After an all-day review, NASA and SpaceX tentatively cleared a refurbishedand for launch next Thursday to ferry a three-man, one-woman crew to the International Space Station.
It will be the third piloted flight to orbit from U.S. soil since the shuttle's retirement in 2011 and the second operational Crew Dragon flight as NASA moves away from sole reliance on Russian Soyuz spacecraft to carry astronauts to and from low-Earth orbit.
Pending resolution of one presumably minor technical issue, liftoff from historic pad 39A at the Kennedy Space Center is targeted for 6:11 a.m. ET on April 22, which also happens to be Earth Day, kicking off a 23-hour rendezvous with the space station.
In Kazakhstan, meanwhile, Russian recovery crews and NASA support personnel were deployed for the planned re-entry and landing of a Soyuz spacecraft bringing three space station crew members back to Earth.
Soyuz MS-17/63S commander Sergey Ryzhikov, flight engineer Sergey Kud-Sverchkov and NASA astronaut Kate Rubins are scheduled to undock from the lab complex at 9:34 p.m. ET Friday, setting up a landing on the steppe of Kazakhstan at 12:56 a.m. Saturday (10:56 a.m. local time).
The landing will come just six days after another Soyuz reached the space station carrying three fresh crew members: Soyuz MS-18/64S commander Oleg Novitskiy, flight engineer Pyotr Dubrov and NASA astronaut Mark Vande Hei.
The two Soyuz crew rotation flights set the stage for the SpaceX Crew Dragon launch Thursday and the return to Earth of another Crew Dragon on April 28, bringing four astronauts home after a 164-day stay in space.
During a formal flight readiness review at the Kennedy Space Center, senior managers agreed to press ahead with launch of the SpaceX "Crew-2" astronauts next week and the return of the four Crew-1 station fliers they are replacing.
"This was an important milestone today because this is when the teams come together ... and we put that stamp of approval that it's safe for our astronauts to get on the vehicle and launch, and, in the case of Crew-1, come home safely," said Norm Knight, deputy director of flight operations at the Johnson Space Center.
The Crew-2 Falcon 9 rocket, featuring the same first stage that launched the first operational Crew Dragon mission — Crew-1 — in November, was expected to be hauled out of SpaceX's hangar at the base of pad 39A overnight Thursday.
Crew-2 commander Shane Kimbrough, co-pilot Megan McArthur, European Space Agency astronaut Thomas Pesquet and Japanese flier Akihiko Hoshide, all space veterans, are expected to fly to the Florida spaceport Friday afternoon to begin final launch preparations.
SpaceX engineers plan to test fire the Falcon 9's first stage engines Saturday morning and carry out a dress rehearsal countdown with the astronauts early Sunday. The test firing and dress rehearsal are both timed to mimic actual launch day procedures and timing.
Only one issue remains under review going into a busy weekend.
Bill Gerstenmaier, NASA's former director of spaceflight operations and now a SpaceX vice president, said engineers recently discovered that slightly more liquid oxygen propellant was routinely being pumped into Falcon 9 first stage tanks before launch than they had realized.
The difference only amounts to a few extra inches in the tank's load of super-chilled oxygen, but engineers want to make sure they understand the discrepancy and what impacts, if any, it might have on performance or safety.
Assuming an on-time launch Thursday, the Crew-2 astronauts will dock at the station's forward port next Friday morning, April 23.
They will be welcomed aboard by space station commander Shannon Walker and fellow Crew-1 astronauts Michael Hopkins, Victor Glover and Japanese astronaut Soichi Noguchi, along with Novitskiy, Dubrov and Vande Hei.
After a weeklong "handover" to help familiarize their replacements with station operations, the Crew-1 astronauts will depart, riding their SpaceX capsule to a splashdown in the Gulf of Mexico south of Tallahassee, Florida, around 12:40 p.m. ET on April 28.
Before departing, Walker will turn over command of the station to Hoshide, who will be in charge during the.
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