ISS Antenna Is Back Online After a 6½-Hour Spacewalk
ESA astronaut Sophie Adenot and NASA astronaut Anil Menon installed and connected a spare Space-to-Ground Antenna outside the International Space Station on August 25, 2026. NASA’s August 25 completion update records a six-hour, 30-minute spacewalk and good power and data transmission during the initial checks, establishing that the replacement was operating rather than merely attached.
The repair restored the station’s second high-speed communications path after the original unit stopped tracking NASA’s relay satellites. An independent account of the completed repair explains that the other antenna had continued carrying voice and critical data after the failure began in November 2025, so the station was not cut off; what it had lost was communications redundancy.
Why the first repair attempt stopped
The replacement took two outings because the failed hardware resisted removal. ESA’s account of the two outings says stuck bolts and connectors delayed the work on August 18 and that the spare installed on August 25 had been stored outside the station since 2009.
During the first outing, Adenot and Menon fitted locks to stop the old antenna from rotating, removed its fasteners and disconnected its electrical lines. Several connections required more time and coordinated effort than planned, leaving too little time to retrieve, transport and mount the replacement safely.
Mission Control therefore narrowed the objectives once the failed unit was free. The astronauts secured it to the station’s truss for an extended stay, left the spare at its external storage position and returned through the Quest airlock. That stopping point completed the difficult removal without compressing the separate transport and installation sequence into the time remaining.
How the stored spare reached the active mount
The follow-up spacewalk began with Menon attaching a portable foot restraint to Canadarm2. He rode the robotic arm to the external platform holding the spare, while Adenot moved independently along handrails on the station’s exterior.
After releasing the replacement from storage, Menon held it while Canadarm2 carried him to the Z1 truss. Adenot travelled back to the same worksite, cleaned and lubricated the receiving bolt inserts, and helped place the antenna on its boom. The pair secured the assembly, completed the electrical connections, removed the locks used to immobilize it during transport and fitted its heat shield.
The spacewalkers then returned to the failed unit, released its temporary restraints and transferred it to a permanent external storage position. That left the spare in the operating location and the removed hardware secured rather than discarded; large station components generally remain outside until a later disposal or return plan is assigned.
What the high-speed antenna carries
The Space-to-Ground Antenna, commonly shortened to SGANT, connects the station with NASA’s Tracking and Data Relay Satellite constellation. Those relay spacecraft pass communications between the orbiting laboratory and Mission Control in Houston even when the station is beyond the direct view of a single ground site.
The link supports high-rate data rather than serving as a simple television dish. It carries operational communications and mission data, including the voice and critical information needed by controllers and the crew. Restoring the antenna therefore protects a working route for station operations, research traffic and other data that must move between orbit and the ground.
Initial power and data transmission were the relevant signs of a successful activation: the installed assembly was receiving power and passing information through the station’s communications system. Physical mounting alone would not have established that the antenna, its cabling and the downstream path were functioning together.
The station has its alternate path again
The ISS once again has two available Space-to-Ground antennas. If either unit becomes unavailable, the other can provide the high-speed route instead of leaving the system dependent on a single working antenna.
This is a restoration of the station’s previous architecture, not a new communications capability or an expansion beyond its earlier configuration. While the original antenna was out of service, the surviving unit prevented a total communications loss. Installing the spare removed that single point of dependence and restored tolerance for another antenna outage.
The long period between storing the spare and using it illustrates the purpose of externally mounted orbital replacement units. The station did not have to wait for a large antenna to be launched after the failure; the required hardware was already positioned on the complex, although moving it still required Canadarm2, two spacewalkers and a dedicated follow-up outing.
As of the completion updates, the replacement is installed, activated and passing power and data checks, while the failed assembly is in permanent external storage. The mounting work is complete; continuing ground observation concerns the antenna’s performance in service rather than another attempt to install it.
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