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Soyuz MS-26 mission

A Soyuz-2-1a rocket lifted off from Baikonur Cosmodrome, Kazakhstan, on Sept. 11, 2024, sending the Soyuz MS-26 spacecraft with a crew of three on its way to the International Space Station, ISS, for a nearly six-month stay.

Previous mission: Soyuz MS-25

Soyuz MS-26 mission at a glance:

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Soyuz MS-26 mission

The Soyuz MS-26 spacecraft (Production Vehicle No. 757), intended to deliver three members of Expedition 71 and 72 to the ISS, originally included veteran Roskosmos cosmonauts Aleksei Ovchinin and Ivan Vagner. On March 27, 2024, NASA publicly confirmed that its veteran astronaut Don Pettit would launch aboard Soyuz MS-26, as a member of ISS Expeditions 71 and 72.

In March 2023, Roskosmos also reported that Sergei Ryzhikov, Aleksei Zubritsky and Aleksandr Gorbunov had been assigned as a backup crew for Expedition 72. Ryzhikov's crew was also expected to serve as the primary crew on the first Russian launch to the ISS in 2025.

Soyuz MS-26 launch campaign

After post-production tests in Korolev in the Fall of 2023, Soyuz MS-26 was shipped to Baikonur Cosmodrome on Dec. 18, 2023. It was unloaded at the processing site at Site 254 in Baikonur on Dec. 25, 2023. Within next 24 hours, RKK Energia team at Site 254 removed Soyuz MS-26 from storage and began its processing for launch.

In turn, the Soyuz 2-1a launch vehicle for the mission was reported arriving at the Tyuratam train station serving the space center aboard a 28-car train on June 25, 2024. (The same transport also delivered components of the rocket for the Progress MS-29 cargo mission).

On Aug. 26, 2024, the primary and backup crews arrived at Baikonur for familiarization training inside the flight-worthy Soyuz MS-26, which took place on August 28 inside the Spacecraft Processing Building, MIK KA, at Site 254. Part of the exercise was performed with cosmonauts donning Sokol-KV2 pressure safety suits.

On Sept. 1, 2024, Soyuz MS-26 was connected to its launch vehicle adapter after being weighted and being prepared for loading of the final cargo. The spacecraft was then rolled inside its payload fairing assembly and rotated back into vertical position for final tests.

On September 5, the primary and backup crews again took turns taking seats inside Soyuz MS-26 in its launch configuration, checking the composition and placement of deliverable items inside the Reentry and Habitation modules. They also tested the operation of key systems in simulation mode. On the same day, specialists from RKK Energia unplugged the vehicle from the diagnostics equipment in preparation for its transfer to the launch vehicle assembly building at Site 31 for integration with its Soyuz-2-1a launch vehicle which was completed on September 6. On the same day, the State Commission overseeing the campaign authorized the rollout of the vehicle to the launch pad at Site 31 on Sept. 8, 2024, which took place in the morning hours of the day.

Soyuz MS-26 launch scenario

A Soyuz-2-1a rocket with the Soyuz MS-26 spacecraft lifted off as scheduled on Sept. 11, 2024, at 19:23:12.436 Moscow Time (12:23 p.m. EDT).

Propelled by the simultaneous thrust of the four engines of the first stage and the single engine of the second stage, the vehicle headed almost exactly east to align its ascent trajectory with an orbital plane inclined 51.6 degrees toward the Equator. Slightly less than two minutes into the flight (L+113.70 seconds), at an altitude of around 45 kilometers and a velocity of 1.75 kilometers per second, the ship's main emergency escape rocket was jettisoned, immediately followed by the separation of the first stage. The emergency escape rocket and the four boosters of the first stage were expected to impact the ground 330 and 350 kilometers downrange from the launch site respectively.

Around 35 seconds after the first stage separation (L+153.90 seconds), as the vehicle exited the dense atmosphere at an altitude of 79 kilometers and a velocity of 2.2 kilometers per second, the payload fairing protecting the spacecraft split into two halves and fell away. They were projected to fall 500 kilometers downrange from the launch site.

In the meantime, the second (core) stage of the rocket continued firing until 4.8 minutes into the flight (L+287.70 seconds). Moments before the second stage completed its work, the four-chamber engine of the third stage ignited, firing through the lattice structure connecting the two stages. Moments after the separation of the core booster at an altitude of 157 kilometers and a velocity of 3.8 kilometers per second, the aft skirt of the third stage split into three segments and separated as well. The second-stage booster and the sections of the aft skirt were to impact the ground 1,550 and 1,570 kilometers downrange from the launch site respectively.

Following the 8-minute 49-second climb to orbit, the propulsion system of the third stage was cut off at L+525.93 seconds into the flight, releasing Soyuz MS-26 into an initial orbit at 19:32:01 Moscow Time (12:32 p.m. EDT).

Rendezvous and docking operations

Soyuz MS-26 was scheduled to dock at the nadir (Earth-facing) docking port of the Rassvet module, MIM1, a part of the Russian ISS Segment, on Sept. 11, 2024, at 22:33 p.m. Moscow Time (3:33 p.m. EDT), after a more than three-hour, two-orbit autonomous flight.

The ISS passed over the Baikonur launch site 20 seconds after the liftoff of Soyuz MS-26 and by the time the crew vehicle reached orbit, the station was more than 1,000 miles ahead in a 415.278 by 436.322-kilometer orbit. During the second orbit of its mission, Soyuz MS-26 was projected to be in a 389.816 by 426.712-kilometer intercept orbit. As usual, the final autonomous rendezvous process included six engine burns aboard the transport vehicle, which had the following timeline during the Soyuz MS-26 mission:

According to the Russian mission control in Korolev, the autonomous rendezvous of Soyuz MS-26 on Sept. 11, 2024, had the following timeline:

• 20:12:28 Moscow Time: Beginning of autonomous rendezvous with the ISS;
• 21:01:42 Moscow Time: Activation of the Kurs rendezvous system aboard the Zvezda Service Module, SM;
• 21:02:42 Moscow Time: Activation of the Kurs rendezvous system aboard Soyuz MS-26;
• 22:15 — 22:20 Moscow Time: Fly-around of the station;
• 22:20 — 22:21 Moscow Time: Station-keeping of the spacecraft near ISS before final approach;
• 22:21 — 22:33 Moscow Time: Final approach to the Rassvet module, MIM1;
• 22:33:03 Moscow Time: Contact.

The 54-degree, three-minute flyaround of the station began from a distance of around 400 meters to align the spacecraft with the nadir-facing docking port of the Rassvet module. The spacecraft then started the final approach from a distance of around 200 meters.

The actual contact and capture between the transport ship and the station was reported to take place at 22:32:09 Moscow Time on Sept. 11, 2024.

The hatches between the crew vehicle and the station were opened at 00:58 Moscow Time on Sept. 12, 2024, (5:58 p.m. EDT on September 11).

The arrival of the Soyuz MS-26 spacecraft temporarily increased the ISS population from nine to 12 people. Counting three astronauts aboard the Chinese space station and four people conducting the autonomous Polaris Dawn flight aboard the Crew Dragon spacecraft, a record-breaking number of 19 people was in the Earth's orbit at the same time.

VKD-63 spacewalk

On Dec. 19. 2024, members of the Soyuz MS-26 crew Aleksei Ovchinin and Ivan Vagner were scheduled to conduct a six-and-a-half-hour sortie on the Russian ISS Segment. The main objective of the VKD-63 spacewalk is the installation of the SPIN-X1-MVN spectrometer on the exterior of the Zvezda Service Module, SM. The hatch opening was scheduled for around 18:10 Moscow Time (10:10 a.m. EST) and the spacewalk was to continue until 00:50 Moscow Time on Dec. 20, 2024, (6:50 p.m. EST on December 19).

Soyuz MS-26 lands

As originally scheduled, Soyuz MS-26 began its return to Earth on April 19, 2025. Aboard was the same crew that rode the vehicle into orbit: Roskosmos cosmonauts Aleksei Ovchinin and Ivan Vagner, as well as NASA astronaut Don Pettit. Coincidently, the Soyuz MS-26 landing came on Pettit's 70th birthday.

The hatches between the Rassvet module, MIM1, and the Soyuz MS-26 were scheduled to close between 21:35 and 21:55 Moscow Time on April 19 (2:35 p.m. – 2:55 p.m. EDT). NASA confirmed that the hatches between the crew vehicle and the station had been closed as planned at 2:52 p.m. EDT.

According to the Russian mission control, the ISS departure operations had the following timeline on April 19-20, 2025:

• 21:50:00 Moscow Time: Closing of transfer hatches;
• 22:00 — 23:00 Moscow Time: Transfer hatches leak checks, suiting-up operations;
• 23:00 — 23:39 Moscow Time: Crew transfer to the Descent Module, closing of a hatch between the Descent Module and the Habitation Module;
• 23:39 — 00:08 Moscow Time: Pressure suits leak checks;
• 00:08 — 00:44 Moscow Time: Leak checks in the hatch between the Descent and Habitation modules.

The undocking of the spacecraft from the ISS took place as scheduled on April 20, 2025, at 00:57 Moscow Time (5:57 p.m. EDT on April 19). It marked the end of Expedition 72 and start of Expedition 73 aboard the ISS. At the time of undocking, the ISS was flying over Southern Mongolia, within view of Russian ground stations, in a 438.7 by 414.8-kilometer orbit with an inclination 51.7 degrees toward the Equator.

After around 2.5 hours in the autonomous flight and at a distance, Soyuz MS-26 initiated a 4-minute 41-second braking maneuver at 03:27:08 Moscow Time on April 20 (8:27 p.m. EDT on April 19), while flying over Southern Atlantic, east of the Argentinean Coast. The engine firing, lasting until 03:31:49 Moscow Time, slowed down the vehicle by 128 meters per second, enough to leave orbit and begin the entry into the Earth's atmosphere. In the course of the maneuver, the vehicle's altitude dropped from 442 kilometers to 431.9 kilometers.

Once on a reentry trajectory, the Descent Module, SA, carrying the crew, separated from the Habitation Module, BO, and the Instrument Module, PAO, at 03:54:58 Moscow Time on April 20 (8:54 p.m. EDT on April 19) at an altitude of around 140 kilometers. The Descent Module then hit the dense atmosphere to initiate automated aerodynamic reentry at 03:57:51 Moscow Time on April 20 (8:57 p.m. EDT on April 19).

Upon dissipating much of its velocity, the capsule's parachute system waas activated at an altitude of around 10 kilometers, with its main parachute deploying at 04:06:18 Moscow Time on April 20 (9:06 p.m. EDT on April 19).

According to Roskosmos, the Descent Module of Soyuz MS-26 landed at 04:20:46 Moscow Time on April 20, 2025, (9:20 p.m. EDT on April 19), just two seconds behind schedule, near the planned location 147 kilometers south-east of Dzhezkazgan in Kazakhstan. The latest coordinates of the projected landing point issued before landing were at 47 degrees 19 minutes North latitude, 69 degrees 33 minutes East longitude. (The actual landing site was reported to be at 47 degrees 23 minutes North latitude and 69 degrees 29 minutes East longitude).

The planned touchdown was timed to take place around 56 minutes after the local sunrise, giving the search and rescue services maximum daylight time for the crew recovery.

The capsule ended on its side after landing, probably due to high winds in the area.

According to the Russian authorities, a total of 11 aircraft were dispatched to support search and rescue operations during the Soyuz MS-26 landing, including one An-26 and two An-12 planes and eight Mi-8 helicopters. Six search and evacuation trucks and 15 ground vehicles were also involved.

All three crew members were extracted from the capsule, but a cameraman present at the landing site was instructed to avoid showing NASA astronaut Don Pettit, who appeared to be in bad shape during the extraction. He only briefly appeared on camera, while being carried away from the capsule by recovery personnel. Pettit could be seen opening his helmit visor, after which he seemingly closed his eyes, rolled back his head and no longer moved.

A NASA commentator also avoided commenting on Pettit's condition during the live coverage of the recovery operation. All three crew members were reportedly taken to a medical tent deployed at the landing site, which is a routine precedure after the extraction, however, there was no visual confirmation that Pettit was inside the tent at the time when Russian crew members were brought there.

The two Russian cosmonauts appeared to be in normal condition after landing, taking into account their long-duration flight.

After several hours of uncertainty, NASA confirmed that Don Pettit had being doing well and in the range of what was "expected for him following the return to Earth." On the morning of April 20, NASA published a photo of Pettit being carried from the capsule, where he appeared in good shape under the circumstances.

Soyuz MS-26 crew members:

This page is maintained by Anatoly Zak; last update: April 20, 2025

Page editor: Alain Chabot; last edit: September 11, 2024

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Soyuz MS-26 is lowered in horizontal position ahead of its integration with a payload fairing. Click to enlarge. Credit: Roskosmos

The primary crew of the Soyuz MS-26 spacecraft during a familiarization exercise in Baikonur (left to right): NASA astronaut Don Petit, Soyuz commander Alesei Ovchinin and flight engineer Ivan Vagner, both from Roskosmos. Click to enlarge. Credit: Roskosmos

The backup crew of the Soyuz MS-26 (left to right): NASA astronaut Jonathan Kim, Soyuz commander Sergei Kud'-Sverchkov and flight engineer Aleksei Zubritsky. Click to enlarge. Credit: Roskosmos

The third stage of the Soyuz-2-1a rocket for the Soyuz MS-26 mission is being prepared for integration with the rest of the launch vehicle. The booster had an insignia dedicated to the city of Kirov (previously Khlynov and Vyatka). Click to enlarge. Credit: Roskosmos

Soyuz MS-26 arrives at launch pad at Site 31 in Baikonur. Click to enlarge. Credit: Roskosmos