uneconomic stunts. Nor could the Shuttle even reach geostationary orbit or the special orbits of the GPS satellites. It had been planned to reach sun synchronous polar orbit with its many weather, spy and earth resources satellites but Challenger put an end to that. So the shuttle essentially did nothing to reduce the costs of building, launching, operating and replacing satellites.

But again I think these were largely stunts that didn't make economic sense. We're much more likely to reduce launch costs through straightforward improvements in manufacturing productivity. When you make only a few of something, each one is bound to be expensive. When you make many, you always find ways to make each one more cheaply.

People have to be clever in looking for ways to save money throughout the design of a mission or missions, not just at launch. Reusability may make much more sense elsewhere. For example, starting with Apollo 10 every mission took a brand new lunar module all the way to the moon and then threw it away in pieces just because its tanks and batteries were empty. Not only did that discard a very expensive piece of hardware, it threw away the work done by the Saturn V and the CSM in getting it all the way to lunar orbit.

Because the transportation costs are extremely high and are likely to remain so, we need much longer missions to amortize the cost of each astronaut. We need to use each piece of equipment as long as possible. And above all, we need to use in-situ resources. Apollo didn't even use sunlight, the most ubiquitous resource in the inner solar system, but that was okay because its missions were so short. We'll have to figure out how to make what we need from the moon itself. We already know how to make oxygen; the others are being worked on.

Everything will have to change to make lunar exploration practical, and because I'm afraid we can't do a whole lot to reduce earth launch costs the missions themselves will have to change.

[Glom]

Spot on there.

The other big problem with the Space Shuttle was that its reuseability was partial. The ET was expended on each flight. The TPS required virtually total rebuilding. The SSMEs needed removal and massive overhaul. The SRBs needed to be expensively retrieved from Atlantic by a marine force, mitigating some of the savings of a runway landing.

What was needed was a space station much earlier on and a much simpler spacecraft to supply it. Then real space research could have been done.

Of course, without the Space Shuttle, who knows where HSF would have ended up. Perhaps without it, Congress would just have chopped the whole thing altogether. Maybe it was a necessity just to have something, anything.

Still, it did look cool.

[gtvc]

well I was reading in the spanish blog Eureka about the original space shuttle designs and was a bigger vehicle more powerful and secure but again to reduce costs Nasa discarded lot of things
and also comparing the pictures of the first and last landing of the shuttle Discovery you can see the body of the shuttle looks cleaner in the first landing and in the last looks in someparts yellow and old I think because the reusing of some tiles.

[Data Cable]

Feb 17, 2012 13:59:35 GMT -4 gtvc said:

...comparing the pictures of the first and last landing of the shuttle Discovery...

I don't think your first photo is from the landing of STS-41-D, Discovery's first flight. This photo from KSC is described as that event:


(click for source page with description)

Here is a better-quality version of that photo from the same source as your second, spacefacts.de. Note that the patch of black tiles on the front of the thruster pod is missing in this photo, but present in both of yours, indicating that they could not be of the same event.

[Edit: The image url of gtvc's first photo indicates it was STS-26, which was Discovery's 7^th flight.]

...you can see the body of the shuttle looks cleaner in the first landing...

Also note that much of the surface detailing in the photo of the final landing is also visible in the first landing. Your first photo above is probably overexposed a bit, blowing out most of the detail on the orbiter's surface. Even the photo I linked above appears to be a bit washed out. In the photo of the final landing, however, the sun angle is high and slightly toward the camera, shading the near side of the orbiter and bringing out much more detail. It's also, quite simply, a sharper photo.

[gtvc]

wikipedia again!!! , thank you for the pictures but looks new here too, all white and black no yellows or grays in the tiles my point is for lack of budget was nasa reusing tiles from past flights in different areas of the shuttles

[ka9q]

Nothing wrong with reusing tiles as long as they meet specs. Cosmetics aren't as important as function.

I thought each tile was custom-made for its location, so I didn't think they could be moved around. They might be moved between orbiters, though.

[Data Cable]

I think I see where you might have been confused, gtvc. STS-26 was Discovery's lowest-numbered mission, but not its first. Looking at the list of Space Shuttle missions, they were numbered sequentially, STS-1 to -9, through 1983.

In 1984, missions started to be numbered STS-41-_, -51-_ or -61-_, ending in a letter, apparently in the order missions were planned, but not necessarily launched. The reasoning behind the numbers, however, eludes me. (Planned to launch in 1984, '85 and '86, respectively? 51-A launched in Nov. '84 and 61-A in Oct. '85.) It was during this period that Discovery first flew, on STS-41-D. The last of these was Challenger's ill-fated STS-51-L.

With Discovery's "Return to Flight" mission in 1988, they apparently also returned to simple consecutive numbering (again, not necessarily launched in the order they were planned) with STS-26 (the 26^th Space Shuttle mission), continuing that scheme through the end of the program. STS-41, -51 and -61, without the lettered suffixes, were even re-used, just to further confuse the issue.

[Edit: D'oh! Once again, not looking at sources right in front of me. See the top of the Wikipedia page linked above for an explanation of the numbering system. Nutshelled: Superstition over the number 13 and Federal fiscal year calendar offset.)

[George Tirebiter]

I'm not sure where you got the notion that all of the tiles would be replaced after each mission. The tiles were meant to be reused for the entire life of the vehicle, and were supposed to be replaced only if damaged.

[gtvc]

ok thank you.