SpaceX rolled a reused Falcon 9 booster and a brand new Dragon crew capsule to their launch pad for final tests Tuesday at the Kennedy Space Center in Florida, a day after the astronauts who will ride the spacecraft to the space station arrived for pre-flight preparations.
Ground teams transported the rocket and Dragon spacecraft the quarter-mile distance from SpaceX’s hangar up the ramp to pad 39A Tuesday morning, then raised the 215-foot-tall (65-meter) vehicle vertical in the afternoon. A test-firing of the Falcon 9’s main engines is scheduled for Wednesday morning, leading to launch of NASA’s Crew-4 mission to the International Space Station no earlier than Saturday.
The launch will be SpaceX’s seventh human spaceflight mission, and the fourth operational crew rotation flight to the space station under contract with NASA. SpaceX’s other crew missions have included a test flight for NASA in 2020, and two purely commercial flights — the Inspiration4 mission last September and the Axiom private astronaut mission currently at the International Space Station.
The Falcon 9 booster for the Crew-4 mission will be flying for the fourth time. The rocket stage — designated B1067 — previously launched a Dragon cargo mission, NASA’s Crew-3 astronaut flight, and the Turksat 5B communications satellite last year.
The booster originally assigned to the Crew-4 mission — tail number B1069 — was damaged during a landing attempt on a SpaceX drone ship Dec. 21.
“NASA and SpaceX jointly select primary and backup first stage boosters ahead of each crewed mission,” a NASA spokesperson said. “We jointly agreed to use the back-up booster for Crew-4 following an asymmetrical landing of the originally planned booster due to high sea states.”
The Crew Dragon spacecraft awaiting launch on top of the Falcon 9 rocket is the fourth, and likely final, reusable Dragon crew capsule to join SpaceX’s fleet. The Dragon Freedom spacecraft joins Endeavour, Resilience, and Endurance in SpaceX’s rotation of crew capsules.
Meanwhile, the four astronauts assigned to the Crew-4 mission jetted into the Kennedy Space Center on Monday from their home base at the Johnson Space Center in Houston.
Commander Kjell Lindgren, pilot Bob Hines, and mission specialists Jessica Watkins and Samantha Cristoforetti will launch on the Crew-4 mission for a planned stay of approximately five months at the International Space Station.
Lindgren, veteran of a previous launch on a Russian Soyuz rocket, said: “I feel like getting to fly to space is a once in a lifetime opportunity, and to get to do it again is surreal and such a privilege.
“I have a sense that I know a little bit what to expect during a launch, but for me, getting to launch from here, from Kennedy Space Center, from a historic launch pad with an incredible legacy of exploration is very, very meaningful for me.”
The launch preparations for the Crew-4 mission come amid a busy stretch of spaceflight activities for NASA and SpaceX. Two Dragon crew capsules are currently docked at the International Space Station — one for Axiom Space’s private astronaut mission and one for the Crew-3 mission to be replaced by the Crew-4 astronauts.
Axiom’s four-man Ax-1 mission was scheduled to depart the space station Tuesday and head for splashdown off the coast of Florida, but the departure was postponed due to bad weather in the recovery zones in the Gulf of Mexico and the Atlantic Ocean. The Crew-4 launch will wait until the Ax-1 mission is back on Earth, and it wasn’t clear Tuesday how the Crew-4 schedule might be impacted the Ax-1 landing delay.
Once the Crew-4 mission is docked at the station, Lindgren and his fresh crewmates will work with the four outgoing Crew-3 astronauts in a handover lasting up to one week. Then Crew-3 will undock and come back to Earth, a return tentatively scheduled for April 30, assuming Crew-4 launches this weekend.
Watkins, a geologist and the youngest member of the crew, will become the first Black woman on a long-duration mission at the space station.
“I am just really honored to be part of the long legacy of Black astronauts and Black women astronauts who came before me,” she said Monday.
The Crew-4 astronauts will spend their last few days before launch reviewing their flight plan, going through a countdown dress rehearsal, and spending time with friends and family.
“I plan to take a very long luxurious shower on that last day before launch,” said Cristoforetti, an Italian-born European Space Agency astronaut.
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