WASHINGTON – A first phase of Falcon 9 could not land last month because one of its engines shut down during flight after hot gas broke a worn lid.
Speaking at a NASA press conference on March 1 about the upcoming Crew-2 commercial crew flight, Benji Reed, senior director of human spaceflight programs at SpaceX, said that while the booster used at the February 15 launch made its sixth flight , some components it was ‘life leaders’ who flew more frequently than any other in the Falcon 9 fleet.
This initially included ‘boots’ or lids around parts of the Merlin engines. “It was the highest number of flights this particular suitcase design has seen,” he said.
However, one of those boots had a ‘little hole’ that made it possible for hot gas to get into parts of the engine during the flight, he said. ” A bit of hot gas came where it should not have been, and that caused the engine to shut down, ” he said.
Reed did not mention at what point the engine started, but he suggested that it occurred during takeoff. ” A great thing about Falcon 9 is that we have a car-out capability, ” he said, meaning one of the nine first-phase engines can shut down without jeopardizing the mission. ‘The vehicle pulled around the orbit and placed the satellites exactly where they wanted to be. The primary mission was accomplished. ”
However, the shutdown of the engine prevented the first phase from landing. “When the booster came back home, due to the problem with the specific engine, we did not have enough power to get back to where we needed to be, and we did not land where we wanted to be,” he said.
Reed’s comments so far have provided the most details on why the booster failed to land, breaking a streak of two dozen consecutive landings almost a year ago. Hans Koenigsmann, a long-time SpaceX CEO who is currently a senior adviser on building and flight reliability at the company, said on February 23 that “heat damage” should be blamed, but did not elaborate.
The Falcon 9 has not been launched since the February 15 mission, although the company tried to launch another set of Starlink satellites on February 28. The launch was scrubbed 84 seconds before the scheduled eastern lifting of 20:37, and the company did not set a new date for the launch or provide more information on the cause of the scrub.
During the webcast of the launch attempt, the SpaceX hosts did not discuss the failed landing. However, they noted that from the first phase of the launch, there would be no video, a break with the company’s standard practices.
Reed said the engine problem is a “good lesson we learned” as the company better understands the lifespan of Falcon 9 amplifiers and which components are most susceptible to wear and tear. The company is also working on upgrading control systems on the vehicle “to further detect and control what the vehicle needs to do” in such circumstances.
NASA has been following the investigation to understand if there are any issues with the Falcon 9 that will launch the Crew-2 mission, which is currently not planned until April 20th. “We will follow the SpaceX investigation,” Steve Stich, director of the NASA Commercial Crew Program, said during the briefing that he made sure they understood the problem before launching the mission.
A major difference between the Starlink missions and Crew-2 is the number of flights. “We are about to tackle our first reuse for a crew vehicle here,” he said. The Falcon 9 amplifier launched by Crew-2 previously launched the Crew-1 mission in November 2020, but with no flights in between. “SpaceX Starlink flights are pretty far out there” in terms of the number of reusers of the boosters, he noted.
The astronauts who will be flying on Crew-2 have also kept up with these and possibly other Falcon 9 issues. “We are informed every month about the updates of our spacecraft as well as the rocket, so we are very confident that they will notice what is going wrong.” says Shane Kimbrough, the NASA astronaut who will lead Crew-2. “It was just a few little things on some of these rockets.” He did not elaborate on what the ‘few little things’ are.