WASHINGTON — NASA and SpaceX are proceeding with a commercial crew mission to the International Space Station later this week, part of a busy schedule of missions to the station this year.
NASA completed a flight readiness review Feb. 25 for the Crew-8 mission to the ISS, announcing late in the day that the agency had approved plans for the launch, scheduled for 12:04 a.m. Eastern March 1 from the Kennedy Space Center. That would allow the Crew Dragon spacecraft to dock with the station at approximately 7 a.m. Eastern March 2.
Crew-8 is the latest crew rotation mission to the station. It will carry NASA astronauts Matthew Dominick, Michael Barratt and Jeanette Epps, and Roscosmos cosmonaut Alexander Grebenkin, to the station for a six-month stay. The flight will be the first for all but Barrett, who will be making his third flight and second long-duration stay on the ISS.
At a media briefing after the fight readiness review, NASA and SpaceX officials said they were working on a few minor technical issues with the Crew Dragon spacecraft and Falcon 9 rocket. That includes confirming composite panels on the vehicle are properly fastened and studying paint discoloration seen on the Crew-7 Crew Dragon currently at the station that could change the vehicle’s thermal properties on reentry, said Steve Stich, NASA commercial crew program manager.
Those open items, he said, did not appear to be major issues. “I suspect we’ll close these out Tuesday or Wednesday.”
One previous issue that appears to be resolved involved straps in the main parachutes called “energy modulators” intended to regulate the load on the parachutes as they are extracted from the capsule. Some of those straps did not pull apart as designed on a cargo Dragon mission, CRS-29, that returned in December.
Those straps worked as intended on the most recent Crew Dragon flight, the Ax-3 private astronaut mission that splashed down Feb. 9. “We didn’t see any of the energy modulator problems that we’ve seen on previous flights,” said Bill Gerstenmaier, SpaceX vice president of build and flight reliability.
The flight will be the fifth for this Crew Dragon spacecraft, named Endeavour, which flew the first crewed SpaceX mission, Demo-2, in 2020. NASA has currently certified Crew Dragon for five flights, but is working with SpaceX to extend that certification to as many as 15 flights.
“We’re in the middle of doing that work,” Stich said, evaluating various vehicle components. “Some are actually approved for 15 flights, some we’re still in the middle of working on.”
He said that work might result in extending the lifetime of Crew Dragon, as well as its cargo variant, to some intermediate value between 5 and 15 flights, at least initially. “I would like to get out to 7 to 10 flights per Dragon, but we’ll see where we get to.”
SpaceX is also completing a fifth Crew Dragon spacecraft. Gerstenmaier said that vehicle would be ready this fall, with it notionally planned to fly the Crew-10 mission in 2025. “Whenever NASA wants to go ahead and use that vehicle, it will be available sometime in the fourth quarter of this year.”
Preparing for Starliner
Also waiting in the wings is Boeing’s CST-100 Starliner commercial crew vehicle, slated to make its long-delayed first crewed flight this spring. The Crew Flight Test (CFT) mission, with NASA astronauts Butch Wilmore and Suni Williams on board, is currently scheduled for launch April 22, Stich said.
“We’ve worked through a number of issues that delayed the launch from last summer and closed those out,” he said. That included a final parachute test in early January to confirm changes in the design intended to increase its strength. That test was a success, he said, with no additional parachute tests planned before the CFT launch.
Workers have also replaced flammable tape in the Starliner spacecraft and resolved in-flight anomalies from the OFT-2 uncrewed test flight in May 2022. “Right now things are looking good for, towards the end of April, launching Starliner.”
That launch will fit into a busy schedule of missions to the ISS. The Crew-7 Crew Dragon mission is scheduled to undock no earlier than March 8, he said. That will free up a docking port for a cargo Dragon mission, CRS-30, scheduled to launch in mid-March. It will remain on the station for about a month, and after undocking the Crew-8 Crew Dragon will move from the forward to the zenith docking ports to allow Starliner to dock at the forward port.
“Some future launch date adjustments for even Starliner might happen just because of this busy timeframe,” Stich said.
Launching from Pad 40
The CRS-30 mission is currently scheduled to launch from Space Launch Complex (SLC) 40, and will be the first mission to make use of the crew and cargo access tower that SpaceX built at the pad. That will allow SLC-40 to host Dragon missions that currently can only launch from Launch Complex 39A.
“We’ve got a good plan laid out to get everything certified and ready to go fly for that time,” Gerstenmaier said. “We’ll be in good shape for CRS-30.”
Having the ability to launch Dragon missions from SLC-40 will provide some redundancy should there be problems with LC-39A. It would also help address launch pad congestion issues, since LC-39A is designed to support Falcon Heavy launches as well. SpaceX further modified LC-39A to allow Intuitive Machines’ lunar landers to be fueled with liquid oxygen and methane propellants shortly before launch.
That meant that Crew-8 was delayed slightly to accommodate the IM-1 mission that launched Feb. 15. “We were trying to sort of thread a needle,” Stich said, finding a launch date for Crew-8 that came after the February launch window for IM-1 but also before a March window had IM-1 slipped. “We adjusted our date a few different times to protect as many options as we could.”
That resulted in about a one-week delay for Crew-8, which is also launching from LC-39A. “Who would have thought, five or six years ago, that the competition for launch, or the constraint to launch, would be a launch pad?” Dominick, the commander of Crew-8, said in remarks after arriving at the Kennedy Space Center Feb. 25. “We delayed our launch a few days because there’s stiff competition to get out there to 39A. It’s not a rocket constraint, it’s a pad constraint.”
