LOS ANGELES • Four astronauts have returned safely from a record six-month Nasa science mission aboard the International Space Station, splashing down with their SpaceX Crew Dragon capsule in the Gulf of Mexico at the end of a day-long flight home.
The Dragon vehicle, dubbed Endeavour, parachuted into the sea off the Florida coast as planned, just after 10.30pm on Monday, following a re-entry descent through Earth's atmosphere carried live by a US National Aeronautics and Space Administration (Nasa) webcast.
Real-time infrared thermal video imaging captured a glimpse of the capsule streaking like a meteor through the night sky over the Gulf minutes before splashdown.
Applause was heard from the flight control centre as the four main parachutes inflated above the capsule, seen drifting down towards the Gulf surface and slowing to about 24kmh before dropping gently into the calm sea.
"Endeavour, on behalf of SpaceX, welcome home to planet Earth," a voice from the SpaceX flight control centre in suburban Los Angeles was heard telling the crew as a safe splashdown was confirmed.
"It's great to be back," one of the astronauts radioed in reply.
The return capped 199 full days in orbit, the longest ever for an entire US-launched crew, according to Ms Kathy Lueders, associate Nasa chief for space operations.
Within an hour of splashdown, the capsule was hoisted onto the deck of a recovery ship, and the four astronauts were seen emerging one by one from Endeavour's hatch.
Two Nasa astronauts on the flight - pilot Megan McArthur, 50, and mission commander Shane Kimbrough, 54 - were the first two out of the vehicle. They were followed by Japanese crew mate Akihiko Hoshide, 52, and fellow mission specialist Thomas Pesquet, 43, a French engineer from the European Space Agency.
Each flashed smiles and a victory sign as they were helped onto waiting gurneys, unable to immediately bear their own weight after months in microgravity. They were to undergo brief medical checkups, then flown to shore via helicopter.
Operating autonomously, the spacecraft began its eight-hour return voyage earlier in the day with a 90-minute fly-around of the space station as the crew snapped a series of survey photographs of the orbiting outpost, circling the globe some 400km above.
The Crew Dragon then proceeded through a series of manoeuvres over the course of the day to bring it closer to Earth ahead of its final night-time descent.
Propelled by one last ignition of its forward rocket thrusters for a "de-orbit burn", the capsule re-entered the atmosphere at about 27,359kmh for a free fall towards the ocean below, during which crew communications were lost for several minutes. Intense friction generated as the capsule plunged through the atmosphere slowed its descent while sending temperatures surrounding the vehicle soaring to 1,927 deg C.
The astronauts were launched to orbit atop a SpaceX Falcon 9 rocket lifting off from Florida's Kennedy Space Centre on April 23.
The returning team was designated "Crew 2" because it marks the second "operational" crew that Nasa has launched aboard a SpaceX capsule since resuming human space flights from American soil last year, after a nine-year hiatus from the end of the US space shuttle programme in 2011.
The replacement team, "Crew 3," was originally slated to fly to the space station at the end of last month, but that launch has been delayed by weather problems and a medical issue involving a crew member.