A senior SpaceX official confirmed Thursday that an “anomaly” during an April 20 ground test destroyed a Crew Dragon spacecraft meant to clear the way for the launch of two astronauts this summer. SpaceX Vice President Hans Koenigsmann added it’s not yet clear how long the program will be delayed or even if a piloted mission might get off the ground before the end of the year.
“We’re going to learn a lot, and I think this will make the program actually safer at the end of the day,” Koenigsmann, SpaceX’s vice president of build and reliability, told reporters. “In terms of schedule, finishing the investigation and resolving this anomaly is our prime focus right now. We will see what comes out of it.”
While he declined to speculate how long the failure probe might take, he said, “I hope this is a relatively swift investigation. I don’t want to completely preclude the current schedule, (but) certainly not great news for the schedule overall.”
The Crew Dragon spacecraft was launched on a successful unpiloted test flight to the International Space Station in March and was being prepared for an in-flight test of its emergency abort system, designed to quickly fire and propel the craft away from a malfunctioning booster, when something went terribly wrong.
In the company’s first detailed update, Koenigsmann said the mishap occurred about a half-second before the Crew Dragon’s eight Super Draco abort engines were to be fired on a test stand at Cape Canaveral Air Force Station.
“At the test stand, we powered up Dragon, it powered up as expected, we completed tests with the Draco (maneuvering) thrusters, the smaller thrusters that are also on the cargo Dragon,” Koenigsmann said. “And then just before we wanted to fire the Super Dracos there was an anomaly and the vehicle was destroyed.”
Spectators along area beaches saw billowing clouds of reddish-orange smoke rising above the Air Force station in the aftermath of the incident, an indication to veteran launch observers that toxic hypergolic propellants, like those powering the Crew Dragon’s thrusters, had been released.
As is standard procedure for such tests, the area was evacuated well ahead of time and winds were blowing out to sea. There were no injuries.
“Because this (was a) ground test, we have a high amount of data, a huge amount of data from the vehicle and the ground sensors,” Koenigsmann said. “It is too early to confirm any cause, whether probable or root, but the initial data indicates the anomaly occurred during the activation of the Super Draco system. That said, we’re looking at all possible issues and the investigation is ongoing.”
He said the abort engines have been fired hundreds of times in other tests and that “we have no reason to believe there’s an issue with the Super Dracos themselves.”
Propellants are fed to those engines by helium flowing from multiple high-pressure tanks, rapidly pushing fuel and oxidizer through a complex network of lines and valves. Some of the tanks survived the mishap and are still pressurized, preventing investigators from completing hardware recovery at the test site.
A SpaceX Falcon 9 rocket was spectacularly destroyed during a ground test in 2016 when a high-pressure helium tank, known as a carbon overwrap pressure vessel, or COPV, catastrophically ruptured. But Koenigsmann said the tanks used on the Crew Dragon were a different design and operate in a different environment. And all of them have been accounted for.
“We have tons of data, but we don’t have currently something we can say, oh, it was most likely this or that,” he said. “We do think, I think, it was not a Super Draco thruster itself, but that’s pretty much all I can say at this time.”
NASA and SpaceX had hoped to launch a different Crew Dragon in late July, carrying NASA astronauts Robert Behnken and Douglas Hurley on a test flight to the International Space Station. That mission would have been the first launch of U.S. astronauts aboard an American rocket from U.S. soil since the space shuttle was retired in 2011.
Boeing also is building commercial crew ships under contract to NASA with an initial piloted flight to the space station expected late this year or early next year.
“We did talk to Bob and Doug, of course,” Koenigsmann said, referring to Behnken and Hurley. “They were very sympathetic and reached out to us. I almost feel like they’re encouraging us right now, and they are helping us in keeping our motivation and not fall into a hole, basically, and get worked up over this, but rather stay focused.”
Against that backdrop, NASA and SpaceX are pressing ahead with plans to launch a Falcon 9 rocket early Friday on a flight to deliver nearly 5,500 pounds of equipment and supplies to the space station. The launch from pad 40 at the Air Force station is targeted for 3:11 a.m. EDT, the moment the Dragon cargo ship can be fired directly into the plane of the station’s orbit.
The cargo Dragon does not feature a Super Draco abort system and NASA managers agreed with SpaceX engineers that the launching could proceed.
“At the end of the day, we didn’t see any change in our overall measurable risk going into the mission,” said Kenny Todd, NASA manager of space station operations and integration. “We feel very comfortable moving forward with this particular mission.”
The cargo flight, the 17th for SpaceX under its current contract with NASA, originally was expected to launch earlier this week, but the mission was delayed when an electrical distribution box aboard the space station malfunctioned early Monday, taking down two of the lab’s eight solar power circuits.
The malfunction of main bus switching unit No. 3 also knocked out one of two circuits feeding the space station’s robot arm. Because the arm is used to capture and berth the cargo Dragon spacecraft, NASA opted to delay the launch until flight controllers could use the arm to install a spare unit.
That work was completed early Thursday, restoring redundant power to the robot arm and clearing the way for the Dragon’s launch Friday, weather permitting. Forecasters predicted a 60 percent chance of a launch delay due to thick clouds and rain, but conditions were expected to improve to 70 percent “go” Saturday.