WASHINGTON — A Falcon 9 launched a multinational crew to the International Space Station Aug. 26 after a one-day delay to envision the spacecraft’s life support system.
The SpaceX Falcon 9 lifted off from Launch Complex 39A on the Kennedy Space Center at 3:27 a.m. Eastern on the Crew-7 mission for NASA. The Crew Dragon spacecraft Endurance separated from the Falcon 9’s upper stage slightly greater than 12 minutes later.
Endurance, with its crew of 4, is scheduled to dock with the zenith port on the Harmony module of the ISS at 8:39 a.m. Eastern Aug. 27. That can kick off a roughly six-month stay on the station.
The launch was scheduled for Aug. 25 but postponed several hours before the scheduled liftoff. NASA said that engineers needed more time to review a component of the Crew Dragon’s life support system, often called ECLSS. NASA didn’t initially state what that component was but later said it was valves in an air supply system.
Steve Stich, NASA industrial crew program manager, said on the post-launch briefing that after discovering corroded valves within the propulsion system of a cargo Dragon in June, SpaceX “out of an abundance of caution” decided to review all valves on the spacecraft, including for all times support and propulsion. The review was designed to envision the “force margin,” or the power of the valve to open and shut.
“It took slightly bit more time to get through the ECLSS valves,” he said, which led to the one-day slip. “We said, let’s stand down for twenty-four hours and be sure that we understand it before we go fly.” That review confirmed that the valves were working properly and required no changes.
Through the launch countdown, controllers reported a sensor issue that was cleared shortly before liftoff. On the post-launch briefing, officials said that sensors had detected trace amounts of nitrogen tetroxide, or NTO, from the Crew Dragon spacecraft that indicated a possible propellant leak. NTO is certainly one of the 2 hypergolic propellants utilized by the spacecraft’s thrusters.
Benji Reed, senior director of the human spaceflight program at SpaceX, said on the post-launch briefing that the degrees of NTO detected were about 0.25 parts per million. Three engineers independently calculated what level of leak could cause that reading and all three got here to the identical conclusion. “The excellent news was that the number that we got here up with was well throughout the range of what you may normally see.”
That assessment, though, got here right down to the wire. “We were working the issue and we cleared it throughout the last two minutes of the count,” he said.
Crew-7 is the primary industrial crew flight to hold people from 4 different agencies. The mission is commanded by NASA astronaut Jasmin Moghbeli on her first flight to space. European Space Agency astronaut Andreas Mogensen is the pilot; he made a 10-day trip to the station on a Soyuz spacecraft in 2015. Satoshi Furukawa of the Japanese space agency JAXA and Roscosmos cosmonaut Konstantin Borisov are mission specialists. Furukawa flew a long-duration mission to the ISS in 2011 while Borisov is on his first trip to space.
That multinational lineup was simply how the crew assignments worked out, said Joel Montalbano, NASA ISS program manager, at a preflight briefing Aug. 21. “The way in which the timing worked out for this one with our integrated crew agreement that we’ve got with Roscosmos, it was time for these other people to fly,” he said.
Stich said at that briefing that one other milestone for Crew-7 is having a non-NASA astronaut, Mogensen, be a Crew Dragon pilot for the primary time. “It’s a really big deal for us,” he said then.
Such multinational crews is not going to all the time be the case. The subsequent Crew Dragon mission to the ISS, Crew-8 launching in early 2024, can have three NASA astronauts and one Roscosmos cosmonaut.
The arrival of Crew-7 will allow NASA to start preparations for the return of the Crew-6 mission, which has been on the station for nearly six months. Montalbano said on the post-launch briefing that the agency was planning a five-day handover between Crew-6 and Crew-7 before Crew-6 departs on the Crew Dragon spacecraft Endeavour. That timing, though, will rely upon weather at splashdown locations off the Florida coast, which could possibly be affected by the expected formation of a tropical storm within the Gulf of Mexico in the following several days.