Boeing's CST-100 Starliner capsule passed a major milestone today as it successfully completed a launch pad abort test. At Launch Complex 32 at the US Army’s White Sands Missile Range in New Mexico, the unmanned spacecraft lifted off under its own power and executed a 95-second flight that demonstrated its ability to propel itself and its crew safely away from its Atlas V booster in the event of an emergency before liftoff.
According to Boeing, the purpose of the Pad Abort Test was to demonstrate that the complex systems aboard the Starliner capsule and its service module work together properly in actual flight conditions. This included showing that the rocket thrusters can perform at the needed levels and that the parachutes can deploy properly and support the weight of the capsule.
The abort test began with the Starliner firing its four Launch Abort Engines (LAEs) as well as its Orbital Maneuvering and Attitude Control (OMAC) thrusters, which generated a combined thrust of 190,000 lb. Five seconds after launch, the LAEs shut down, but the maneuvering thruster continued to fire for another five seconds as the craft automatically performed a pitch-around maneuver at an altitude of 4,500 ft (1,400 m) to position itself for landing.
About 30 seconds into the flight, the crew module deployed two of its three parachutes and the service module was then jettisoned at about the 34-second mark. Though one parachute failed to deploy as planned, the Starliner descended at a safe speed while the service module fell to Earth. At one minute, the crew module's heat shield was jettisoned, so the craft could deploy the airbags that absorbed the force of impact when it touched down at about 95 seconds.
Boeing says that the Starliner crew module has been recovered and is undergoing a full evaluation to determine how well the systems functioned during the abort test and how well it performed during the landing. The latter is particularly important because the Starliner is designed to be reused up to 10 times.
"Today’s pad abort test was a milestone achievement for our CST-100 Starliner team, for NASA, and for American human spaceflight," said a Boeing spokesperson in a statement. "We will review the data to determine how all of the systems performed, including the parachute deployment sequence. We did have a deployment anomaly, not a parachute failure. It’s too early to determine why all three main parachutes did not deploy, however, having two of three deploy successfully is acceptable for the test parameters and crew safety. At this time we don’t expect any impact to our scheduled December 17 Orbital Flight Test. Going forward we will do everything needed to ensure safe orbital flights with crew."
The Starliner's next flight will be unmanned Orbital Test Flight to the International Space Station (ISS), which is scheduled to lift off from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida on December 17, 2019.