SpaceX launches four astronauts into Earth orbit on Friday.
The company’s Crew Dragon spacecraft is the first and only commercial vehicle carrying astronauts into space. It is now a routine part of NASA’s human space travel program.
Friday’s mission, called Crew-2, is the second of six manned spaceflight the agency has hired from SpaceX. NASA officials gave SpaceX a green light for launch on Tuesday after two in-depth reviews of the rocket, spacecraft and launch preparations.
“We’ve completed thousands and thousands of tests to get to this day, just as we’ve always done in the past and will continue to do,” Benji Reed, senior director of SpaceX’s Human Spaceflight Programs, said at a news conference Tuesday.
“We want to be paranoid, don’t we?” he added. “We want to make sure we fly these people safely and be able to bring them home safely when the time comes. So we check. We check under every rock and we check double and triple check.”
The four Crew-2 astronauts – Shane Kimbrough and Megan McArthur of NASA, Akihiko Hoshide of the Japanese Aerospace Research Agency and Thomas Pesquet of the European Space Agency – will climb on the Crew Dragon’s capsule early Friday morning, and then rocket into the space. is 5:49 am ET.
The spacecraft must reach orbit, dock at the International Space Station (ISS), and remain there for about six months while the astronauts work in the orbit laboratory. Then it has to bring them back safely.
The astronauts will fit in early Friday morning
Launch day begins early for the Crew-2 astronauts, who will put on their SpaceX spacecraft around 2 p.m. ET. Then they will say goodbye to their families, get into a pair of regular Teslas and head off to Launch Complex 39A.
“We always ask ourselves: Would we want to fly our families with these vehicles?” Reed said.
They will join a recycled spacecraft around 3:15 am ET
Early Friday, the Crew-2 astronauts will climb the launch tower and climb onto the Crew Dragon capsule called Endeavor.
McArthur’s husband, Bob Behnken, piloted the first manned SpaceX flight in that same capsule last year. A demonstration mission called Demo-2 led him and astronaut Doug Hurley to the ISS for three months.
Like her husband, McArthur will pilot Effort for her mission.
“I’ll launch on the same seat. So that’s kind of a fun thing we can share, you know, I can tease him and say, ‘Hey, can you hand over the keys? I’m ready to go now,'” McArthur just said. in a press call.
The rocket is loaded with fuse immediately before takeoff
Thirty-five minutes before takeoff, at 5:14 am ET, technicians will begin remotely charging the Falcon 9 rocket with kerosene and a cryogenically cooled liquid-oxygen fuse.
The rocket accelerator that will push Crew-2 into space has also been recycled. It is the same one that launched the Crew-1 mission in November.
“Flying on re-used vehicles, on air-tested vehicles, is key to greater flight reliability and a decrease in the cost of access to space, which ultimately helps us make life multi-planetary,” Reed said.
Reusability, he added, is “the holy grail of space travel.”
Going time is exactly two seconds after 5:49 am
When the countdown clock reaches zero – exactly two seconds after 5:49 am ET – the Falcon 9 engines will start, raising the rocket past the launch pad.
The astronauts will be pressed into their seats for about 10 minutes while the vehicle screams into space. Then the rocket accelerator must fall – to land on Earth and launch another day – giving the Crew Dragon one final push into Earth’s orbit.
Lifting is immediate, meaning it must occur at the exact second at which it is scheduled. Expectation would allow the ultra-cold fuse to heat up, expand and boil – reducing the thrust of the engines and inviting risks that NASA doesn’t want to take with people on board.
But for takeoff, the sky must be clear and winds must be low around the launch pad. Friday’s launch was originally scheduled for Thursday, but NASA rejected it due to a disadvantageous forecast.
NASA also monitors weather conditions for a group of landing sites across the Atlantic. If something goes wrong during launch, the Crew Dragon automatically dumps the Falcon 9 rocket and parachutes into the sea. So winds and waves need to be gentle at those locations, and SpaceX recovery teams need to be ready to rush wherever the Endeavor capsule lands.
If weather is bad at the launch sites or splash sites, NASA and SpaceX will rub the launch and try again on Monday.
The Crew Dragon will dock at the space station on Saturday
After the Crew Dragon glides into orbit, it will remain there for nearly 24 hours. The astronauts are likely to change out of their spacesuits, eat, sleep completely, have breakfast, organize their belongings, and eventually put on their spacesuits to prepare for arrival on the ISS.
SpaceX and NASA expect the Crew Dragon to perform a series of automatic maneuvers to dock at the ISS around 5:10 a.m. Saturday. The astronauts must be fit if something goes wrong and the Crew Dragon must return to Earth prematurely.
Crew-1 will return to Earth shortly after Crew-2’s arrival
The ISS will be full of 11 astronauts for at least four days as the Crew-2 mission overlaps with Crew-1, the first functional SpaceX mission.
As early as April 28, the Crew-1 astronauts – Shannon Walker, Victor Glover, Mike Hopkins and Soichi Noguchi – will climb back on their own Crew Dragon capsule.
That capsule, called Resilience, will then slip out of the ISS, push itself to Earth and dive through the atmosphere. Parachutes must be released, allowing the spacecraft to drift to a landing off the coast of Florida.
A recovery crew will wait to retrieve the burned Resistance capsule and carry the astronauts to shore. SpaceX, NASA and the Coast Guard plan to secure a 10-mile unobstructed perimeter around the splash site to prevent the crowd of dangerously close spectators who surrounded Demo-2 when that capsule landed.
Crew-2 will remain on the ISS for 6 months
The Crew-2 astronauts will remain on the ISS for about six months, running the station, making repairs and doing scientific research. They will return to Earth with their own fall in autumn.
Crew Dragon Missions is the fruit of NASA’s Business Crew Program, which the Obama administration funded in 2010 to restore the agency’s human space travel capabilities. Through this program, NASA worked with SpaceX to make the Dragon spacecraft and Falcon 9 capable of safely transporting humans. Their missions restored U.S. human space travel for the first time since the space shuttle ended in 2011.
Boeing has also developed a spacecraft with the Merchant Crew Program, but it must remake an unmanned test flight to the ISS before it can carry anyone into space.