An X-ray observatory used to study neutron stars is “back in the black” and a cosmic ray detector is ready for possible future upgrades after two astronauts completed a spacewalk outside the International Space Station (ISS).

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.

At the time of writing, Williams and ISS crewmate, Nick Hague, are conducting NASA’s first spacewalk in over a year. The pair are scheduled to spend roughly 6.5 hours in the vacuum of space, where they will work on a number of long overdue external repairs and equipment assessments.

NASA astronaut Sunni Williams, one-half Boeing Starliner crew who have been stuck on the International Space Station for months, took part in a spacewalk on Thursday to do some repairs to the orbiting laboratory.

The US space agency announced Thursday that two astronauts successfully completed a spacewalk to repair the International Space Station (ISS). During the six-hour mission, astronauts Suni Williams and Nick Hague replaced faulty light filters and reflectors,

Nasa astronaut Suni Williams, one of two astronauts stuck on the International Space Station, has completed her first spacewalk since arriving.

NASA astronauts at the ISS go on a spacewalk to work on some upgrades at the site::Nick Hague and Suni Williams took in views of Earth as they undertook their work. The spacewalk is expected to go for about six hours.