This afternoon, NASA astronauts Bob Behnken and Doug Hurley are scheduled to begin their journey back to Earth inside SpaceX’s new Crew Dragon, ending their historic flight to the International Space Station. If all goes according to plan, the two will be splashing in the Crew Dragon off the west coast of Florida on Sunday afternoon.
Getting back to Earth from orbit is no easy task, and the two astronauts have a long journey ahead of them before returning to solid ground. Once Behnken and Hurley detach from the space station, they will spend the next 18 hours in orbit, slowly receding from the ISS, before plunging into Earth’s atmosphere. It begins a heart-wrenching journey to the surface, as the Crew Dragon endures extreme temperatures of up to 3,500 degrees Fahrenheit and slows down from 17,500 miles per hour.
Things begin this afternoon, when Behnken and Hurley climb inside the Crew Dragon and close the hatch around 5:45 p.m. ET. They will remain indoors until the scheduled undocking time at 7:34 p.m. ET. The hooks that hold the Crew Dragon in place at the Station will retract, freeing the capsule into space. Right after that, the Crew Dragon’s thrusters will do two quick burns in order to separate themselves further from the ISS.
A few hours after undocking, the Crew Dragon will burn another engine to put the vehicle on the way to its intended landing site. Right now, NASA and SpaceX are aiming for a splashdown off Pensacola, on the begging edge of Florida in the Gulf of Mexico. The location is one of seven potential sites in Florida where the Crew Dragon could land. NASA and SpaceX would prefer the Crew Dragon to land on the east side of Florida, near the Kennedy Space Center in Cape Canaveral, Florida. However, Tropical Storm Isaias is expected to crush eastern Florida this weekend, forcing Behnken and Hurley to head further west. If Pensacola doesn’t work, the Crew Dragon will head to a backup site outside of Panama City. If either location works, it will be the first time a spacecraft has landed in the Gulf of Mexico.
After this final burn, it takes a long time for things to pick up. Behnken and Hurley will try to sleep the night before their planned descent into the atmosphere on Sunday afternoon. At approximately 1:44 p.m. ET on Sunday, SpaceX will drop a large chunk of the Crew Dragon before landing: the capsule chest. It is a cylindrical piece of equipment attached to the aft end of the capsule, providing support during launch and providing additional space to transport cargo. It also houses all of the solar panels that generate power for the Crew Dragon during flight. But when it comes time to land, SpaceX no longer needs the safe, so it splits up and falls into Earth’s atmosphere, where it burns.
Sunday at 1:49 p.m. ET, the last descent begins. The Crew Dragon will burn its thrusters again, pulling the capsule out of orbit and putting it on the right track for Earth. This starts a series of very rapid events. The Crew Dragon will begin to heat up as it falls into the atmosphere, while the capsule’s outer heat shield should protect the vehicle and crew inside. The amount of heated plasma that builds up around the capsule is so intense that it actually triggers a communication failure that will last up to six minutes.
The atmosphere helps cushion the fall of the Crew Dragon, slowing it down tremendously. But the capsule needs a little more help to descend safely. At an altitude of approximately 18,000 feet, two drug parachutes will deploy from the capsule as it moves at approximately 350 miles per hour. These small drops slow the capsule down to about 119 miles per hour before the major parachutes deploy. When the Crew Dragon reaches an altitude of 6,000 feet, four large red and white parachutes will deploy to continue to brake the vehicle, allowing it to land gently in the ocean around 2:41 p.m. ET.
As soon as the capsule is in the water, two SpaceX boats carrying dozens of people will meet up with the Crew Dragon. They’ll hoist the capsule out of the ocean, retrieve the parachutes, then bring Behnken and Hurley out into the fresh air. The astronauts will then be airlifted to shore, via a helipad on one of the salvage ships. The helicopter will take them on a plane that will bring them back to Houston.
NASA coverage of the landing will begin at 5:15 p.m. ET, just before Behnken and Hurley enter the Crew Dragon. The agency will provide continuous live coverage throughout the screening, showing scenes from NASA and SpaceX mission control centers. That way, viewers can follow every step of Behnken and Hurley’s return journey.