NASA astronauts Sunita Williams and Nick Hague stepped outside the International Space Station (ISS) today for a vital mission, marking Williams’ eighth spacewalk and Hague’s fourth. Their objective focused on essential repairs, showcasing their expertise and commitment to the job.

The spacewalk, designated US Spacewalk 91, took place on January 16, 2025. This was Williams’ first spacewalk in 12 years, while Hague added a fourth accomplishment to his impressive track record. Together, they initiated a six-and-a-half-hour operation aimed at repairing critical systems on the ISS.

Their tasks included maintaining equipment for the station’s orientation, upgrading the Neutron Star Interior Composition ExploreR (NICER) telescope, and replacing a reflector on a docking adapter, as well as preparing tools for future work on the ISS. Williams, an accomplished astronaut, expressed her enthusiasm as she exited the station by radioing, “I’m coming out,” signalling her return to spacewalking duties.

Williams and her fellow astronaut Butch Wilmore were initially scheduled to return in June 2024 after a week-long mission aboard Boeing’s Starliner, but technical issues with the spacecraft forced an extended stay. NASA has since rescheduled their return for March or April. Additionally, safety concerns related to SpaceX’s Crew-10 mission have further delayed their plans. Nevertheless, the astronauts have adjusted well to life aboard the ISS.

NASA’s Flight Director, Nicole McElroy, commended the crew for their thorough preparations for the spacewalks. “The crew has studied the tasks and is fully ready,” McElroy noted.

Williams will join Wilmore for another spacewalk next week, where they will focus on removing an antenna assembly and collecting surface samples to study microorganisms on the station’s exterior. They will also prepare a spare elbow joint for the Canadarm2 robotic arm. NASA emphasizes that these activities are crucial for the upkeep of the station, with each spacewalk anticipated to last around six and a half hours.

Williams’ extensive experience continues to shine during these demanding missions, highlighting the resilience and skill required for space exploration.

The Indian Space Research Organisation (ISRO) has successfully conducted the SpaDeX docking experiment, marking a significant advancement in India’s space capabilities. Early on Thursday, January 16, 2025, ISRO joined the ranks of the USA, Russia, and China by mastering the complex technology required for spacecraft docking in orbit.

Launched on December 30, 2024, by the PSLV C60, the two satellites involved in the experiment, SDX01 (Chaser) and SDX02 (Target), reached their designated positions and executed a flawless docking maneuver. This operation was closely monitored by the team at ISRO’s Mission Operations Complex (MOX) at the Telemetry, Tracking, and Command Network (ISTRAC).

Celebrating this achievement, ISRO shared on social media, “Docking Success Spacecraft docking successfully completed! A historic moment. India became the 4th country to achieve successful space docking. Congratulations to the entire team!”

Following the successful docking, ISRO has maintained control over the newly unified satellite structure and plans to conduct undocking and power transfer tests in the forthcoming days. This mission, beyond its immediate success, aims to lay the groundwork for more ambitious endeavors such as manned lunar missions, sample returns from the moon, and potentially an Indian Space Station.

The SpaDeX mission also serves as a demonstration of vital technologies like electrical power transfer between docked spacecraft, which will be crucial for future in-space robotic operations and composite spacecraft management post-undocking.

ISRO stated that the next steps involve validating the docking process through ground simulations and ensuring the mission’s objectives continue smoothly with subsequent experiments planned over the mission’s expected life span of up to two years.

This milestone not only demonstrates ISRO’s growing capabilities in space technology but also promises to bolster India’s position in future international space exploration initiatives.

In a historic step towards establishing its own space station, the Indian Space Research Organisation (ISRO) launched the Space Docking Experiment (SpaDeX) from Sriharikota on December 30, 2024. This groundbreaking mission aims to demonstrate India’s capability to dock two satellites in orbit, a feat achieved so far only by the United States, Russia, and China.

The SpaDeX mission, executed aboard the reliable PSLV-C60 rocket, successfully deployed two spacecraft, SDX01 and SDX02, into a low-Earth orbit approximately 475 kilometers above Earth. Over the following days, these satellites, designated as the “Chaser” and the “Target,” will perform precise maneuvers for docking, undocking, and interlocking, with real-time control by ISRO scientists in Bengaluru.

A leap towards Bharatiya Antriksh Station

SpaDeX is integral to India’s ambitious space station project, the Bharatiya Antriksh Station, slated for completion by 2035. The mission marks a significant step in developing technologies for rendezvous and docking, essential for constructing and operating a space station.

Currently, only two space stations exist—the International Space Station (ISS), a collaboration between NASA, Roscosmos, and ESA, and China’s Tiangong Space Station. With Bharatiya Antriksh Station, India aspires to join this elite league.

Critical objectives of SpaDeX

The primary goals of SpaDeX include:

1. Demonstrating docking technology to ensure seamless interlocking and pressure checks between spacecraft.
2. Electric power transfer between docked spacecraft, paving the way for advanced in-space operations.
3. Composite spacecraft control, enabling remote and automated management from mission control.
4. Payload experiments post-undocking, ensuring optimal utilization of resources.

These advancements will also enhance the docking capability of India’s Reusable Launch Vehicle (RLV), akin to NASA’s space shuttles, for future missions.

Microgravity experiments with POEM-4

In tandem with SpaDeX, ISRO is conducting microgravity experiments using the PSLV’s fourth stage, termed POEM-4 (PSLV Orbital Experimental Module-4). This platform hosts 24 payloads, including a robotic arm to simulate debris capture—a crucial capability for future space station operations.

The microgravity experiments will benefit academia, startups, and ISRO’s own research centers, providing invaluable insights for extended-duration missions.

Inspiration from “Interstellar”

Docking in space is a complex maneuver, vividly dramatized in the sci-fi film Interstellar. Similar to the movie’s high-stakes scenario, ISRO’s mission involves the Chaser spacecraft approaching and interlocking with the Target while both orbit Earth at high speeds.

Pioneering India’s space future

The SpaDeX mission is not just a technological milestone but a testament to India’s growing prowess in space exploration. If successful, it will cement India’s position as a leader in cutting-edge space technology, bringing the nation closer to realizing its space station dream.

By leveraging such innovations, ISRO continues to push boundaries, inspiring the next generation of scientists and contributing to global advancements in space research.