NASA reported Monday that the scheduled launch of a SpaceX Crew Dragon spacecraft carrying four astronauts to the International Space Station on Wednesday has been delayed until at least Saturday due to a “minor medical concern” with one of the crew members.
The agency said that the delay is unrelated to COVID-19 and is not a medical emergency, but gave no other information. It is unknown which members of “Crew-3” — commander Raja Chari, pilot Thomas Marshburn, Kayla Barron, and European Space Agency astronaut Matthias Maurer — may be affected.
The astronauts were already quarantined, which is standard protocol for astronauts in the two weeks before launch, and there were no signs of a problem prior to NASA’s blog post statement.
“Teams will continue to monitor crew health as they evaluate potential launch opportunities at the end of the week,” the NASA statement said. “The earliest possible opportunity for launch is 11:36 p.m. EDT Saturday, Nov. 6.”
Unlike the Russian space agency, NASA does not select and train backup crews, so all four Crew-3 astronauts must be deemed fit before the flight can proceed.
The delay is the first for a piloted NASA mission due to a medical issue since space shuttle flight STS-36 in 1990 when commander John Creighton fell ill before launch.
The Crew-3 astronauts originally were scheduled for takeoff October 31, but launch was delayed to early Wednesday because of stormy weather in the Atlantic Ocean along the trajectory to orbit where the crew might be forced to make an emergency splashdown during an abort.
Given the nature of the lab’s orbit, the next opportunity to launch comes at 1:10 a.m. Wednesday, but NASA ruled that out with Monday’s announcement.
“The agency takes every effort to protect the crew prior to its launch through a health stabilization plan,” NASA said in its blog post. “Crew-3 astronauts will remain in quarantine at NASA’s Kennedy Space Center in Florida while preparing for their launch.”
The delay may have an impact on plans to bring four other space station astronauts back to Earth.
Launched aboard a Crew Dragon last April, the Crew-2 astronauts were planning on a “direct handover” with Chari, Marshburn, Barron and Maurer, helping their replacements get up to speed on station operations before heading back to Earth to close out a six-month stay in orbit.
But depending on how long the Crew-3 mission actually is delayed, the Crew-2 astronauts — commander Shane Kimbrough, pilot Megan McArthur, ESA astronaut Thomas Pesquet and Japanese flier Akihiko Hoshide — may be ordered home before their replacements get there.
That would temporarily leave the station in the hands of a reduced three-man crew, Soyuz MS-19/65S commander Anton Shkaplerov, cosmonaut Pyotr Dubrov and NASA astronaut Mark Vande Hei.
Shkaplerov was launched to the lab on October 5 while Dubrov and Vande Hei were launched in April and plan to spend nearly a full year in orbit before returning to Earth at the end of March.
Scientific highlights of the mission include an experiment to grow plants in space without soil or other growth media, and another to build optical fibers in microgravity, which prior research has suggested will be superior in quality to those made on Earth.
The Crew-3 astronauts will also conduct spacewalks to complete the upgrade of the station’s solar panels and will be present for two tourism missions, including Japanese visitors aboard a Russian Soyuz spacecraft at the end of the year and the Space-X Axiom crew, set for launch in February 2022.
Crew-2 had originally been set to return to Earth in early November, but NASA said Monday it would “continue to evaluate” possible dates for their return.
“Mission teams are reviewing options including both direct and indirect handovers for the upcoming crew rotation,” NASA said.