Four astronauts splashed down safely in the Gulf of Mexico Monday night, ending an eventful six-month stay on the International Space Station, which was forced off its trajectory twice during the astronauts’ expedition because of errant thruster firings.

Under a quartet of parachutes, the SpaceX Dragon spacecraft splashed down softly in the Gulf of Mexico off Pensacola, Fla., at 10:33 p.m. after undocking from the orbiting laboratory more than eight hours earlier.

On board the autonomous spacecraft were two NASA astronauts, commander Shane Kimbrough and pilot Megan McArthur. They were accompanied by astronauts Thomas Pesquet of France and Akihiko Hoshide of Japan.

The successful splashdown appeared to go flawlessly, except that one of the four main parachutes inflated slower than the others.

Speaking after the splashdown, Kathy Lueders, the head of NASA’s Space Operations Mission Directorate, joked that “I’m always amazed that I can hold my breath for those last 10 minutes of re-entry. That is high drama right there and ... seeing those chutes come out, it’s just an amazing thing.”

She said that “the return looked spotless.” But she conceded that, “I know folks will be wondering about the that one lagging main parachute. And the team will be going off and looking at how the loading was on the chutes and understanding that behavior. It is behavior we’ve seen multiple times on other tests, and usually happens when the lines kind of bunch up together until the aero forces kind of open up and spread the chutes.”

The return comes at a busy time for human spaceflight. On Wednesday, SpaceX is scheduled to launch another quartet of astronauts to the space station — a mission that had been scheduled to lift off last week but was delayed because of weather and an astronaut’s illness. NASA did not say which astronaut got sick or what the illness was, other than it was not covid.

The Crew-2 astronauts who returned Monday had two dramatic moments onboard the station when it was forced out of position because of errant thruster firings, prompting the NASA crew to evacuate the station at least once and board their Dragon spacecraft in case they needed to come home.

“The ground teams really, really worked hard to make sure we were in the safest posture possible,” NASA astronaut Shane Kimbrough told reporters last week. “We were actually in the Dragon capsule in case something really bad did happen. We were ready to go and undock if that was necessary. Of course, it wasn’t, thankfully.”

He didn’t say when they evacuated the station, and a NASA public affairs officer could not provide an answer or confirm that the astronauts boarded Dragon. In July, the thrusters of a newly installed Russian module fired unexpectedly, sending the station on a wild ride. It spun one and a half times, and ended up upside down, before crews could right the football field-sized ship.

NASA said the crew was never in danger, but afterward Zebulon Scoville, a NASA flight director, wrote on Twitter he had never “had to declare a space craft emergency until now” and that he had never “been so happy to see all solar arrays + radiators still attached.”

Then, last month, the station was again forced out of position during the test firing of the thrusters of a Russia spacecraft that was attached to the station. The test was supposed to come to an end, but the thruster kept firing unexpectedly, NASA officials said.

Ground crews regained control of the station in less than an hour, NASA has said.

The astronauts were on board for another dramatic event — the filming of a scene for a Russian movie. Russian actress Yulia Peresild and producer-director Klim Shipenko visited to shoot a scene for a film called “The Challenge” about a doctor sent to save an astronaut’s life.

Before heading home, the Dragon spacecraft, dubbed Endeavour, flew around the space station so that the astronauts could photograph the exterior. The fly-around was not done in response to the errant thruster firings, NASA said, but rather as a general inspection of the more-than-20-year-old station.

During their time on the station, the astronauts performed more than 300 experiments and participated in four spacewalks. As Thomas Pesquet, a French astronaut put it: “The mission has certainly been very, very intense.”

The ride home was intense as well. Plunging through the atmosphere, the Dragon capsule endured temperatures of more than 3,500 degrees Fahrenheit, engulfing the spacecraft in flames. Astronauts aboard the capsule also were asked not to use the spacecraft’s toilet during the eight-hour return because of a malfunction that SpaceX had discovered after another recent flight.

Still, as it neared the Gulf of Mexico, the capsule successfully deployed its parachutes and touched down safely, completing another mission for SpaceX, landing precisely on time.

SpaceX and NASA will now turn their attention to Wednesday’s launch, scheduled for 9:03 p.m., from the Kennedy Space Center in Florida. That flight will carry NASA astronauts Raja Chari, Tom Marshurn and Kayla Barron as well as Matthias Maurer of Germany. They’ll join NASA astronaut Mark Vande Hei and two Russian cosmonauts, bringing the space station’s population back to seven.

Here’s what you need to know

  • The returning astronauts spent 199 days in space.
  • During their time aboard the space station, the Crew-2 astronauts performed more than 300 experiments.
  • They also experienced two harrowing unplanned events when Russian rocket engines fired unexpectedly, sending the International Space Station off its trajectory. During one of those, the Crew-2 astronauts reentered the Dragon capsule in case they had to abandon the station, Kimbrough said last week.