If a hurricane doesn't get in the way, two astronauts who made their first commercial orbit trip will return home on Sunday.
Two astronauts, Robert L. Behnken and Douglas G. Hurley, traveled to the International Space Station in May aboard a Crew Dragon capsule built and directed by SpaceX, the private rocket company started by Elon Musk.
Crew Dragon is scheduled to disengage from the space station around 7:34 pm. Eastern time on Saturday and dive into the Gulf of Mexico, near Pensacola, Florida, at 2:41 pm. on Sunday, NASA administrator Jim Bridenstine announced on Twitter.
A safe return would open up more trips to and from orbit for future crews of astronauts and possibly space tourists on board the spacecraft.
Hurricane Isaias is expected to sweep Florida's Atlantic coast over the weekend. NASA and SpaceX have seven dive sites in the Gulf of Mexico and the Atlantic, but Isaias' runway discarded the three in the Atlantic.
The match may still be postponed to Sunday night with a drop on Monday afternoon. NASA and SpaceX will make a final decision around 5 pm. proceed with the disengagement.
"We are confident that teams on the ground are, of course, watching much more closely than we are," Behnken said during a news conference on Friday, "and we will not leave the space station without a good landing. ahead, good spawning climate ahead of us. "
Why does Hurricane Isaias affect departure?
The storm complicates when and where the splash may occur. At the crash site, winds must be less than 10 miles an hour for the capsule to land safely. There are additional restrictions on waves, rain and lightning. In addition, helicopters participating in capsule recovery must be able to fly and land safely.
The first landing opportunity will target only the main site, Pensacola. If the weather is not consistent with the rules, the capsule and astronauts will remain in orbit for another day or two, and managers will consider the backup location, which is Panama City.
What will happen after they leave the station?
After undocking on Saturday night, the probe will perform a series of maneuvers, first starting the engines several times to move away from the space station and, a few hours later, to align the probe with the drop zone.
For most of the trip, Behnken and Hurley will be asleep. Their booking schedule 10 hours with eyes closed.
Any return trip that exceeds six hours must be long enough for the crew to get some sleep between undocking and diving, NASA spokesman Daniel Huot said in an email.
Otherwise, due to the extensive process that leads to disengagement, the team would end up working more than 20 hours straight, "which is not safe for dynamic operations like splashing and water recovery," said Huot.
Just before a final burn that will send Crew Dragon out of orbit on Sunday afternoon, it will discard the bottom of the spacecraft, known as the trunk, which will be burned in the atmosphere.
Upon re-entry, Crew Dragon will travel at approximately 27,500 miles per hour. Two small parachutes will be launched at an altitude of 18,000 feet when the probe has already been reduced by the Earth's atmosphere to about 600 miles per hour. The four main parachutes are deployed at an altitude of about 6,000 feet.
After the capsule splashes into the water, it is expected to take 45 to 60 minutes to remove them.
Why is the return trip an important part of Crew Dragon's first flight?
After launch, re-entry into Earth's atmosphere is the second most dangerous phase of space flight. The friction of the rapidly passing air heats the bottom of the capsule to about 3,500 degrees Fahrenheit. A test flight of the Crew Dragon last year crashed successfully, to let engineers know that the system works.
A successful completion of the trip opens the door to more people flying into space. Some companies have already announced plans to use Crew Dragons to elevate tourists rich in orbit.
In the past, NASA astronauts launched spacecraft like the Saturn 5 lunar rocket and the space shuttles that NASA itself operated. Following the retirement of space shuttles in 2011, NASA had to rely on Russia, buying seats in Soyuz capsules for travel to and from orbit.
Under the Obama administration, NASA hired two companies, SpaceX and Boeing, to build spacecraft to take astronauts to the space station. NASA has financed much of the work to develop the spacecraft, but will now buy a ride at fixed prices. For SpaceX, Behnken and Hurley's journey – the first launch of astronauts from American soil since the last space shuttle flight – was the last major demonstration needed before NASA officially certified that Crew Dragon was ready to start regular flights.