Even the shuttle's critics agree with supporters that the vehicle is well suited for this kind of work. It is a spacefaring ferry that carries cargo and astronauts into Earth's orbit. Still, the shuttle has failed to come close to its promoters' grandest promises. When the program was proposed in the 1970s, NASA said it was capable of launching 60 shuttles a year. Last year, it managed only three launches.
Reliability is a relative concept, and many question just how reliable the shuttle is.
The tragedy resulted in a 32-month hiatus in the shuttle program, and the fleet has been grounded many times since by mechanical problems. It is supposed to leap into space on a single-stage reuseable rocket, without the disposable external fuel tanks or recoverable external rockets that are part of the shuttle. Supporters also hope it will be more reliable than the shuttle and cheaper to operate, liberating funds for more weather satellites and other projects that might win public support. The only problem with VentureStar is that it doesn't seem to work. So far, no joy.