Menon and Adenot Swap a Failed ISS Space-to-Ground Antenna

On Aug. 18, 2026, NASA astronaut Anil Menon and ESA astronaut Sophie Adenot went outside the International Space Station to replace a faulty Space-to-Ground antenna. It was Menon's second spacewalk and Adenot's first, making her the first French woman to walk in space. NASA's broadcast called it the 282nd spacewalk in support of ISS assembly, maintenance and upgrades, the fifth conducted from the station in 2026 and the second for Expedition 75 in 12 days. The plan was for about six and a half hours outside.

The failed antenna

The Space-to-Ground antennas, called ESCANTs, are dish-like antennas that sit side by side on the Z1 truss in the center section of the station's truss. They are part of the Ku-band system for high-data-rate communications: payload data, video, crew procedures, voice and telemetry. They point themselves at NASA's Tracking and Data Relay Satellite system.

Last November, ESCANT number two began showing periodic pointing problems during autotrack operations. The problems worsened, and the broadcast described a failed gimbal assembly, meaning the dish can no longer point toward the relay satellites. Flight controllers switched to ESCANT number one, which was working perfectly. Replacing number two was meant to restore full redundancy.

Both antennas are legacy hardware. The first Space-to-Ground antenna on Z1 arrived on STS-92 in October 2000. The failed unit was delivered on STS-132 in May 2010 and installed by Garrett Reisman and Steve Bowen. The spare, delivered on STS-127, was installed on external stowage platform 3 (ESP-3) by Dave Wolf and Tom Marshburn on July 20, 2009, the 40th anniversary of the Apollo 11 landing. That spare was the only one left aboard.

The plan

Menon wore the suit with red stripes as EV1, and Adenot the unmarked white suit as EV2. Menon was to retrieve an articulating portable foot restraint from ESP-2 and attach it to the end of Canadarm2, then be moved between work sites, likened in the broadcast to a repairman on a cherry picker. Jack Hathaway was the prime robotics operator, assisted by Jessica Meir, who also helped suit the crew with Hathaway.

The sequence called for installing gimbal locks over the dish, then disconnecting two electrical connectors and releasing four bolts that hold the antenna to the boom. Menon would carry the failed antenna to temporary stowage, fetch the spare from ESP-3 on the P3 truss by releasing two bolts, and bring it back to Z1 for installation. The failed unit would then be stowed on ESP-3, where it may eventually be returned to Earth for upgrades and repairs. The gimbal locks are physical pins that secure the antenna's movable joints during handling. There were 12 in all, in two sets: one of four bolts and one of eight.

In Houston, Chris Dobbins was flight director. Anne McClain was the intravehicular crew member talking to the spacewalkers, Steven Zenter and Kathy Bolt served as spacecraft communicators, and Sandy Fletcher was the spacewalk officer. Chloe Mehring was named as flight director for the Aug. 25 spacewalk.

Getting outside

Before the walk, the crew breathed pure oxygen to purge nitrogen from their blood and did light in-suit exercise to prevent decompression sickness. Their suits had passed a leak check that morning. Hathaway and Meir installed SAFER backpacks, small nitrogen-jet units that could return a crew member to the station if they became untethered.

Before the crew lock depressurized, Meir asked about black smudges on an O-ring of Medox canister 006. Controllers judged it a slight discoloration and were content to proceed.

The crew lock was brought down in steps, first to about 5 psi from 14.7, with a pause for suit checks and a leak check, then on toward vacuum. Menon and Adenot read out their tether configurations, which the ground described as among the clearest they had heard. The suits went to battery power at 7:29 a.m. CDT (8:29 a.m. EDT), the official start, slightly ahead of the published time. During hatch operations, controllers briefly held the crew for an LED on the PSA and ran a recovery from fault; they said it did not affect the spacewalkers. Menon opened the thermal cover and reported six Sharpie lines, then exited. Adenot was told to do some translation adaptation, "Welcome to space," and replied that she felt very good.

Work at Z1

Adenot reached the Z1 work site about 38 minutes in and removed the heat shield from the antenna group interface tube, the part of the boom that houses the electronics. She reported discoloration on the shield, which she suspected came from intense sunlight on the forward side, with the beginning of the same pattern on the aft side along the cross-pattern of the thread. She said there was no risk of the shield flying off, folded it inside out so it would not be damaged further and stowed it in the bag.

Menon installed the foot restraint on Canadarm2 and ingressed it. Meir and Hathaway moved the arm to positions such as the Z1 backoff position and then the bolt access position. The ground noted the escant's maximum load of 45 pounds (28 kg).

Gimbal lock one, the four-bolt lock on the aft side, did not seat easily. Adenot found the two top bolts too high when the two bottom ones were positioned, and about a centimeter of difference in distance. Menon, from the arm, described the antenna as about 15 degrees angled away from the gimbal lock. Adenot's view was that the antenna was too tall. Houston agreed it was a good call to wait and that she could not have resolved it alone. Once Menon was in position with the arm bringing his body in, he kept about a meter of clearance from the dish and the two got two turns on the bolts; a controller remarked there was "much joy in MCC."

The bolts were then driven with a pistol grip tool using a 2-inch extension, with turn counts and torque reported. Bolt Charlie gave low-torque faults at first, after two hand turns and four more turns. The ground did not think it was a calibration problem. After the crew braced the tool more firmly, a green torque light came up with actual torque of 12, for seven turns in total including the hand turns, and the ground called Charlie a good bolt. Bravo took four turns with a green light, and Delta four and a half turns at 12 torque. A further bolt took four and three-quarter turns at 12.1 torque. Controllers asked the crew to wait for a go between bolts while they did the math on the ground. They then moved on to gimbal lock number two, with all eight bolts hand-started two turns each. About an hour and 42 minutes into the walk, the crew was still working on that second lock.