NASA says its next spacewalk will be delayed indefinitely until engineers understand more about what caused the June 24 coolant leak.
Tracy Dyson, a NASA astronaut, briefly escaped from her space suit a month ago while still in the hatch of the International Space Station (ISS). She and Mike Barrett had just opened the door for a 6.5-hour spacewalk for maintenance when showers of icy particles erupted from the spacesuit’s connection to the ISS. The spacewalk was suspended, but the astronauts were never in danger, NASA stressed.
“This spacewalk ended prematurely due to a water leak from the service and cooling umbilicals; that’s where it’s attached to the ISS,” station program manager Dana Weigel of NASA told reporters in a teleconference Wednesday (July 17). (Astronauts’ spacesuits remain connected to the ISS’s life support systems via this umbilical system until just before exiting the hatch.)
“We’re still looking at the cause of the water leak and what we want to do to recover,” Weigel added. “We’ll go look for another opportunity where we want to do a spacewalk. It’s not time critical or urgent, so we’ll find the best, logical place to put it.”
NASA’s extravehicular mobility unit (EMU) spacesuit used for spacewalks has a design that dates back to the 1970s and was first used during the space shuttle mission STS-6 in April 1983. The EMU has a long and reliable flight history: It it’s the space suit that’s been used on all space shuttles, it’s allowed crews to operate the Hubble Space Telescope and it’s also helped astronauts build the ISS.
The EMU has replaceable parts that can be replaced and repaired. That said, it has been periodically prone to coolant leaks for various reasons in recent years. NASA suspended spacewalks for seven months in March 2022 after water was discovered in, for example, the helmet of a space suit. And a July 2013 incident prompted an investigative report and months of spacewalk suspension after Italian astronaut Luca Parmitano’s helmet filled with water while on a spacewalk.
Newer generations of NASA and private industry spacesuits emphasize better flexibility with updated materials, along with improved dimensions to suit all genders. The EMU is aimed at larger and male sizes because it was designed in an era when most astronauts were male recruits from what was then an almost single-sex military. In June, Collins Aerospace pulled out of a contract to design the newer ISS suits, saying its development plan “does not support NASA’s space station plan and mission goals.”
Related: ISS astronauts perform ‘spacewalk review’ after coolant leak in spacesuits
The cause of the latest leak is not yet known, but astronauts aboard Expedition 71 spent several hours troubleshooting the issues in recent weeks, and NASA is reviewing the information.
NASA originally planned a trio of spacewalks for June and July, but cut them to two after the June 13 spacewalk was suspended due to “spacesuit discomfort.” The second of the revised series was originally expected on July 2, but as Weigel indicated on July 17, there will be a general review of spaceflight needs in the coming months.
Spacewalking is among the “dynamic activities” the ISS hosts, Weigel noted at the same conference. Such activities occur roughly every week or 10 days, she added, including “something like landing or stopping a visitor’s vehicle, [or] spacewalk, [or] robotics.” (The ISS has several robotic arms and facilities that perform maintenance and scientific work, often under control from Earth.)
Plans in space are constantly changing, but the past few weeks have been particularly uncertain for ISS planning.
The Boeing Starliner spacecraft’s mission to the ISS for its first astronaut test flight was initially delayed from May 6 due to a helium leak, which NASA and Boeing extensively analyzed and addressed before the launch was approved. (Development efforts like this often have uncertainties because the spacecraft and systems are new to launching humans.)
After arriving at the ISS on June 6, the 10-day Crew Flight Test mission was ultimately extended indefinitely due to problems with the thrusters that delayed docking. The Starliner remains authorized to leave the ISS in an emergency, but engineers are analyzing ground tests conducted last week to better analyze the performance of the Starliner system before it is authorized for six-month operational missions as soon as 2025.
Part of the Expedition 71 crew from NASA arrived in space in March as part of SpaceX Crew-8 on a SpaceX Falcon 9 rocket. Crew-9 was scheduled to arrive in mid-August. While that timing is still in NASA’s manifest, all Falcon 9 launches were suspended last week following a problem with the Starlink satellite’s second launch stage.
SpaceX has asked the Federal Aviation Administration to allow launches to continue, but NASA says it wants to conduct its own review before allowing SpaceX to launch astronauts or cargo to the ISS. (Different Falcon 9 variants are used for astronauts and satellites.)