A SpaceX Crew Dragon vehicle currently docked to the International Space Station (ISS) can be used to transport additional crew members back to Earth in an emergency, NASA announced.
After a coolant leak in a Russian Soyuz spacecraft docked with the ISS in December, international space agencies, including NASA and Roscosmos, worked together to devise a plan to safely transport crew members home. The plan they came up with was to use a replacement Soyuz craft to be launched in February.
However, observers were concerned about what would happen in the event of an emergency involving evacuation of the ISS between now and the arrival of the replacement Soyuz. Usually, crew members evacuated in the vehicles they traveled to the station in, but with the Soyuz leak, it’s not certain the vehicle would be safe for a return trip.
Leaky Soyuz spacecraft raises questions about ISS crew evacuation in case of emergency
The problem is that without its coolant, the Soyuz could overheat as it travels back through Earth’s atmosphere. Therefore, it is planned that the drained Soyuz will return to Earth without a crew and that the crew members who were scheduled to travel will use the replacement Soyuz instead.
But in the event of an emergency evacuation, the plan is for NASA astronaut Frank Rubio to travel in the SpaceX Crew Dragon along with the four Crew-5 members, and for Russian cosmonauts Sergey Prokopyev and Dmitri Petelin to travel in the Soyuz who experienced the leak. . .
“What we wanted to do was reduce the heat load in the Soyuz, so by removing Rubio from the Soyuz, you remove a third of the human heat load,” explains Joel Montalbano, International Space Station program manager at NASA. in a press conference on Wednesday. He emphasized that this would only be necessary in an emergency situation.
As for the NASA astronaut who traveled to the space station in the Soyuz, NASA worked with SpaceX to verify that the existing Crew Dragon vehicle would be safe to carry five crew members instead of four, including airflow control, oxygen supply and whether landing would be safe.
The problem is that without its coolant, the Soyuz could overheat as it travels back through Earth’s atmosphere
“We found that this payload space could be about the right size to fit a seat cover and a crew member in this area,” said Steve Stich, manager, commercial crew program, NASA Johnson Space Center. “We could even accommodate two more crew members in this cargo pallet area if needed.”
Currently, the Crew Dragon layout has an upper deck with four seats and a lower deck with three cargo pallets. But if necessary, four crew members can sit on the upper deck and one or more of the lower deck spaces can be converted from cargo space to crew seating.
“In the early days of the Crew Dragon interior design, we designed the interior to seat up to seven people, and that was later modified to convert three of those seats into areas that could be used as cargo storage, said Sarah Walker, Director of Dragon Mission Management at SpaceX.
SpaceX checked the numbers and found it safe for the vehicle to carry an additional crew member. “Dragon has plenty of margin, even with the extra crew member, in terms of onboard life support,” Walker said.
As for whether there could be future leaks to vehicles attached to the ISS, there remains the threat of meteoroids, which can travel at very high speeds and potentially hit and damage craft docked there. That is believed to be the cause of the damage to the Soyuz’s radiator. But NASA says the SpaceX Crew Dragon is equipped to handle such shocks.
“Dragon has plenty of margin, even with the extra crew member, in terms of onboard life support.”
“We designed that vehicle so that it already has some degree of protection for the environment, around critical systems like the propellant tanks and other areas,” said Stich. “We went into the design knowing that this was one of our risk areas.”
To ensure that vehicles can travel safely, Crew Dragons docked at the ISS are inspected during weekly checkouts and more extensive monthly surveys. The station’s robotic arm is also used to take pictures and videos of vessels before they are undocked.
While it is unlikely that this contingency plan will be necessary, officials stressed that they wanted to be prepared for any scenario that could arise pending the replacement Soyuz’s arrival at the space station. “We always plan for the best — and sometimes the worst,” said Kathryn Lueders, associate administrator, Space Operations Mission Directorate.