[mak120]

Can't help feeling a little sad. The same feeling when the Concorde was retired.

Its not sad that these awesome machines are being phased out. Machines/designs become old and obsolete all the time. But in this case, there is simply nothing better to replace it. It is as if this was as far as mankind could go and have to turn back.

Here's to hoping that some day there will something more ingenious that will be a worthy successor.

[rbanffy]

This one was obsolete well before its first flight. Astronauts could be delivered to LEO with expendables for less money. Satellites and supplies to the ISS could be delivered without risking human lives and, again, for less money. By using expendables you would end-up building modular spacecraft, iterating designs and improving them on every launch. By using less money you get to build more expendables.

The shuttle is a beautiful machine, but it's even less practical than the Concorde. And many, many orders of magnitude more expensive.

Sadly, a Saturn/Apollo stack would be more ingenious and a worthy successor.

That said, the SRBs, the tank and the engines could be put to good use. I guess the tank could be adapted to LOX/Jet-1 and engines and payload could be fitted on it.

The orbiter is the problem.