Didn’t fly but a fraction of it’s planned mission rate? 60 flights per year was abandoned back with the flyback boosters back in the 1970s. Shuttle was limited to 8 flights per year for bureaucratic, not technical reasons. People in the Shuttle business are continually shocked to learn that we actually flew 9 missions in 1985, even though it’s all right there on every list of Shuttle flights. Plans were to fly 16 missions in 1986. I don’t think we would have made it, even without Challenger, but another 9 or 10 seems reasonable. And given proper funding, that would have been sustainable as well.

Lost 40% of the fleet? Of course. Put 10 drunks in 10 cars, and you’ll lose 40% of the “fleet” as well. Don’t blame the vehicle for the mismanagment of th program.

What exactly is the path you are referring to that is being abandoned? Reusable vehicles? Winged vehicles? Horizontal landing vehicles? Parallel-staged vehicles? Some parts of the Shuttle concept will be mandatory for any future viable launch system (viable in a sustainable economic sense). Other parts were, as you pointed out, questionable compromises.

More importantly, CEV abandons any pretense of aircraft-like turnaround. That’s a huge mistake. It basically means that CEV will not be relevant to the needs of the anybody but NASA. It’s a dead end before it even gets off the drawing board, let alone the launch pad. Shuttle, of course, did not accomplish aircraft-like turnaround. But compared to what came before it, it was an important first step in that direction. Please don’t complain about the Shuttle flight rate until you look at the planned CEV flight rate.

You asked, if Shuttle was so great, why haven’t other space powers developed similar technology? Well, for starters, there was only one other space power, and that was the Soviet Union. They attempted to copy the technology, with extremely limited success (a single unmanned orbital flight). You’ll notice that the Soviet Union no longer exists. No other nation or group of nations has the capability to develop something like Shuttle, certainly not with existing budgets.

Any system that provides earth-to-orbit and orbit-to-earth transportation will have to fly in multiple realms: launch, orbit, hypersonic flight, and subsonic flight to landing. Every system that has ever performed that task has done that, from Vostok to Shuttle to the Chinese Soyuz-derived vehicle. Capsules with parachutes are one solution to the hypersonic+subsonic problem. Given the size limitations on parachutes, they are certainly not optimal for all missions, any more than the Shuttle is. ALL earth-to-orbit-and-back systems are kludges, by necessity. That includes CEV.

Did you know the Shuttle was capable of unmanned flight, including autolanding? There are still 3 pushbuttons in the cockpit to deploy the landing gear, but aside from that, no human presence is required. Of course the fighter mafia that controls the operation of the vehicle wouldn’t allow that function to be automated, but there have been multiple studies on conversions to operate as an unmanned cargo vehicle (incuding a “Shuttle-C” version that dispensed with returning anything save the SRBs and a jettisonable engine pod). Again, policy killed that. But everything you need is there, if you prefer that sort of thing.

Please don’t whine about the wasted cost and weight for life support systems. If you are going to put human beings in space, you are going to have a life support system. You can argue whether it is better to put that in a seperate payload (capsule) or in a crew cabin fixed to a launcher. In the end, it’s a mission-concept decision. Choose how you want to operate, and the vehicle designs itself to fit your concept. If you just want to go to earth orbit and back, that capsule had better be VERY modular, or it’s a dumb way to do it. If you want to go to the moon, detachable capsules make sense for some mission concepts.

I agree that atmospheric flight controls and retractable landing gear are absurd requirements for a space vehicle. But the Shuttle is not a pure space vehicle…it’s an earth-to-orbit-to-earth vehicle. Atmospheric flight controls and landing gear are the price you pay for rapid turnaround. If you just want to land a capsule and put it in a museum, you don’t need any of that. But if you had to put your car in a museum after a single trip to the grocery store, I wouldn’t own one, and neither would you.

Here’s another way to look at it…if capsules are better, why did the Russians abandon Mir for the ISS? You could build Mir with a simple, proven system (Soyuz) for lifting people, and other systems (Proton) for lifting cargo. You couldn’t build ISS that way…it was designed from the start to utilize all the extra capabilities that Shuttle provided that were unavailable anywhere else. Capsules may be simple, but a capsule on an expendable rocket is a fiendishly expensive way to get people into orbit. And despite making the capsule semi-reusable (10+ flights before retirement of each serial number) and using as much Shuttle-derived technology as possible to hold down the cost, Constellation is still fiendishly expensive. That’s roughly 16 billion 2005 dollars per year for 2 sorties of 2 vehicles (1 stick launch plus 1 HLV launch). This is progress?

Shuttle was far from perfect. But for something designed in the 1970s and first flown in the 1980s, it was revolutionary. Compared to what came before it, it was as advanced as say, a Ford Tri-Motor was to the Wright Flyer. Note that we don’t use Ford Tri-Motors to deliver the mail anymore…they are obsolete, and the Shuttle is rapidly becoming obsolete as well. But we didn’t go back to “biplanes using the latest Tri-Motor derived techology”, and we shouldn’t go back to concepts recycled from the 1960s, either.

What will we do to ensure that the private space cowboys do not litter their paths with heavy metal cowpies whizzing along at 7 km/sec in LEO?

NASA’s budget is currently around 16 billion a year, of which about 1 billion is currently for Constellation development. You think you could build a system of prop depots (and keep them supplied), not to mention developing the technologies and spacecraft required for all this? It would be bigger than Apollo in terms of money and investment. If Congress wants to give NASA this money, fine. Until then, they’re doing a damn good job with the gum & bailing wire they’re given.

From the start, it was a political design, not an engineering design. It was justified by claims to reduce the cost to orbit of everything, which also required giving it a monopoly on launches – even for military/intelligence satellites.

If the Shuttle was so great, why haven’t other space powers developed similar technology?

Putting on my engineering hat, let me point out a few obvious problems with the idea:

1) It has to fly in multiple realms – launch, orbit, re-entry, hypersonic flight and subsonic flight to landing. This means lots of complex systems and dangerous phase transitions. The Shuttle is, basically, an enormously expensive kludge – a truly inelegant system.

2) It requires a human crew. That means the probability of failure must be dramatically lower (for political and human reasons) than an unmanned vehicle. Thus everything we put into orbit had to fly on a man-rated vehicle and be man-rated itself. This dramatically raised costs and reduced mission rates.

3) The manning requirement also caused a need for life support systems. More cost, more wasted weight, more potential for failure.

4) The hypersonic flight requirement requires an aircraft-like vehicle, just for the short time this space-ship is coming home. That vehicle required the invention of the fragile insulating tiles (because an aircraft couldn’t use simple ablation). It required atmospheric flight controls, and retractable landing gear. In other words, it put all sorts of absurd requirements on a space vehicle.

Now going back to a simple system for lifting people, with other systems for lifting cargo (many in the private sphere) is much better. The new manned system, if NASA doesn’t screw it up too much, simply uses a scaled up rocket (a ’60s technology), a capsule with long proven, simple reentry and landing technology (Apollo, Soyuz), and little else.

In Engineering, KISS is a good principle – something grossly ignored by the Shuttle politicians and bureaucrats who forced the Shuttle design.

http://en.wikipedia.org/wiki/Interplanetary_Transport_Network

“The Interplanetary Transport Network (ITN) is a collection of gravitationally determined pathways through the solar system that require very little energy for an object to follow.”