Weather could postpone Crew Dragon return
WASHINGTON — NASA and SpaceX are ready to wrap up a test flight of the company’s Crew Dragon spacecraft, but poor weather could delay the return of the spacecraft and its two-person crew.
A July 29 “return flight readiness review” by NASA approved plans to wrap up the Demo-2 test flight and bring NASA astronauts Bob Behnken and Doug Hurley back to Earth, a little more than two months after their launch to the International Space Station.
The earliest possible undocking of the Crew Dragon is about 7:35 p.m. Eastern Aug. 1, which would set up a splashdown off the Florida coast at 2:48 p.m. Eastern Aug. 2, said Steve Stich, NASA commercial crew program manager, at a briefing after the review.
That schedule assumes that weather conditions will be favorable for a landing. However, Tropical Storm Isaias is projected to reach Florida Aug. 2. While not forecast to become a hurricane, its winds and rain could postpone a landing.
Even without a threatening tropical storm, NASA said they will have to closely watch weather conditions given the stringent limits for this test flight. “The one that may be the most challenging is wind,” Stich said, with a limit of about 16 kilometers per hour. “This is to protect how the vehicle actually lands in the water and how the water will come up and surround the vehicle at touchdown.”
There are also limits on sea state, including wave height and period, as well as rain. Stich said the goal is to have acceptable weather conditions forecast for at least two of the seven splashdown locations before proceeding with the undocking. Once Crew Dragon undocks, it has enough supplies to remain in orbit for three days.
If weather postpones the first landing opportunity, Stich said the next opportunity to undock would be Aug. 3. “We’ll take it day by day,” he said. “We’ll evaluate the weather each day and see how the weather unfolds.”
The undocking and splashdown will wrap up a mission that both NASA and SpaceX said they’ve been pleased with to date. The Crew Dragon launched on a Falcon 9 May 30 and docked with the ISS the next day. While at the station, engineers have been monitoring its performance and performing various tests, including one where four station crew members boarded the capsule to see how it performs with a full crew complement.
“The systems on Dragon are doing very well. The spacecraft is very healthy,” Stich said. That included an inspection of the spacecraft last weekend by the station’s robotic arm, which saw no evidence of any damage or other issues that would pose a problem for the upcoming return.
Once the spacecraft returns, NASA and SpaceX will inspect the spacecraft and review data as part of a process that will culminate with a formal NASA certification of the spacecraft for operational flights. “Going through that process, leading to certification, takes about six weeks,” Stich said.
That certification will allow that first operational mission, Crew-1, to proceed with a launch scheduled for late September. The Crew Dragon spacecraft that will fly that mission is nearing completion at SpaceX’s Hawthorne, California, factory and will ship to Florida in early August, said Benji Reed, director of crew mission management at SpaceX.
The Demo-2 capsule will be refurbished for use on the Crew-2 mission, which will launch in the spring of 2021. NASA announced July 28 the crew for that mission, which includes NASA astronauts Shane Kimbrough and Megan McArthur along with Akihiko Hoshide of the Japanese space agency JAXA and Thomas Pesquet of the European Space Agency.
Reed said that refurbishing the Crew Dragon should be a “very fast process” that can be done at a Florida facility, with the capsule ready for its next mission within a couple of months. Each Crew Dragon spacecraft is designed for at least five flights.
SpaceX won approval from NASA in May to start reusing both the Crew Dragon spacecraft and the first stages of Falcon 9 rockets on commercial crew missions, starting with Crew-2. The company originally proposed flying a new spacecraft on each NASA mission.
“We’ve continued over the last number of years proving the awesomeness of reuse and reflight, and the importance of it,” Reed said of the decision to reuse Crew Dragon spacecraft, noting its advantages not just in economics but also safety and reliability. “We were always ready to do it, and it was always part of the plan.”