Friday, October 15, 2004
Genesis crash linked to upside-down design
New Scientist: "Sensors to detect deceleration on NASA's Genesis space capsule were installed correctly but had been designed upside down, resulting in the failure to deploy the capsule’s parachutes. The design flaw is the prime suspect for why the capsule, carrying precious solar wind ions, crashed in Utah on 8 September, according to a NASA investigation board.
The sensors were a key element in a domino-like series of events designed to release the parachutes. When the capsule - which blazed into the atmosphere at 11 kilometres per second - decelerated by three times the force of gravity (3 Gs), the sensors should have made contact with a spring.
'It's like smashing on the brakes in your car - you feel yourself being pushed forward,' says NASA spokesperson Don Savage.
The contact should have continued as the capsule peaked at a deceleration of about 30 Gs. Then, when the capsule’s deceleration fell back through 3 Gs, the contact would have been broken, starting a timer that signalled the first parachute to release.
'But it never made the initial contact because it was backwards,' Savage told New Scientist.
The sensors, which are estimated to be less than an inch (2.5 centimetres) wide, were apparently installed in a circuit board in the wrong orientation - rotated 180° from the correct direction. But the problem stemmed not from the installation but the design, by Lockheed Martin, based in Bethesda, Maryland."
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