Launching a new spacecraft is an extremely tense time for NASA, especially when it carries the lives of several astronauts on board. Despite rigorous testing beforehand, the unpredictable can and has happened in the past, so the space agency has been trialling its latest contingency for a worst-case scenario, in which the crew need to be brought safely back down to Earth.
Developed originally for the Orion spacecraft as part of the cancelled Constellation programme (and now a vehicle designed for escaping the ISS in an emergency), the Launch Abort System (LAS) has since been tested by the Orion Pad Abort 1 team at the White Sands Missile Range, New Mexico. The test propelled a dummy crew module at 716 kilometres (445 miles) per hour to around two kilometres (1.2 miles) high, with a motor providing 227,000 kilograms-force (500,000 pounds-force) of initial thrust to get it off the ground. It is kept on course by an attitude control motor (ACM) with eight thrusters, with a combined 3,175 kilograms-force (7,000 pounds-force) of thrust.
The jettison motor kicks in when the abort motor burns out: explosive bolts fire and the jettison engine separates the LAS from the crew module. Once the module is clear, its recovery parachutes deploy and then it drifts gently back to the ground.
This 2010 test was the first US-designed abort system since Apollo and it was a total success. The data gathered during the Orion LAS test can be used for refining the design of future abort systems, providing ever better ways for the crew to escape a launch emergency.