NASA astronauts on historic SpaceX mission aiming for August 2 return

New York(CNN Business) NASA astronauts Robert Behnken and Douglas Hurley, the first-ever astronauts to travel into orbit aboard a commercially developed spacecraft, are aiming to return to Earth on August 2, the space agency announced Friday.

The exact time and date of their return home will be determined by weather, NASA Administrator Jim Bridenstine said on Twitter.

Millions of people watched as Behnken and Hurley strapped into a SpaceX Crew Dragon capsule on May 30, launching their months-long mission to the International Space Station. It marked the first time in nearly a decade that humans launched to the ISS from US soil, and it was the first crewed mission for SpaceX in its 18-year history.

Behnken and Hurley have spent the past two months aboard the ISS alongside NASA astronaut Christopher Cassidy and Russian cosmonauts Anatoli Ivanishin and Ivan Vagner, who had previously flown to the orbiting laboratory aboard a Russian-built Soyuz spacecraft.

The NASA astronauts have spent their days conducting space walks to upgrade the space station's hardware as well as handling scientific experiments designed for the microgravity environment on board the station. They've also shared images snapped from a viewing module aboard the space station, which has orbited the Earth and hosted astronaut crews from all over the world for two decades.

The United States is one of the space station's primary operators, but the country hasn't had the ability to launch its own astronauts to the ISS since the Space Shuttle program ended in 2011. Since then, NASA's astronauts have had to travel to Russia and train on the country's Soyuz spacecraft on seats that have cost up to $90 million each.

SpaceX worked for a decade to develop its own replacement for the Shuttle under a $2.6 billion fixed-priced contract with NASA. Though largely funded by taxpayers, SpaceX designed and owns its Crew Dragon capsules and the associated Falcon 9 rockets they fly aboard. NASA will serve as SpaceX's customer, purchasing seats for astronauts as needed, and allow the company to sign up its own passengers, including tourists, scientists and even movie stars for future missions.

The journey Behnken and Hurley began in May won't be considered a success until they return safely to Earth. And the voyage home will be just as perilous as the ride to orbit.

Weather permitting, the astronauts will board their Crew Dragon spacecraft on August 1 and spend one day slowly descending toward Earth. The next day, the capsule will slice back through the Earth's thick atmosphere and deploy parachutes to cushion their landing in the Atlantic ocean.

If done successfully, SpaceX's Crew Dragon vehicle could be officially certified for human spaceflight missions. (Behnken and Hurley's trip is considered a test flight.)

NASA's decision to set a target return date is a sign that SpaceX is on track to have a second Crew Dragon ready to fly the first operational crewed mission, dubbed Crew-1, this fall. That mission is slated to take three NASA astronauts — Victor Glover, Michael Hopkins, Shannon Walker — and Soichi Noguchi, an astronaut with Japan's space agency, to the ISS.