In preparation for company’s first human-rated space missions, on May 6, 2015, SpaceX conducted successful Pad Abort Test of Crew Dragon, a vehicle designed to carry astronauts into a low Earth orbit, from Space Launch Complex 40 at Cape Canaveral.
Pad Abort Test is a trial run for spacecraft's launch abort system (LAS), designed to quickly get the crew and spacecraft away from a rocket in the event of a potential failure. It is similar to an ejection seat for a fighter pilot, but instead of ejecting the pilot out of the spacecraft, the entire spacecraft is “ejected" away from the launch vehicle.
Crew Dragon abort test statistics: 0 to 100 mph in 1.2 seconds... Maximum acceleration was 6X gravity, altitude 1187 m, lateral distance 1202 m, and velocity 155 m/s. Elon Musk, SpaceX CEO and founder
Conventional launch abort systems are powered by a rocket tower mounted on top of the spacecraft. During an emergency, the tower would ignite and lead the spacecraft away. This system works well on a launch pad and for a few minutes of ascent, but once the launch vehicle reaches a certain altitude, the system is no longer useful. SpaceX's LAS, however, is integrated directly into the spacecraft, what means Crew Dragon will have launch escape capability from the launch pad all the way into orbit.
SpaceX's launch abort system uses eight SuperDraco rocket engines built into the walls of the Crew Dragon spacecraft. These engines are capable of producing near 54 ton of axial thrust in under a second, which results in transporting the Crew Dragon spacecraft away from the launch pad (or a flying launch vehicle) for nearly 100 meters in 2 seconds, and more than half a kilometer in just over 5 seconds.
SuperDraco engines are designed to be used not only for launch escape but also to enable Crew Dragon land propulsively on Earth or another planet with the precision of a helicopter. They provide rapid reusability of the spacecraft as well. After landing, Crew Dragon can be refueled and flown multiple times, drastically lowering the cost of space travel.
SpaceX is making Crew Dragon within the NASA's Commercial Crew program, intended to stimulate development of privately operated crew vehicles able to deliver US astronauts into a low Earth orbit. The vehicle holds seats for 7 passengers, and includes an Environmental Control and Life Support System (ECLSS) that provides a comfortable environment for crewmembers.
Not only SpaceX takes part in the multi-billion NASA's initiative. Boeing develops CST-100 human-rated spacecraft that is expected to be launched atop United Launch Alliance's Atlas V rockets. Blue Origin and Sierra Nevada Corp., both taken part in Commercial Crew program earlier, currently work with NASA on an unfunded basis.
Pending the outcome of the pad abort test, SpaceX will then conduct an in-flight abort test using its Falcon 9 booster. With the in-flight abort, the company will test the same LAS, however this time in mid-flight during an actual launch. Both the pad abort and in-flight abort tests are key milestones for SpaceX that move company closer to the first crewed flights presently scheduled for 2017.
The pad abort test was one of two remaining milestones under SpaceX's Commercial Crew Integrated Capabilities agreement with NASA. The other is the in-flight abort test. Each milestone is worth $30 million. An in-flight abort test is expected to be performed at Vandenberg Air Force Base later this year.