SpaceX now knows why astronaut capsule exploded
After nearly three months of investigation into what SpaceX at first only called an “anomaly,” the company on Monday announced the likely culprit of an explosion that blew apart its Crew Dragon astronaut capsule during a test on the Space Coast in April.
A leaking component in the vehicle’s propulsion system began the chain of events that ended in destruction, said Hans Koenigsmann, SpaceX’s vice president of build and flight reliability, during a press conference call Monday afternoon.
Because of delays caused by the accident, Koenigsmann said it’s going to be “increasingly difficult” to get astronauts aboard a Crew Dragon capsule and into space by the end of 2019, though not impossible.
The April 20 accident happened when the Elon Musk-owned rocket company was conducting static fire tests of the vehicle’s engines. The capsule on the test stand that afternoon had already successfully flown to space one month earlier, completing the first major test of SpaceX’s partnership program with NASA, which will carry astronauts back to space from U.S. soil for the first time since 2011 on vehicles built by SpaceX and Boeing.
The test was being conducted to prepare SpaceX for an in-flight abort test that would prove the capsule’s thrusters could safely move the vehicle and its astronauts away from the rocket in the case of an emergency midflight.
A static fire of a set of thrusters that help the vehicle maneuver in space went by without incident.
But just about 100 milliseconds SpaceX ignited the abort thrusters craft, the vehicle exploded.
At the time, SpaceX offered few details on the extent of the damage to the vehicle. A leaked video from the test started making the rounds online, showing that the craft, in fact, blew apart. SpaceX confirmed the before on the spacecraft was
Following the accident, SpaceX and NASA, along with help from the Federal Aviation Administration and the National Transportation Safety Board, put together an accident investigation team to discover the root cause of the explosion.
With about 80% of that work now done, SpaceX offered its first breakdown of what went wrong.
The leak caused liquid oxidizer — a key component in the vehicle’s propellant — to cross over into the wrong set of pipes, the pressurization system. That’s when the high-pressure oxidizer reacted with a titanium valve leading to an explosion that “destroyed” the Crew Dragon capsule at Cape Canaveral Air Force Station’s Landing Zone 1, sending plumes of smoke over Cocoa Beach. No one was hurt.
Burn marks found on the valve, as well as data and debris collected at the site confirmed the company’s suspicions. SpaceX lost 12 days after the explosion. also performed a series of tests of the flammability of the valve’s titanium components at the company’s rocket development facility in McGregor, Texas. The investigation, however, is ongoing.
“We didn’t quite expect that [liquid oxidizer] driving into a titanium component could cause such a violent reaction,” Koenigsmann said. Titanium has been used safely on spacecraft for decades.
“Overall it’s something the components should not have done,” he said. “[We learned] a very valuable lesson on something going forward that makes the Crew Dragon a safer vehicle.”
The abort thrusters, SpaceX said, were recovered from the test site intact, supporting the company’s belief that the abort system is not faulty. Koenigsmann said at a prior press conference that the safety thrusters have been tested more than 600 times with no issue.