Nasa astronauts Sunita Williams and Nick Hague embarked on a significant spacewalk outside the International Space Station (ISS) today, January 16, 2025.

This mission, designated US Spacewalk 91, is Williams' eighth career spacewalk and Hague's fourth. The spacewalk is expected to last around six and a half hours.

The primary objective of this spacewalk is to replace critical hardware and repair the Neutron star Interior Composition Explorer (NICER) X-ray telescope.

Since May 2023, NICER has faced issues with sunlight leaking through damaged thermal shields, disrupting its observations of neutron stars. To address this, the astronauts will install pie-shaped patches designed to block unwanted light and restore the telescope's functionality.

In addition to the NICER repairs, Williams and Hague will also perform several maintenance tasks, including removing outdated radio communication equipment and collecting microbial samples from the ISS’s exterior.

These efforts are part of ongoing research into fire safety in space and the effects of weightlessness on human health.

Williams, who last conducted a spacewalk 12 years ago, expressed her excitement about returning to extravehicular activities. The upcoming spacewalks represent not only a technical challenge but also a historic moment as astronauts service an X-ray telescope in orbit for the first time.

Following today's mission, Williams and Hague are scheduled for a second spacewalk on January 23, 2025, where they will continue their work on ISS upgrades.

As they float hundreds of kilometers above Earth, Williams and Hague's efforts will contribute significantly to advancing scientific research and maintaining the ISS's operational capabilities for future missions.

Source: India Today