Crew-1, which launched to the space station in November, will head home in the capsule called Resilience.
Four astronauts are taking the redeye home to Earth.
At 8:35 p.m. Eastern time on Saturday, a crew of four — three NASA astronauts and one from Japan’s space agency — pushed off from the International Space Station in a capsule built by SpaceX.
“Thanks for your hospitality, sorry we stayed a little bit longer,” said Michael Hopkins, the Crew Dragon Resilience’s commander, referring to the weather-delayed departure of the flight. “We’ll see you back on Earth.”
The astronauts will circle the planet a number of times over the hours that follow until they splash down early on Sunday morning in the Gulf of Mexico south of Panama City, Fla.
NASA has not conducted a nighttime splash down like this since 1968, when Apollo 8, the first mission to send astronauts around the moon, returned to Earth.
Here’s what you need to know:
When will the astronauts splash down on Earth?
The approximate timing of the splash down is 2:57 a.m. Eastern time on Sunday. SpaceX in an update on Saturday afternoon reported that the weather continued to be favorable for a landing.
The agency has scheduled a news conference with NASA, SpaceX and other officials for 5 a.m. on Sunday.
NASA and SpaceX are streaming live coverage of these operations on NASA TV or you can watch the video in the player embedded above.
What happens during the astronauts’ trip home?
It’ll be a long trip. The astronauts boarded the Crew Dragon and the hatch closed at 6:26 p.m., but then more than two hours passed before the capsule left as the astronauts checked that there were no air leaks from either the capsule, named Resilience, or the space station. Resilience autonomously undocked at 8:35 p.m. and then performed a series of thruster firings to move away from the space station.
SpaceX confirmed that the thruster firings were completed at 10:17 p.m. The capsule will now circle the plant until Florida lines up in the correct position for it to splash down in the Gulf of Mexico.
Just before 2 a.m., as it prepares for its return to Earth, the Crew Dragon will jettison what SpaceX calls the “trunk” section of the spacecraft — the cylindrical compartment below the gumpdrop-shaped capsule. The trunk will burn up in the atmosphere.
Five minutes after the trunk is detached, the capsule will fire its thrusters to drop out of orbit.
Once it is low enough in Earth’s atmosphere, parachutes will deploy to gently lower the capsule into the sea.
What do astronauts experience during a water landing?
Spacecraft can safely return to Earth on water or land.
During the 1960s and 1970s, NASA’s Mercury, Gemini and Apollo capsules all splashed down in the ocean while Soviet capsules all ended their trips on land. Russia’s current Soyuz capsules continue to make ground landings, as do China’s astronaut-carrying Shenzhou capsules.
NASA returned to water landings on Aug. 2, 2020, when the first crew returning to Earth in a SpaceX Crew Dragon capsule — the same one that carried astronauts to the space station last week — splashed down near Pensacola, Fla.
Returning from the free-fall environment of orbit to the normal forces of gravity on Earth is often disorienting for astronauts. A water landing adds the possibility of seasickness.
During a news conference last year, Douglas Hurley, a member of the earlier crew that completed a water landing in the SpaceX capsule, said he had read reports by astronauts from NASA’s Skylab missions, some of the last before him to do water landings. “There was some challenges post-splashdown,” he said. “Folks didn’t feel well, and you know, that is the way it is with a water landing, even if you’re not deconditioned like we’re going to be.”
Mr. Hurley acknowledged that vomiting would not be unexpected.
“There are bags if you need them, and we’ll have those handy,” he said. He added that “if that needs to happen, it certainly wouldn’t be the first time that that’s happened in a space vehicle.”
Is it safe to land in the ocean at night?
American spacecraft have not carried out a nighttime water landing by astronauts since Apollo 8, NASA says.
That crew arrived before dawn on Dec. 27, 1968, about 1,000 miles southwest of Hawaii. The Times the next day called it “a pinpoint splashdown” and noted that the crew stayed in their capsule for about 90 minutes before they were fished out of the Pacific Ocean by a helicopter team from the U.S.S. Yorktown. William Anders, the mission’s lunar module pilot, said over the radio while in the capsule, “Get us out of here, I’m not the sailor on this boat.” (James Lovell, his crew mate, had been a captain in the U.S. Navy.)
SpaceX has rehearsed working at night, and in January it successfully recovered a cargo capsule that splashed down in the Gulf of Mexico, west of Tampa Bay.
One advantage of a nighttime landing could be that fewer private boats are likely to be around. That was a problem in August when the earlier SpaceX capsule splashed down. More than a dozen boats — one of them flying a Trump campaign flag — converged on the singed capsule, and a few went in for a closer look.
The episode raised concerns among NASA and SpaceX officials about security and safety procedures. If there had been an emergency, NASA officials said, the private boats might have impeded recovery efforts. They added that there could have been poisonous fumes from the capsule that posed a risk to the boaters.
To avert such an outcome, the Coast Guard this time will set up a 11.5-mile safety zone around splashdown site and chase away any interlopers.
What is the space debris risk to the astronauts?
Typically, the risk of space junk hitting a spacecraft going to or from the space station is small. It is generally a pretty short trip — about a day — and a spacecraft like Crew Dragon is pretty small, so it’s not a big target for a wayward piece of debris.
But when another group of astronauts, Crew-2, launched last week in a different Crew Dragon, they had a bit of a scare when mission control at SpaceX headquarters in California told them that there was a piece of debris headed their way. They put their spacesuits back on and got back in their seats just in case the spacecraft was hit, which could cause depressurization of the capsule.
Mission control then provided a reassuring update: Further analysis indicated the closest approach of the space debris was not that close after all. Still, as a precaution, the astronauts waited until they were told that the space junk had passed by.
The next day, a NASA spokesman said the debris had passed by at a distance of 28 miles — not very close at all.
Then, the United States Space Command, which tracks orbiting debris, made a more perplexing update: The piece of debris that supposedly passed by the Crew Dragon never existed at all. A Space Command spokeswoman said a review was underway to determine what caused the spurious warning.
Who are the astronauts?
There are four astronauts on Crew-1:
Victor Glover, 45, selected by NASA in 2013 to be an astronaut, is on his first spaceflight. He is also the first Black NASA astronaut to be a member of a space station crew.
Michael S. Hopkins, 52, a colonel in the United States Space Force, is the commander for the flight. (Colonel Hopkins is also the first member of the newly created U.S. Space Force to go to space.) He was one of nine astronauts selected by NASA in 2009. He has made one previous trip to the International Space Station, in 2013-14, spending 166 days in orbit.
Soichi Noguchi, 56, an astronaut with JAXA, the Japanese space agency, is completing his third trip to space. He was a member of the crew of the space shuttle Discovery in 2005, on the first shuttle launch after the loss of Columbia and its seven astronauts more than two years earlier.
During that visit to the International Space Station, Mr. Noguchi made three spacewalks. That included one to test techniques developed to repair damage to the heat tiles on the shuttle similar to what had doomed Columbia when it re-entered Earth’s atmosphere. In 2009-10, he spent five months in orbit as a member of the space station crew.
Shannon Walker, 55, has had one previous stint on the space station, in 2010. Dr. Walker has a doctoral degree in space physics from Rice University, where she studied how the solar wind interacted with the atmosphere of Venus.
What have the astronauts been doing aboard the space station?
The space station has been a bit more crowded than usual since another SpaceX Crew Dragon capsule, Endeavour, docked on Saturday, April 24. That brought the station’s crew tally to 11, the largest number of astronauts on board since the space shuttles stopped flying (the record for most on board is 13). The four astronauts are leaving seven astronauts behind — three from NASA, two from the Russian space agency Roscosmos, one from the European Space Agency and one from JAXA.
But while they were there, they conducted science experiments including tissue chips that mimic human organs and grew radishes and other vegetables. They also performed spacewalks to install equipment on the outside of the space station, including to prepare it for new solar panels.
And just before they left, Mr. Glover celebrated his 45th birthday in orbit.
Other astronauts were also savoring their final moments in orbit with images posted on Twitter.
What happens after a safe landing?
If the landing is similar to the return last August, SpaceX personnel will go to the capsule, check that it is intact and not leaking any toxic propellant and recover the parachutes.
A larger recovery ship will pull the capsule out of the water. The hatch is then opened for the four astronauts to get out.
After medical checks, the astronauts will head to shore. From there, they will fly to Houston. The capsule will be taken to Cape Canaveral, where it will be refurbished for another flight to space.
https://ift.tt/334xSTd
Science
No comments:
Post a Comment