NASA astronauts splash down off coast of Florida to end historic SpaceX mission

A SpaceX Crew Dragon capsule in orbit retracted its claw from an attached trunk Sunday, releasing the support structure and exposing a massive heat shield designed to protect NASA astronauts Bob Behnken and Doug Hurley from the treacherous process of Earth entry.

The spacecraft that departed the International Space Station only 19 hours earlier then performed a critical deorbit burn, placing the duo on an irreversible trajectory toward the Gulf of Mexico. As expected, plasmas that quickly formed around the capsule during re-entry caused a communications blackout as the heat shield kept thousands of degrees at bay and the interior a toasty 85 degrees.

After several callouts to Crew Dragon with no response, Hurley's signal finally made it through: "Endeavour has you loud and clear."

Named Endeavour for SpaceX's second demonstration – but first crewed – mission to the ISS, the spacecraft successfully deployed its parachutes, then set the astronauts down on calm, "glass-like" waters about 40 miles off the coast of Pensacola. As expected, the splashdown was observed at 2:48 p.m. Eastern time.

"On behalf of the SpaceX and NASA teams, welcome back to planet Earth," a mission manager at SpaceX's headquarters in California said. "Thanks for flying SpaceX."

"It truly was our honor and privilege to fly this flight of the Crew Dragon and Endeavour," mission commander and former space shuttle astronaut Hurley said while waiting for recovery teams.

After plucking the 27,000-pound capsule out of the water, teams on SpaceX's Go Navigator ship asked Behnken and Hurley to remain in the capsule for a bit longer than expected as the spacecraft vented remnants of dangerous engine propellants. The duo were cleared to start leaving the capsule a little over an hour after splashdown.

After the egress process, SpaceX and NASA medical teams performed quick checkups before a helicopter landed on the ship for transport back to a Pensacola airport. A NASA jet was scheduled to take them to Johnson Space Center in Houston, Texas, Sunday evening.

Their wives, Megan McArthur and Karen Nyberg, also both astronauts, and children were expected to greet them at JSC. Hurley is a retired Marine Corps colonel and Behnken is an active-duty Air Force colonel.

Sunday's operations brought a safe end to a wildly popular and successful Demo-2, which was SpaceX's last demonstration mission before NASA certifies the spacecraft for full-time human spaceflight. If post-splashdown checkouts and data reviews look good, the agency is scheduled to fly eight astronauts on two separate flights later this year and early next year.

Behnken and Hurley's liftoff from Kennedy Space Center on May 30 marked the first time in nearly a decade that NASA astronauts launched from U.S. soil. After they arrived on station, the duo worked on their spacecraft, helped the ISS crew with science experiments, and hosted countless interviews from 250 miles above Earth.

In total, the "space dads," as they're affectionately known, traveled millions of miles during their 1,024 orbits of Earth. Their Sunday splashdown also marked the first time in 45 years – since the Apollo-Soyuz program – that NASA astronauts splashed down in a American-made capsule.

The only wrinkle noted during post-splashdown operations was the unexpected arrival of several privately owned boats, which encircled Crew Dragon to try and get an up-close view. The presence of unauthorized boats can not only be dangerous for returning astronauts, but for the boaters themselves as spacecraft vent toxic propellants used in space.

NASA's efforts to restore American human spaceflight are collectively known as the multibillion-dollar Commercial Crew Program, which also selected Boeing's Starliner capsule for future flights to the ISS. That spacecraft is expected to fly on an uncrewed demonstration mission no earlier than October.

"Anybody who's touched Endeavour, you should take a moment to just cherish this day, especially given all the things that have happened this year," Hurley said as Behnken, also a former shuttle astronaut, was removed from the capsule. "We certainly can't thank you enough and our families can't think you enough. We're just proud to be a small part of this effort to get people to and from the space station."

Contact Emre Kelly at aekelly@floridatoday.com or 321-242-3715. Follow him on Twitter, Facebook and Instagram at @EmreKelly. Support his space journalism by subscribing at floridatoday.com/specialoffer/.