SpaceX says that it believes it has discovered the reason behind the explosion of its Crew Dragon spaceship back on April 20. The craft exploded on the test stand during an uncrewed ground test of its escape thrusters. The spaceship was destroyed in the explosion. No one was hurt during the incident.
Crew Dragon is a seven-person space capsule designed to ferry NASA astronauts to and from the International Space Station. NASA’s Commercial Crew Program is paying SpaceX to develop, build, and test the spacecraft. In March, the Crew Dragon capsule in question launched into orbit, docked with the space station, and then returned to Earth in an uncrewed demonstration test. That test was viewed as a success.
During the April incident, SpaceX was testing two sets of thrusters on the spaceship: low-pressure thrusters called Dracos and high-pressure thrusters called Super Dracos. The Dracos are used for maneuvering while the Super Dracos are used to power the spaceship’s escape system. The test of the smaller Draco engines succeeded, but the test of the Super Draco system failed as soon as they began pressurizing the thrusters.
Hans Koenigsmann, SpaceX’s vice president of mission assurance, said that with the investigation into the explosion “80 percent done,” investigators believe they have discovered what went wrong. According to the investigators, a leaky valve on the system “caused a violent reaction” once the escape system was activated. Investigators found burn marks inside the pressurization system’s check valves and the blast coincided with activation of the system.
SpaceX, NASA, the US Air Force, and other members of an investigation team spent weeks picking up Crew Dragon pieces across the launch site in Cape Canaveral, Florida. There is a planned fix for the issues uncovered during the investigation, but it remains unclear whether SpaceX will be able to launch Crew Dragon with astronauts before the end of the year.