Don't we currently have a glider? Or is it because this would seem to be unpowered on the up and down (with a detachable, and I'm guessing, expendable propulsion pack)that would make it smaller? And does anything in the new proposals seem to address the reusability of the system? As I remember it, the original shuttle was supposed to be cheap and highly-reusable but ended up costing at least an order of magnitude more per launch than originally intended.

No, what makes it smaller is it doesn't have to bring home multi-ton cargo loads, as the shuttle does now. Also, it would not have the gigantic cross-range recovery requirements the Air Force saddled the shuttle with (IIRC, they wanted it to be able to glide a LONG way with a heavy payload, making the shuttle much heavier than it had to be).

Reusability is nice but is proving to be something of a chimera in regard to current spaceflight technologies. Because man-rated stuff has to be SO reliable, and spaceflight is so damned difficult anyway, it usually is cheaper (sometimes MUCH cheaper) and safer to toss something after one use and build a new one.

Wouldn't gravity bring them home for us anyway? Melted and flattened, but they'd come home...

Or is the goal to have the mission payloads be 'self-returning'? I'm asking as I assume that the payloads themselves shouldn't change that much, should they?

The shuttle was an excellent idea in concept; its re-usability should have made it an immensely profitable enterprise for NASA, with each shuttle paying for itself within five years and having another five years of projected life beyond that.

What went wrong? From what I heard, apparently the estimation of the stresses of space travel upon the re-usable components were off by at least an order of magnitude. The cost of putting the shuttle back together and sending it into space again were initially projected to be in the $50 million to $100 million range, but the actual cost soared into the tens of billions for each launch, the vast majority of which went into repair and maintenance of the shuttles themselves. Without the predicted profits, the shuttles could not be replaced, and they have all been pressed into service at least a decade beyond their projected lifespan. Once they all fall apart most spectacularly, we will probably go back to one-shot rockets for the forseeable future.

The reason were both political and technical. After we beat the Russians to the moon, America gave up on developing the technology necessary to make the Shuttle System workable and inexpensive. Without the economic backing we got a series of compromised systems, and well let's be honest you get what you pay for. There was a very promising replacement the X-33 in the works that was killed once Bush took over in 2001. It was one step away from fulfilling the dream that von Braun had for the Shuttle program. I wrote up a nice bitter diatribe on it, last week on Daffodillane.

R: Keep in mind that, unlike virtually every other manned space initiative put forward since the shuttle itself some thirty-five years ago, NASA is taking Bush's "moon to mars" directive seriously. More importantly, so is congress. AvWeek is reporting the entire agency is undergoing a slow, grinding re-alignment with its new mission. Almost EVERYTHING nasa will be doing from this point forward will have one in a chain of two goals: getting people back on the moon, and then sending them to Mars.

This means yes, actually, the cargos will change, and fundamentally. We'll be going into a sort of "Apollo II". Not as gung-ho, hopefully not as expensive, and not in such a rush, but with the same essential goal... "to go where no-one/man..."

In actual fact, the program will almost certainly end up looking like what von Braun really wanted back in the 50s... a smallish vehicle to launch the people, and a really monstrous vehicle to launch the cargo. Both are assembled in earth orbit, and off they go.

He didn't get what he wanted way back then because it would take too long. As I recall, he was disappointed because he knew the "lunar rendevous" option wouldn't commit the US to long-term manned space exploration, whereas "earth rendevous" would.

Let's hope his final hunch is right. Regardless, we'll all be finding out soon enough.

Yeah, developing the technology. Like cold fusion, all that promising technology wasn't scrapped because it was impossible, unfeasable, or the brand new technology blew up in the test lab. It has to be due to the shadowy forces of anti-progress, necessarily personified by the Bush Administration.

The X-33 was a pipe dream pure and simple. The weight fraction was so low, even *with* the amazing exotic fuel tanks (which didn't work and had to be abandoned), it meant that the flight vehicle would never reach its design goals. It was simultaneously showing every sign of quintupling its budget requirements before the first flight was ever made. Gore would've killed it just as quickly as Bush did, and for all the right reasons. I am quite glad it's dead, as I have no wish to see a "Shuttle II" program.

The far more proper question is why did NASA select the X-33 when the DC-X project had a *working, flying* design ready for ballistic and then orbital testing? AvWeek's conclusion was it simply wasn't "new" enough... too conventional, too pedestrian, too "not invented here." So instead of choosing a working program already in progress using, for the most part, off-the shelf componentry (which was after all the goal of the program) they chose the super-exotic one-off that existed nowhere but in the minds of its designers. Oh it looked pretty, but it was doomed to fail as soon as the contracts were signed.

That the X-33 had extremely high "geeky cool" factor there can be no doubt. But it simply would not have worked, at least not without cost over-runs and program delays nobody could see the end of, threatening billions of extra dollars and years of extra time spent on a design nobody was sure would actually work.

I'm far happier with NASA's current approach, using existing, improved, or derived designs of already known-to-work systems. I'd much rather see them driving somewhere exciting in a Model-A than going nowhere trying to build a McLaren F-1.

Because you see it's not the vehicle that's exciting, it's the journey.

Maybe you should ask your dad his opinion. von Braun was at the Cape when your dad was working on the Apollo programs. I think your dad had contact with him or at least met him several time.