quinta-feira, 15 de maio de 2008

O botão para destruír o Space Shuttle

Como acontece em todos os veículos espaciais, também o Space Shuttle tem um botão para o destruír no ar, caso algo corra mal! Mesmo com a consciência de que isso matará todos os astronautas a bordo, se o Shuttle se desviar da sua rota (ver figura abaixo) mais do que o determinado, ou se ocorrer qualquer outra anomalia que possa pôr em risco as pessoas em terra ou no mar, este será destruído por um conjunto de cargas explosivas comandadas pelo Range Safety Officer. Os astronautas costumam dizer piadas do tipo 'nunca chatear o RSO'.

Até hoje, o RSO só teve de actuar uma vez durante o programa Space Shuttle. Após a explosão do Space Shuttle Challenger, os motores auxiliares de combustível sólido - Solid Rocket Boosters - continuaram a voar desgovernados - como decerto se recordarão os que assistiram ao trágico evento. Para evitar riscos graves, foram detonados a partir de terra poucos segundos depois de se ter constatado o que havia acontecido.

Fonte: Popular Mechanics

As Shuttle Lifts Off, NASA Will Man Destruct Switch—Just in Case
If the looming Discovery mission or any other between now and the spacecraft's retirement loses control, NASA is prepared to ditch it in the Atlantic—or blow it up.
By Joe Pappalardo
Published in the June 2008 issue.

Each time the space shuttle rises from its launchpad at Cape Canaveral, Fla., an Air Force officer waits anxiously for the first 2 minutes to pass safely. If the spaceship were to veer off course and endanger a populated area, this range safety officer would bear the terrible responsibility of flipping a pair of switches under a stenciled panel reading “Flight Termination.” The first switch arms explosives on the shuttle’s two solid rocket boosters. Flipping the second switch would detonate them, destroying the shuttle and crew.

“If something happens when it’s just off the pad, there’s only a couple of seconds [to react],” says Bryan O’Connor, a former shuttle commander and NASA’s chief of safety and mission assurance.

But the danger continues as the craft streaks upward. If a spaceship’s flight controls or engines malfunction, toxic fuel and fast-moving debris could threaten people below. After about 2 minutes, the spent solid rocket boosters drop away, taking the charges with them. After that, problems severe enough to threaten people on the ground would leave the crew with two options: Enter orbit and fly around the Earth for a landing at California’s Edwards Air Force Base, or steer into the ocean. Ditching at sea would be extremely dangerous—astronauts would need to exit the ship at 20,000 ft., without the benefit of ejection seats. “After Challenger, we installed parachutes, survival suits and individual rafts, as well as an extendable pole used to clear the escapees from the wing when they exit the hatch [while in flight],” O’Connor says.

NASA’s next space vehicles will include a rocket-powered escape pod for launch emergencies.

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