The first astronauts to ride a SpaceX capsule into orbit headed toward a retro-style splashdown in the Gulf of Mexico on Sunday afternoon to close out a two-month test flight.

It will mark the first splashdown in 45 years for NASA astronauts and the first return in the gulf. Unlike Florida’s Atlantic coast, already feeling the effects of Tropical Storm Isaias, the waves and wind were calm near Pensacola in the Florida Panhandle.

Test pilots Doug Hurley and Bob Behnken departed the International Space Station on Saturday night, and awoke to a recording of their young children urging them to “rise and shine” and “we can’t wait to see you.”

“Don’t worry, you can sleep in tomorrow,” said Behnken’s 6-year-old son Theo, who was promised a puppy after the flight. “Hurry home so we can go get my dog.”

Their atypical ride home by Elon Musk’s SpaceX company — the first commercially built and operated spacecraft to carry people to and from orbit — was expected to be fast, bumpy and hot, at least on the outside. Splashdown was set for 2:48 p.m. Eastern.

Plans called for the Dragon capsule, named Endeavour by its crew, to go from a screaming orbital speed of 17,500 mph (28,000 kph) to 350 mph (560 kph) during reentry in the atmosphere and finally to 15 mph (24 kph) at splashdown. Peak heating during descent: 3,500 degrees Fahrenheit (1,900 degrees Celsius). Top G forces: four to five times the force of Earth’s gravity.

A SpaceX recovery ship with more than 40 staff, including doctors and nurses, was poised to move in at splashdown, with two smaller, faster boats leading the way. To keep the returning astronauts safe in the pandemic, the recovery crew self-quarantined for two weeks and were tested for the coronavirus.

SpaceX expected it to take a half-hour for the ship to arrive at the capsule and additional time to lift it out of the water onto the deck. A flight surgeon was going to be the first to look into the capsule, once the hatch is pulled open. After medical exams, the astronauts were expected to fly home to Houston.

The last time NASA astronauts returned from space to water was on July 24, 1975, in the Pacific, the scene of most splashdowns, to end a joint U.S.-Soviet mission known as Apollo-Soyuz. The Mercury and Gemini crews in the early to mid 1960s parachuted into the Atlantic, while most of the later Apollo capsules hit the Pacific. The lone Russian “splashdown” was in 1976 on a partially frozen lake amid a blizzard following an aborted mission; the harrowing recovery took hours.

SpaceX made history with this mission, which launched May 30 from Florida. It was the first time a private company launched people into orbit and also the first launch of NASA astronauts from home turf in nearly a decade. Hurley came full circle, serving as pilot of NASA’s last space shuttle flight in 2011 and the commander of this SpaceX flight.

NASA turned to SpaceX and also Boeing to ferry astronauts to and from the space station, following the retirement of the shuttles. Until Hurley and Behnken rocketed into orbit, NASA astronauts relied on Russian rockets.

SpaceX needs six weeks to inspect the capsule before launching the next crew around the end of September. This next mission of four astronauts will spend a full six months aboard the space station. Hurley and Behnken’s capsule will be refurbished for another flight next spring.

Boeing doesn’t expect to launch its first crew until next year. The company encountered significant software problems in the debut of its Starliner capsule, with no one aboard, last year.

By beating Boeing, SpaceX laid claim to a U.S. flag left at the space station by Hurley and the rest of the last shuttle crew. The flag — which also flew on the first shuttle flight — was carefully packed aboard the Dragon for the homecoming.