SpaceX showed it can safely ferry astronauts to and from space. In September, it'll launch 4 more — here's who's next.

• The success of SpaceX's Demo-2 mission tees the company and NASA up for their next crewed launch.
• That mission, called Crew-1, will ferry four astronauts to the space station and back: Victor Glover, Shannon Walker, Mike Hopkins, and Soichi Noguchi.
• The team is expected to launch in late September.

When NASA astronauts Bob Behnken and Doug Hurley landed in the Gulf of Mexico after a fiery fall through Earth's atmosphere, people around the world breathed sighs of relief — including a group of four fellow astronauts in Houston.

The success of the mission, a high-stakes test of SpaceX's Crew Dragon spaceship, showed that NASA could successfully partner with the company to fly astronauts to and from the International Space Station.

The four astronauts who'd been watching in Houston are the crew of SpaceX's Crew-1 mission, the next round trip to the ISS. NASA astronauts Shannon Walker, Mike Hopkins, and Victor Glover, as well as JAXA (Japan Aerospace Exploration Agency) astronaut Soichi Noguchi, are expected to launch in September.

"It was all a very emotional event for all of us — to be able to watch our colleagues, our friends, come home safely," Walker said in a press conference following the landing. He added, "we're very excited that it went as smoothly as it did, because that really points to the success of how our mission will be when we get a chance to launch."

NASA and SpaceX plan to launch at least six missions to the ISS (not including this recent demo) using SpaceX rockets and the Crew Dragon capsule. The partnership frees NASA from its reliance on Russian Soyuz spacecraft, which have recently cost up to $90 million per seat. NASA hasn't been able to launch astronauts in American systems since 2011, when it ended the space shuttle program. A seat on a SpaceX shuttle is projected to cost $55 million (not counting the funding NASA gave the company to develop the Crew Dragon in the first place).

The success of the recent mission kicked off "a new era in spaceflight," SpaceX founder Elon Musk said on Sunday.

Meet the Crew-1 astronauts

The Crew-1 astronauts plan to stay on the ISS for the standard six months, during which they'll conduct space walks, d0 science experiments, and work on regular station maintenance. Like other crews, they'll bring a diverse array of expertise and backgrounds to their work.

Hopkins, the mission commander, grew up on a farm in Missouri and was a special assistant to the Vice Chairman of the Joint Chiefs of Staff before becoming an astronaut in 2009. A colonel in the Air Force, he served as a flight test engineer. He spent 166 days on the space station in 2013.

Walker, a mission specialist, was born in Houston, Texas, and was hired by NASA in 1995. She worked on robotics hardware and other initiatives before being selected as an astronaut in 2004. She spent 161 days on the ISS in 2010.

Glover, the crew's pilot, was selected as part of NASA's 21st astronaut class in 2013, while serving as a Legislative Fellow in the US Senate. He's a former Navy commander, aviator, and test pilot, with over 3,000 hours flying experience — but this will be his first spaceflight.

Noguchi, who will also serve as a mission specialist, is an aeronautical engineer from Japan. A former Boy Scout, he was selected as an astronaut in 1996 and has spent 177 days in space.

If the Crew-1 mission goes as planned, Noguchi will have flown on three different spacecraft: He has also flown on Russia's Soyuz and the US Space Shuttle. A JAXA astronaut, Noguchi the only non-NASA member of Crew-1. Part of the motivation for the NASA-SpaceX partnership was to enable other countries' space agencies to purchase seats as well, further loosening Russia's monopoly on spaceflight.

"We have a great variety or diversity in this crew. And my small contribution to this great team is experience," Noguchi told reporters during a post-splashdown conference on Sunday.

After Crew-1, SpaceX's subsequent Crew-2 mission is scheduled to depart in the spring. That crew is slated to fly the same Crew Dragon capsule that Behnken and Hurley used. Crew-2 will also involve four astronauts: NASA astronauts Megan McArthur and Shane Kimbrough, JAXA astronaut Akihiko Hoshide, and European Space Agency astronaut Thomas Pesquet.

McArthur, who will pilot the ship, is also Behnken's wife.