Four astronauts set for early Wednesday launch to space station
One day after bringing four commercial fliers down from the International Space Station, SpaceX prepared a Falcon 9 rocket and Crew Dragon capsule for launch early Wednesday to ferry four professional astronauts to the lab complex for a planned four-and-a-half-month stay.
Liftoff from pad 39A at the Kennedy Space Center is targeted for 3:52:55 a.m. EDT, roughly the moment Earth's rotation carries the rocket into the plane of the space station's orbit — a requirement for rendezvous missions. Forecasters predicted a 90% chance of good weather.
NASA's fourth operational commercial crew launch to the space station comes on the heels of a fully commercial flight to the outpost, an extended 17-day visit that came to an end Monday with a successful Atlantic Ocean splashdown.
Before pressing ahead with NASA's Crew-4 mission, engineers had to review data from the Axiom-1 mission to make sure no technical issues had cropped up that could affect downstream flights. As it turned out, "it was a very clean flight overall, really no major issues," said Steve Stich, manager of NASA's Commercial Crew Program.
"The teams have looked through a lot of the data," he said. "They've looked at the thermal protection system, they have looked at a lot of the (guidance, navigation and control) data from the flight. Obviously, the parachutes were very clean this flight. ... Early this morning, we had our launch readiness review and everybody polled 'go.'"
Crew-4 commander Kjell Lindgren, pilot Bob Hines, geologist-astronaut Jessica Watkins and European Space Agency astronaut Samantha Cristoforetti plan to strap in atop the Falcon 9 just after 1 a.m. Wednesday to await blastoff.
It will be the first rocket ride for Hines and Watkins. Lindgren and Cristoforetti are each veterans of a previous launch to the space station aboard Russian Soyuz spacecraft.
"Getting to fly to space is a once-in-a-lifetime opportunity," Lindgren said. "And to get to do it again is surreal. I know a little bit what to expect during launch. But for me, getting to launch from here, from the Kennedy Space Center, from a historic launch pad with an incredible legacy of exploration, is very, very meaningful."
Assuming an on-time launch, the Crew Dragon will catch up with the space station Wednesday night, moving in for docking at the Harmony module's space facing port around 8:15 p.m.
The 16-hour 22-minute rendezvous was timed to get the Crew Dragon to the station well before a planned Russian spacewalk Thursday. As it is, the SpaceX capsule will dock while the station's three cosmonauts are asleep.
Rather than waking them up early on the eve of a complex spacewalk, a traditional welcome-aboard ceremony for the Crew-4 astronauts will be delayed several hours until after the cosmonauts — Oleg Artemyev, Denis Matveev and Sergey Korsakov — get up to begin their busy day.
Lindgren's crew is replacing Crew-3 commander Raja Chari, pilot Thomas Marshburn, submariner-turned-astronaut Kayla Barron and European Space Agency astronaut Matthias Maurer, who launched to the space station last November.
Before heading home, the Crew-3 astronauts will familiarize their replacements with the ins and outs of station operations, reviewing safety procedures and on-going research. If all goes well, Chari and his crewmates will undock next Wednesday and return to Earth to close out a 174-day mission
The Crew-4 astronauts plan to remain aboard the station until mid-September when another Crew Dragon will bring up their replacements.