SpaceX this weekend will attempt the first U.S. splashdown of returning astronauts in darkness since the Apollo 8 moonshot in 1968.

Elon Musk's company is targeting the predawn hours of Sunday to bring back three NASA astronauts and one from Japan, after dangerously high wind scuttled a pair of earlier attempts.

The astronauts – only the second crew to fly SpaceX – will depart the International Space Station on Saturday night aboard the SpaceX Dragon capsule that carried them up last November. They'll aim for a splashdown 6 1/2 hours later, around 3 a.m. in the Gulf of Mexico off the coast of Panama City, Florida.

SpaceX brought back a station cargo capsule with a splashdown in darkness in January. That adds to NASA's confidence for a nighttime homecoming, said Rob Navias, a spokesman at Johnson Space Center in Houston.

"SpaceX has done numerous dress rehearsals and spent a lot of time with nighttime recoveries," he said.

Navias said the time slot provided the best weather conditions in the coming days.

The departure of NASA's Mike Hopkins, Victor Glover and Shannon Walker and Japan's Soichi Noguchi will leave seven aboard the space station. Their replacements – representing the U.S., Japan and France – arrived last weekend in their own SpaceX capsule for a six-month mission. The three remaining crew members – one American and two Russians – launched in a Russian capsule from Kazakhstan three weeks ago.