Astronauts splash down off Los Angeles coast after nearly 8 months in space

Four astronauts returned to Earth Thursday morning, splashing down in the Pacific Ocean off the coast of Los Angeles after spending nearly eight months aboard the International Space Station.

The SpaceX Dragon spacecraft carrying NASA astronauts Jessica Meir and Jack Hathaway, European Space Agency astronaut Sophie Adenot and Russian cosmonaut Andrey Fedyaev splashed down at 8:34 a.m. PDT, according to NASA.

The landing marked the end of the Crew-12 mission, which began in February and included scientific research and four spacewalks aboard the orbiting laboratory.

The crew launched from Cape Canaveral Space Force Station in Florida on Feb. 13 aboard a SpaceX Falcon 9 rocket and arrived at the International Space Station the following day.

Their return journey began Wednesday morning when the Dragon spacecraft, named Freedom, undocked from the station at 5:05 a.m. PDT, beginning an approximately 27-hour trip back to Earth.

By Thursday morning, NASA reported favorable weather conditions at the primary splashdown site in the Pacific Ocean near Los Angeles, allowing recovery teams to proceed with the landing.

The spacecraft began its final descent Thursday morning after completing a roughly 9-and-a-half-minute deorbit burn, according to Space.com.

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Got me to wondering what the astronauts experience during that deorbit burn. I figured some pretty high G loads. Boy, was I wrong!

The de-orbit burn itself produces only about 0.02 g. You would not even feel that. In everyday terms, that is the same as taking 2 minutes and 17 seconds to go from 0 to 60 mph! And this from the guy who makes the Tesla 3-motor hotrods. A Tesla Model 3 "Performance" AWD takes 2.9 seconds 0-60 which is 0.94 g.

Crew Dragon performs that burn with four forward Draco thrusters (400 N each, so 1,600 N total) after the trunk is jettisoned. A typical ISS de-orbit Δv is on the order of 100 m/s. For the 9.5-minute burn cited in Crew-12 coverage (570 seconds), average acceleration is

a = Δv / t ≈ 100 m/s / 570 s ≈ 0.175 m/s² ≈ 0.018 g.

That matches a post-trunk capsule mass of roughly 9 tonnes under 1,600 N of thrust. The burn is deliberately long and gentle so small timing errors do not throw the entry trajectory off; SuperDracos are not used for this maneuver.

The 3–5 g peak the crew feels comes later, from atmospheric drag during re-entry, not from the thrusters.

“Post-trunk capsule mass” means the mass of the Crew Dragon capsule after the trunk has been jettisoned. The "trunk" is the unpressurized cylindrical section attached behind the heat shield. It carries the solar panels and some cargo, and it is discarded before the de-orbit burn so the heat shield is exposed and the vehicle is lighter. Once it is gone, only the pressurized capsule (crew, remaining propellant, and structure) is left. That remaining mass is what the four Draco thrusters decelerate during the burn—roughly 9 tonnes in the estimate above.

The trunk is discarded and burns up in the atmosphere. The trunk has no heat shield and is not designed to survive re-entry, so it follows its own decaying path, heats up, and is destroyed. Only the capsule continues to splashdown under parachutes.

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