Five Shuttles flew to space - Columbia, Challenger, Discovery, Atlantis, Endeavour. And Buran - the one which flew (other Soviet spaceplanes would have different names, so Buran is like Columbia, not like Space Shuttle) - didn't have e.g. the life support system; it was rather a development flight, than a demonstration of a complete system. Still Buran (as a combined name, like Energiya-Buran program) had some better capabilities e.g. no toxic propellants onboard (Shuttle has to be chemically "pacified" after each landing) and longer orbital life (with cryogenics onboard).

> Buran (as a combined name, like Energiya-Buran program) had some better capabilities e.g. no toxic propellants onboard (Shuttle has to be chemically "pacified" after each landing) and longer orbital life (with cryogenics onboard).

My point is that they aren't capabilities, just specifications and promises for a cutting edge, developmental technology.

It didn't fail for any technical reason though, the whole government behind it was stumbling at the time on it's way to full collapse from a heady medley of internal and external forces.