SpaceX/NASA

SpaceX's 'Endeavour' Spaceship To Make History Today By Undocking From ISS

At the end of their historic mission, the two astronauts aboard the SpaceX 'Endeavour' will be returning to Earth.

Today, Bob Behnken and Doug Hurley are coming home.

NASA

On the evening of Saturday, August 1, the NASA astronauts left the Internation Space Station and began their day-long journey home.

Aboard the SpaceX 'Endeavour', Behnken and Hurley were the first people to ever be put aboard a SpaceX ship in a mission called Demo-2, and their departure makes SpaceX the first company in NASA's Commercial Crew Program to successfully visit the ISS.

Their descent is a risky one, and has already faced problems when it comes to their landing zone.

The Endeavour has around six potential landing spots, with some having been eliminated as an option due to Hurricane Isaias. Their current plan is to land in a site off the coast of Pensacola, Florida, but if the weather becomes too bad they'll try to land in Panama City instead, about 100 miles east.

Elon Musk, founder of SpaceX, said back ahead of the mission's launch that, "The part that I would worry most about would be reentry."

NASA

The spaceship capsule has an asymmetrical design built to accommodate the emergency launch-escape system thruster pods. These pods cause a bit of imbalance, which though unlikely, could cause a problem.

"We've looked at this six ways to Sunday, so it's not that I think this will fail. It's just that I worry a bit that it is asymmetric on the backshell," Musk said, explaining that if the ship rotates too much there was a chance the ship could overheat or lose control.

But the plan is in place, and their descent is beginning.

NASA

In what is a multi-stage landing process, Endeavour will automatically deploy a set of parachutes at 18,000 feet above the water that will slow them to around 120 mph. Again at 6500 feet above the water, another set of parachutes will deploy and slow them even further until they hit the water at 15 mph.

Alongside this mission, SpaceX and NASA are testing for future big plans.

NASA

This isn't just a mission to put people in space, it's a test to see how safe the ship is in regards to transporting people. SpaceX has looked into a future where they can fly private citizens with Crew Dragon. They'll be reviewing the data from the flight for the next six weeks in order to gain NASA's human-rated certification.

A follow-up mission has already been announced where astronaut Megan McArthur, Behnken's wife, will take the same ship into orbit and stay there for six months.

The descent is scheduled for today, August 2, at 2:48 p.m. ET.

NASA

"It was an honor and privilege to be part of Expedition 63," Hurley said in a tweet as he and Behnken left the ISS. "Now it's time to finish our DM-2 test flight in order to pave the way for future Dragon crews. Go Endeavour!"

NASA Television will be broadcasting the event live.

h/t: Business Insider