NASA has spectacularly and successfully tested the launch abort system - the ejector seat, as it were - for its new Orion crew capsule. There's just one problem: according to President Obama's stated plans, Orion will never be launched with crew aboard.
The Pad Abort 1 test took place today at the White Sands Missile Range at 2pm UK time, and it simulated what would occur in the event of an Orion crew needing to escape following a disastrous mishap to their rocket stack as it stood on the launch pad.
In such a case, the Pad Abort rocket system fitted above the nose of the astronauts' capsule is triggered, pulling the capsule up off the failed, perhaps exploding launch stack almost instantly. The Abort rocket is exerting approximately 250 tonnes of thrust within "a fraction of a second" of being triggered, according to NASA, accelerating from 0 to 600 mph in two seconds, with the capsule dragged behind it within a cone of flame from the exhausts.
Once it has abruptly blasted clear of the stack, the abort rocket can steer itself in any direction using eight side-firing exhausts mounted at the top of the Abort system spike. After soaring free for approximately ten seconds, these are used to flip the flying capsule and spike end for end so that the capsule is descending to Earth with the Abort spike trailing.
After twenty-one seconds, a further jettison motor fires and the Abort spike blasts clear of the capsule, which then descends by parachute bringing the crew in to a safe landing.
If, as expected, the Abort system isn't required during launch and ascent, it is jettisoned once the Orion is in space. According to NASA, the rocket getaway spike is "a key element in NASA's continuing efforts to improve safety as the agency develops the next generation of spacecraft".
The only snag with that is that President Obama has lately cancelled the Ares I rocket stack which was intended to lift a crewed Orion into space. He originally axed the Orion too, but later relented saying that it might be sent into space unmanned for attachment to the International Space Station (ISS), there to serve in place of the current Soyuz capsule as the station's lifeboat.
The President has also said that an unspecified heavy-lift rocket to replace the similarly cancelled Ares V will be chosen in 2015 for the purpose of getting deep-space missions (that is, ones beyond the Earth-Moon system) into orbit. However, this will probably not be rated to carry astronauts, in order to reduce costs.
Thus, there would seem no rocket on the horizon that would ever lift a manned Orion off Earth. Orion or the craft which develop from it might well take part in deep-space manned missions in coming decades, but this wouldn't require a pad-abort system.
Against this background, it seems perhaps a little odd that NASA bothered to carry out today's test at all. ®