NASA astronauts Sunita “Suni” Williams and Nick Hague ventured outside the International Space Station (ISS) on Thursday for US spacewalk 91. The spacewalk, starting from 6.30 pm IST, is expected to last approximately six and a half hours and focuses on critical maintenance and upgrades to the orbiting laboratory, NASA said.

NASA has provided live coverage of the event on NASA+, offering viewers a front-row seat to the operation. The mission underscores the ongoing efforts to maintain and enhance the capabilities of the ISS, a vital hub for scientific research and international collaboration, the space agency said.

LIVE: Two @NASA_Astronauts, Nick Hague and Suni Williams, step outside of the @Space_Station to support station upgrades, including repairs to our NICER (Neutron star Interior Composition Explorer) X-ray telescope. https://t.co/0VP296OmRY

— NASA (@NASA) January 16, 2025

US Spacewalk 91 Mission Objectives

During the spacewalk, according to NASA, Hague and Williams are tasked with a series of high-priority objectives:

1. Replacing a Rate Gyro Assembly: This critical component assists with orientation control for the ISS, ensuring its stability and functionality in orbit.

2. Installing Patches on NICER: The Neutron Star Interior Composition Explorer, an X-ray telescope, will receive protective patches to cover damaged areas on its light filters.

3. Upgrading Navigation Tools: The astronauts will replace a reflector device used for navigational data on one of the international docking adapters.

4. Preparatory Checks: Hague and Williams will inspect access areas and connector tools to ensure readiness for future maintenance work on the Alpha Magnetic Spectrometer.

Hague, serving as spacewalk crew member 1, is wearing a suit with red stripes, while Williams, as crew member 2, is in an unmarked suit. This marks Hague’s fourth spacewalk and Williams’ eighth, contributing to the overall total of 273 spacewalks conducted in support of the ISS.

Leading the operations from NASA Johnson Space Center in Houston are operations integration manager Bill Spetch, and spacewalk flight director Nicole McElroy. These experts have played a pivotal role in planning and executing the mission.

Looking ahead, the next spacewalk is scheduled for January 23, when astronaut Sunita Williams will once again step outside the station, this time along with Butch Wilmore. This mission, the 274th spacewalk for ISS assembly and maintenance, will involve the removal of a radio frequency group antenna assembly, sampling exterior surface materials for microbial analysis, and preparing a spare elbow joint for the Canadarm2 robotic arm, according to NASA.