SpaceX Crew Dragon offers emergency evacuation option for ISS astronauts

Leaky Soyuz spurs worries for ISS emergency evacuation, SpaceX offers solution.

NASA announced that in case of an emergency, a Crew Dragon vehicle by SpaceX docked at the ISS can be used to bring extra crew members back to Earth. A coolant leak in a Soyuz spacecraft at the ISS prompted international space agencies to devise a plan for safe transport in the event of a future emergency. The plan involves launching a replacement Soyuz in February.

However, there were concerns about what would happen if an evacuation was needed before the replacement arrives. Typically, crew members would leave in the vehicles they traveled in, but the leak raises doubts about the Soyuz's safety for return.

The Soyuz spacecraft could overheat during re-entry if it lacks coolant, so the leaking Soyuz will return to Earth without crew, and its intended crew will use a replacement Soyuz. In an emergency evacuation, NASA astronaut Frank Rubio will travel in the SpaceX Crew Dragon with the four Crew-5 members, and Russian cosmonauts Sergey Prokopyev and Dmitri Petelin will travel in the leaking Soyuz to reduce heat load. Only in emergency situations. NASA and SpaceX verified the safety of using the Crew Dragon for 5 crew members instead of 4, by checking airflow, oxygen, and landing safety.

NASA and SpaceX are exploring options to increase the crew capacity of the Crew Dragon spacecraft. Currently, it has four seats on the upper deck and three cargo pallets on the lower deck, but the cargo area can be converted to accommodate two more crew members if needed. The Crew Dragon was initially designed to carry seven people, but three seats were later converted to cargo storage. According to SpaceX, the vehicle has enough life support to safely carry an additional crew member. The Crew Dragon is also equipped to handle potential impacts from meteoroids while docked at the ISS.

Vehicle safety is ensured through weekly checkups and monthly inspections of docked Crew Dragons on the ISS. The station's robotic arm captures photos/videos of the craft before undocking. Although unlikely to be necessary, officials are prepared for any scenario with a backup plan while waiting for the replacement Soyuz. "We plan for the best, but prepare for the worst," says Kathryn Lueders, Space Operations Mission Directorate Associate Administrator.