SpaceX Crew-6 Set to Return to Earth Following a Six-Month Stay at the ISS

After spending more than six months in space, the four crew members of the SpaceX Crew-6 mission are preparing to splashdown in the waters near Florida. The mission, which launched on March 2 and docked with the International Space Station (ISS) the following day, undocked on September 3 and is scheduled to return to Earth on September 4.

The crew members returning to Earth include Commander Stephen Bowen and Pilot Warren “Woody” Hoburg from NASA, Russian cosmonaut Andre Fedyaev, and Sultan AlNeyadi from the United Arab Emirates. AlNeyadi is the first long-duration crew member from the UAE and only the second Emirati to fly in space.

Crew Dragon Endeavour initially docked to the zenith port of the Harmony node of the ISS back in March but was moved to the forward docking port of the same module in May to allow for an incoming Cargo Dragon capsule to be closer to the station’s robotic arm. The capsule will autonomously back away from the ISS using its onboard computers.

To maneuver outside of the “Keep-Out Sphere,” Crew Dragon Endeavour will use its built-in Draco thrusters in two separate burns known as burn zero and burn one. The Keep-Out Sphere extends 200 meters around the ISS and denotes when NASA and other ISS partner nations are involved with the mission. Once outside of this sphere, control of the mission switches over to SpaceX.

Approximately one hour after undocking, a longer burn known as burn two will be performed to place the capsule in a lower orbit below and away from the ISS. SpaceX and NASA have seven potential splashdown sites, with four located in the Gulf of Mexico and three in the Atlantic Ocean. The primary and secondary landing sites are typically selected two weeks in advance.

Recovery vessels are prepared to retrieve the crew and their capsule from the Atlantic Ocean. The primary recovery vessel, named Megan after astronaut Megan McArthur, was relocated to Port Everglades to avoid Hurricane Idalia before moving to its splashdown location. The second recovery vessel, Shannon, named after astronaut Shannon Walker, was docked in Tampa along the west coast of Florida.

Both recovery ships are equipped with a helipad for transporting astronauts to shore, a medical facility for observing their conditions, and radar to track the spacecraft. The back of the boats contains a lift that attaches to special points on the capsule. Once connected, the capsule is lifted onto a stand and retracted underneath a covering on the ship.

The weather requirements for Crew Dragon splashdowns include no lightning within 10 miles, waves with no greater than a seven-degree slope, wind speed no greater than 12 miles per hour, less than a 25 percent chance of rain, and at least one-half mile visibility in the daytime or one mile at night.

Approximately one hour before splashdown, Endeavour will jettison its unpressurized segment known as the trunk, revealing Dragon’s tiled heat shield. This will be followed by a deorbit burn to slow down the spacecraft enough to re-enter Earth’s atmosphere. The forward thrusters around the docking ring are used for this burn.

As plasma builds around the capsule during re-entry, mission controllers will temporarily lose contact with the crew. Once at a certain altitude and velocity, Endeavour will deploy its drogue parachutes, slowing down to around 350 miles per hour. The parachutes partially deploy before fully inflating in a controlled manner.

Shortly after full drogue inflation, the drogue parachutes are cut and the main parachutes are deployed. The four main parachutes also reef to ease the loads on the capsule and crew. They slow Dragon down to around 15 miles per hour for splashdown.

During their time on the ISS, the Crew-6 members contributed to various science experiments and technology demonstrations. This included human health experiments such as bioprinting knee tissue in microgravity. They also helped install more of the Station’s new ISS Roll-Out Solar Arrays (iROSA) during a spacewalk, which will increase power for operations and scientific investigations on the ISS.

The crew also conducted Earth science experiments, photographing and documenting the planet. They also connected with and spoke to students from space. This mission marks SpaceX’s sixth operational crew mission to the ISS under NASA’s Commercial Crew Program.

As the Crew-6 mission comes to a close, the successful return of the crew and their capsule will mark another milestone in the ongoing collaboration between SpaceX and NASA in advancing human space exploration and scientific research.