Soyuz MS-10 was a crewed Soyuz MS spaceflight which aborted shortly after launch on 11 October 2018 due to a failure of the Soyuz-FG launch vehicle boosters. MS-10 was the 139th flight of a Soyuz spacecraft. It was intended to transport two members of the Expedition 57 crew to the International Space Station. A few minutes after liftoff, the craft went into contingency abort due to a booster failure and had to return to Earth. By the time the contingency abort was declared, the launch escape system (LES) tower had already been ejected and the capsule was pulled away from the rocket using the launch escape solid rocket motors on the capsule fairing. Both crew members, Roscosmos cosmonaut Aleksey Ovchinin and NASA astronaut Nick Hague, were recovered alive and in good health. The MS-10 flight abort was the first instance of a Russian crewed booster accident in 35 years, since Soyuz T-10-1 exploded on the launch pad in September 1983. On 1 November 2018, Russian scientists released a video recording of the mission.

A few minutes after liftoff, which took place at 08:40 UTC, the crew reported feeling weightless, and mission control declared a booster had failed. According to Sergei Krikalyov of Roscosmos, the primary cause of the failure was a collision that occurred during the separation of the carrier rocket's first and second stages. "A deviation from the standard trajectory occurred and apparently the lower part of the second stage disintegrated," he said. Shortly after, a contingency was declared and the spacecraft carrying the crew performed an emergency separation, returning to Earth in a ballistic trajectory, during which the crew experienced "about six to seven times Earth's gravity" followed by a successful landing. The abort occurred at an altitude of approximately 50 kilometres (31 miles); the spacecraft reached an apogee of 93 km (58 mi) then landed 19 minutes and 41 seconds after launch. At 08:55 UTC the search and rescue team was deployed to recover the crew and the spacecraft, which had landed 402 kilometres (250 mi) from the launch site and 20 kilometres (12 mi) east of Jezkazgan, Kazakhstan. Approximately 25 minutes after the search and rescue team took off, NASA announced they were in contact with Ovchinin and Hague. NASA TV broadcast photographs of the crew undergoing medical tests and apparently healthy at Jezkazgan Airport at 12:04 UTC. The crew flew to the Baikonur Cosmodrome to meet their families before leaving for Moscow.

The cause of the launch abort has been preliminarily identified as the failure to jettison one of the four 1st stage boosters at 119 seconds. The booster then collided and damaged the second stage thus triggering the flight termination and the activation at 124 seconds of the lower escape system. Due to the relative low altitude at which the ballistic reentry started, Ovchinin and Hague experienced only a little spin to stabilize the capsule during descent and acceleration of just about 6g, which is less than every candidate for a space mission has to endure during training.

The launch vehicle Soyuz-FG is produced in Samara by the Russian Space Center (RCC) Progress, which is part of Roscosmos. So far, 64 launches of this modification of the Soyuz rocket were made, all were successful, the last one took place on June 6, 2018. The Soyuz MS spacecraft is produced by RSC Energia in the Moscow region near Korolev. The Soyuz MS-10 launch as well as its docking with the ISS were insured by Soglasie for the amount of 4.65 billion rubles.

To summarize, the sequence of events during the Soyuz MS-10:

114s – Escape system tower (DU SAS) jettison

118s – End of burn of the four 1st stage boosters.

119s – Oxygen tank valve of one of the 1st stage boosters fail-close. Booster collides and damages the central core.

124s – Central core stage engine shuts down. RDG carries Orbital Module and Descent Module away from the rocket.

160s – Descent Module separates from Orbital Module and starts ballistic reentry.

Around 6:10 a.m. EDT on October 11, NASA reported that the crew was out of the capsule and that rescue personnel had reached the landing site, assisting the crew with post-landing operations.

According to TASS, quoting a statement from the Central Military District, TsVO, whose personnel was responsible for search and rescue, the PEM-1 amphibious vehicle was used to turn the capsule in order to free the ship's blocked forward hatch before the crew could be extracted.

TsVO's An-26 aircraft dropped military parachutists at the site, who reached the spacecraft before the arrival of the helicopters. Medics examined the crew and found them in a satisfactory condition, TASS said. Aircraft and ground vehicles based in Dzhezkazgan, Baikonur and Karaganda initiated search operations soon after the accident. Within an hour, four Mil-8 helicopters and a ground-based team reached the Descent Module.