NASA's next spacewalk: Astronauts set for nearly seven hours outside the space station

Two NASA astronauts are preparing for a lengthy spacewalk outside the International Space Station (ISS) to carry out a crucial repair on one of the orbiting laboratory's most important pieces of equipment.

NASA has scheduled the mission for June 30, with astronauts Chris Williams and Jessica Meir expected to spend about six hours and 40 minutes in the vacuum of space replacing a malfunctioning wrist joint on Canadarm2, the station's Canadian-built robotic arm. The spacewalk is set to begin at 8:35 a.m. EDT (6:05 p.m. IST).

The repair is considered essential because Canadarm2 plays a key role in station operations, including moving equipment, supporting maintenance activities and assisting visiting spacecraft. The robotic arm has been in service for more than 25 years, making it one of the ISS's most heavily used systems.

Following an investigation by NASA and the Canadian Space Agency (CSA), engineers determined that the damaged wrist joint must be replaced to restore the arm's full mobility. A spare component already stored aboard the station will be installed during the operation.

Astronauts have spent recent days preparing for the challenging task. Williams completed a spacesuit checkout inside the Quest airlock with assistance from European Space Agency astronaut Sophie Adenot, verifying communications, mobility and life-support functions ahead of the excursion.

Williams and Meir have also rehearsed the repair sequence using detailed simulations while inspecting and servicing the emergency jet-pack systems attached to their spacesuits. Meir additionally readied specialised pistol-grip tools that will be used during the repair work in microgravity.

Inside the station, Adenot and NASA astronaut Jack Hathaway have been practising support procedures for the mission. Their responsibilities include operating Canadarm2 from within the ISS and positioning it to facilitate the replacement work.

While preparations continue for the spacewalk, other crew members remain engaged in scientific research. Recent activities aboard the station have included the deployment of student-built CubeSats, studies examining the effects of long-duration spaceflight on eye health, and experiments exploring how artificial intelligence could improve efficiency and communication during future missions.