NASA astronauts aboard SpaceX’s Crew Dragon capsule splash down in the Gulf of Mexico

SpaceX landing crews delayed opening the hatch of the Crew Dragon Endeavour capsule aboard the recovery ship Go Navigator because of high levels of harmful fumes.

Mission controllers detected higher-than-appropriate amounts of “hypergolic fumes,” or fumes that could explode when coming in contact with one another. Technicians aboard the Go Navigator spent several minutes aerating the service components of the Endeavour to disperse the fumes, which never entered the cabin of the spacecraft. Tests found no toxic fumes inside the capsule.

It’s called Demo-2 for a reason. Demo is short for demonstration, meaning SpaceX’s mission to fly a pair of NASA astronauts to and from the International Space Station is one big test, a way to prove the company is capable to pulling off the feat safely.

The launch and docking two months ago was picture perfect, NASA and SpaceX said. So did the return and splashdown. That means the space agency is likely to certify SpaceX’s vehicles and allow them to begin flying regular operational missions.

The first one, called Crew-1, could happen as soon as late September. NASA has already picked the crew, a quartet of astronauts from different backgrounds.

NASA astronauts Doug Hurley and Bob Behnken reported a successful splashdown in the Gulf of Mexico off the coast of Pensacola, Fla., completing their return mission to Earth from the International Space Station.

Moments after the SpaceX Dragon Endeavour capsule hit the water, mission controllers radioed to the crew congratulating them on their return journey.

“On behalf of the SpaceX and NASA teams, welcome home and thanks for flying SpaceX,” mission control said.

“It’s truly our honor and privilege,” Hurley responded. “On behalf of the Dragon Endeavour, congrats to NASA and SpaceX.” He later radioed back, “All is well.”

Astronauts Bob Behnken and Doug Hurley are back on Earth, but still a ways from home. SpaceX landing crews will launch two speed boats from the recovery mother ship Go Navigator, stationed three miles away from the projected landing site, to verify that the Endeavour spacecraft is safe and prepared for recovery.

The first boat will check to see if the Dragon capsule is leaking any fluids, propellant or vapors. The second boat will retrieve Endeavour’s four parachutes, which the capsule ejects upon splashdown.

The SpaceX Dragon Endeavour capsule carrying NASA astronauts Doug Hurley and Bob Behnken has splashed down in the Gulf of Mexico off the coast of Pensacola, Fla., completing an 18-hour flight to Earth from the International Space Station.

The landing marks the end of the first mission for a NASA crew aboard a private-sector spacecraft. SpaceX, owned by billionaire entrepreneur Elon Musk, beat out industry titan Boeing to send the first manned mission to space as part of NASA’s commercial crew program. Hurley and Behnken lifted off from Kennedy Space Center in Cape Canaveral, Fla., on May 30, and spent 62 days aboard the ISS while NASA and SpaceX officials evaluated the Endeavour’s performance and flightworthiness.

The Dragon capsule has deployed its two drogue parachutes to slow its velocity as it plummets back to Earth on a return mission from the International Space Station. The chutes deploy when Dragon reaches an altitude of 18,000 feet and is traveling at 350 miles per hour.

SpaceX flight engineers have regained communication with astronauts Bob Behnken and Doug Hurley inside the Dragon capsule. Flight crews lost signal with Dragon for about six minutes as the capsule was engulfed in a blazing ball of heat while it reentered Earth’s atmosphere.

SpaceX flight engineers have lost contact with astronauts Bob Behnken and Doug Hurley inside the Dragon capsule as it continues its return mission from the International Space Station. This temporary communication blackout was expected — engineers call the event “LOS,” or “loss of signal” — and is caused by the intense heat that surrounds the capsule as it reenters Earth’s atmosphere. The communication disruption is expected to last six minutes, according to flight plans.

Conditions at the splashdown site are excellent.