Watch 2 NASA astronauts repair X-ray telescope on ISS during a spacewalk today

Two NASA astronauts will perform the year’s first spacewalk today (Jan. 16), and you can watch the action live.

Nick Hague and Suni Williams are scheduled to venture outside the International Space Station (ISS) today around 8:00 a.m. EST (1300 GMT), kicking off an extravehicular activity (EVA) event that’s expected to last 6.5 hours.

NASA will webcast the spacewalk live, beginning at 6:30 a.m. EST (1130 GMT). Space.com will carry the feed if the agency makes it available.

The two astronauts have a busy day ahead of them. Hague and Williams will “patch light leaks in the NICER X-ray telescope, then ready the Alpha Magnetic Spectrometer for future upgrades,” NASA officials wrote in a Jan. 15 blog post.

Related: Spacewalks: How they work and major milestones

“The experienced spacewalking duo will also replace advanced engineering hardware to maintain station orientation and provide navigation data,” the post added.

NICER (short for “Neutron Star Interior Composition Explorer”) launched to the station in June 2017 aboard a SpaceX Falcon 9 rocket. The instrument studies black holes, superdense stellar remnants known as neutron stars and other cosmic phenomena in X-ray light from its perch outside the orbiting lab.

In May 2023, however, the instrument developed the aforementioned “light leaks.” Sunlight began entering NICER through several small tears in its thermal shields, interfering with the telescope’s science work. Today’s spacewalk aims to fix that problem by installing patches that will block the leaks.

It will be the first on-orbit repair of a NASA space telescope by astronauts since the final Hubble servicing mission in 2009, agency officials said.

The Alpha Magnetic Spectrometer is a $2 billion particle detector that launched to the ISS in 2011. The instrument hunts for elusive dark matter by characterizing high-energy particles known as cosmic rays.

Hague arrived at the ISS in late September on SpaceX’s Crew-9 mission and currently serves as a flight engineer on the orbiting lab’s current Expedition 72.

Williams, the Expedition 72 commander, reached the ISS in early June with fellow NASA astronaut Butch Wilmore on the first crewed flight of Boeing’s new Starliner spacecraft. The duo’s mission was supposed to last just 10 days or so, but Starliner suffered problems with its thrusters, and NASA ultimately decided to bring the spacecraft down uncrewed in September. Williams and Wilmore will return to Earth next month with Hague and his Crew-9 crewmate, Alexandr Gorbunov of the Russian space agency Roscosmos.

This will be the fourth spacewalk of Hague’s astronaut career and the eighth overall for Williams. Hague will wear a spacesuit with red stripes, while Williams’ will be unmarked, NASA officials said.