The International Space Station (ISS) has been a cornerstone of human space exploration since its inception, serving as a microgravity and space environment research laboratory. On March 5, 2021, NASA astronaut Kate Rubins and Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi conducted a significant spacewalk to prepare the ISS for upcoming solar array upgrades. This extravehicular activity (EVA) was part of a series of maintenance tasks aimed at enhancing the station's power generation capabilities.

Preparation for Solar Array Upgrades

In early 2021, NASA initiated a project to augment the ISS's power capacity by installing new solar arrays. These Roll-Out Solar Arrays (iROSAs) were designed to be mounted in front of the existing arrays, thereby increasing the station's total available power from 160 kilowatts to up to 215 kilowatts. This enhancement was crucial to support ongoing scientific research and future missions, including those related to NASA's Artemis program. The existing solar arrays, while still functional, had begun to show signs of degradation, as they were designed for a 15-year service life. ([space.com](

Details of the March 5, 2021 Spacewalk

The spacewalk on March 5, 2021, was the fourth of the year and marked the 236th EVA in support of ISS assembly and maintenance. The primary objectives of this spacewalk were:

  • Installation of Modification Kits: The astronauts installed modification kits on solar arrays 2B and 4B. These kits were essential for the upcoming installation of the new iROSAs. ([space.com](
  • Venting Ammonia: They vented ammonia from the Early Ammonia System, a critical component of the ISS's thermal control system. ([space.com](
  • Additional Maintenance Tasks: The crew also planned to relocate an Articulating Portable Foot Restraint (APFR) and perform other maintenance tasks. However, due to time constraints, some secondary tasks were deferred to future spacewalks. ([space.com](

The spacewalk began at 6:37 a.m. EST, with the astronauts exiting the Quest airlock. They worked for approximately 6 hours and 56 minutes, completing the primary objectives successfully. The EVA concluded at 1:33 p.m. EST. ([space.com](

Significance and Impact

This spacewalk was significant for several reasons:

  • Enhancing ISS Capabilities: By preparing the station for the new solar arrays, the crew ensured that the ISS would continue to operate efficiently, supporting a wide range of scientific experiments and international collaborations. ([space.com](
  • International Collaboration: The participation of JAXA astronaut Soichi Noguchi highlighted the ongoing international cooperation in space exploration, emphasizing the collaborative nature of the ISS program. ([space.com](
  • Record-Breaking Achievements: This EVA marked the fourth spacewalk for both Rubins and Noguchi, with Noguchi setting a new record for the most spacewalks conducted by a Japanese astronaut. ([space.com](

The successful completion of this spacewalk was a testament to the meticulous planning and execution required for ISS maintenance. It also underscored the importance of regular upgrades to ensure the station's longevity and effectiveness as a hub for scientific research and international cooperation in space.

Sources

  • NASA — ISS Spacewalk #72 - Kate Rubins & Soichi Noguchi - ISS - March 5, 2021 —
  • Space.com — Spacewalking astronauts tackle stubborn struts to prime space station for new solar arrays —
  • — NASA Space Station On-Orbit Status 28 February, 2021 – Spacewalk Completed —
  • — Replay of Kate Rubins and Victor Glover March 5, 2021 Spacewalk —
  • — NASA Space Station On-Orbit Status 4 March, 2021 – Friday Spacewalk Set —