Performance: 204420 lbf or 909300N thrust, isp 339 sea level, 266230lbf or 1184300N thrust, isp 436.5 vacuum |
Here's the story of what happened to the VentureStar. It could have flown. The pic above is the test of the new Aerospike engine, which was done this year. Interest in this may still exist out there.
Looks like it was a decision by Bush or Cheney to cancel the thing, though, back in 2001.
The VentureStar may now be nothing more than a memory, but it nearly became part of NASA, the commercial fleet and indeed even the US Air Force, had it of not been for some controversial key decisions during the construction of the technology demonstrator, the X-33.
- Testing and construction had been going well during the assembly of the scaled down version of the VentureStar
- ...Rocketdyne’s decision to use Narloy-Z – a heavy copper alloy – saw changes to the flight control surfaces due of a aft-heavy center of gravity. This would prove to be a major – and defining – problem later in the process.
- Yet still, the LH2 tank – a large multi-lobed structure – was to be the single most challenging project for engineers involved in the X-33 program, even if they had been able to use Al-Li alloys.
- Skunk Works’ designers of the LH2 tank had heard from engineers that storing liquid hydrogen in a pressurized composite (notably material IM7/997-2) tank with the hollow honeycomb walls was simply doomed to failure – but their advice was ignored.
- engineers – predicting the impending problem – had a solution already at hand...This idea had to be rejected, due to the 500 kg of extra weight being added...already having serious fallout on the design due to the heavy engine ramps [comment see Rockedyne's decision on Narloy-Z above]
- engineers had already started the process on having their own Al-Li LH2 tank ready for fabrication...Ironically this new tank weighed in less than the composite tank
- Then the hammer blow...former NASA director Ivan Bekey appeared in front of the Subcommittee on Space and Aeronautics...His testimony...proved to be the final blow for the X-33 VentureStar
- Each time the Air Force made requests to take the X-33 project as their own, they found the opportunity denied at the highest level of US government.
- the White House that vetoed any new evaluations of the X-33.
- But for those that worked on the X-33, the pure complexity of the new system – and the chain reactions felt from issues and bad decisions such as the heavy engine ramps to the resulting need for the low weight of the LH2 tank – to the lack of options open to use a solution for the LH2 tank failures, turned her from a potential leap in space vehicle technology, to one that became a $1.5 billion white elephant to the tax payer.
A questionable decision given the details above. It doesn't matter which political party, they are all screw-ups.
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