Soyuz MS-27 Reaches the ISS in Record Time – Here’s How

On April 8, 2025, at 5:47 UTC — right on schedule — a Soyuz 2.1a rocket lifted off from the Baikonur Cosmodrome, carrying the crew of the Soyuz MS-27 mission: Russian cosmonauts Sergey Ryzhikov and Alexey Zubritsky, along with NASA astronaut Jonathan Kim. The trio is set to spend approximately eight months aboard the International Space Station (ISS).

Soyuz MS-27 launch from baikonur. Credits: Roscosmos

After just over three hours — 3 hours and 10 minutes, to be precise — the spacecraft successfully docked with the Prichal module on the ISS. This marks the 157th crewed flight of a Soyuz spacecraft since its debut in 1967 and the 27th mission of the modern MS variant.

Soyuz MS-27 docking, after only 3h10′ at Prichal node. Credits: Roscosmos

The ISS Express: 3 Hours, 10 Minutes

This rapid rendezvous was made possible by Soyuz’s highly sophisticated autonomous navigation system, combined with an ideal orbital alignment of the ISS during its pass over the Kazakh launch site. The ISS, orbiting at an inclination of 51.6° to the equator, was positioned such that after just one and a half orbits, it intersected perfectly with the Soyuz flight path. The spacecraft’s powerful engines and navigation system took care of the rest — though such optimal conditions are not always guaranteed.

ISS orbital inclination and Soyuz Trajectory. Credit. Roscosmos — *ISS orbital inclination and Soyuz Trajectory. Credits: Roscosmos*

In less favorable scenarios, the mission follows a multi-orbit rendezvous profile, extending the docking time to around eight hours. Still, that’s significantly faster than the 25-hour rendezvous typically required by SpaceX’s Crew Dragon.

One important factor in this time advantage is propulsion. While both the Falcon 9 and Soyuz 2.1a launchers offer similar performance, the Soyuz spacecraft features more capable orbital engines, giving it a quicker climb to the station. Moreover, unlike its cargo version Progress, the crewed Soyuz does not need to conserve propellant for ISS refueling operations — allowing for more aggressive maneuvers.

In situations requiring manual control — for example, in the event of a navigation system failure — Soyuz can switch to a low-consumption docking profile. Thanks to its design, inherited from the original Soviet lunar program, Soyuz includes a habitation module (the spherical BO section at the front), where the crew can comfortably wait without staying confined in their Sokol suits. This module even includes a toilet and a small galley.

Meet the Crew

As part of the ongoing crew exchange agreement between Roscosmos and NASA, Soyuz MS-27 includes two Russian cosmonauts and one American astronaut:

Jonathan “Jonny” Kim is making his space debut. Born in 1984 in Los Angeles, he is a Navy SEAL officer and medical doctor, and joined NASA in 2020.

Commander Sergey Ryzhikov is on his third spaceflight. Born in 1974 in Tatarstan, he is a Lieutenant Colonel in the Russian Air Force. He previously flew aboard Soyuz MS-02 and MS-17, spending a total of 358 days, 14 hours, and 2 minutes in space, and completed a 6 hour and 48 minute EVA.

Alexey Zubritsky, a Lieutenant in the Russian Air Force, is also flying to space for the first time. Born in 1992 in Zaporizhia, he was recruited by Roscosmos in 2018.

Soyuz MS-27 crew. From left: Jonathan Kim (Nasa), Sergey Ryzhikov (Roscosmos) and Alexey Zubritsky (Roscosmos). Credit: Roscosmos — *Soyuz MS-27 crew. From left: Jonathan Kim (NASA*), Sergey Ryzhikov (Roscosmos), *and Alexey Zubritsky (Roscosmos). Credits: Roscosmos*

Crew Swaps and International Cooperation

On April 7, a high-level meeting took place in Baikonur between Dmitri Bakanov, the new CEO of Roscosmos, and Kenneth Bowersox, NASA’s Deputy Administrator. Discussions focused on ongoing cooperation to maintain ISS operations through at least 2028, and future joint plans — including those proposed by Kirill Dmitriev of Russia’s Investment Fund.

For years, NASA and Roscosmos have maintained a reciprocal crew exchange program: every Crew Dragon carries a Russian cosmonaut, and every Soyuz includes a NASA astronaut. This ensures that someone on board the ISS is always capable of operating both spacecraft types and can oversee their respective modules, maintaining uninterrupted functionality of onboard systems.

These agreements — regularly renewed — were especially vital during the period of political tension following the Russian invasion of Ukraine. They continue to promote a peaceful, cooperative environment on the ISS. The current agreement runs through 2026, but both agencies are working toward extending it to at least 2028. During the April 7 meeting, officials also began discussing plans for the retirement of the ISS, currently scheduled for 2030.

^{*Cover image credits: Roscosmos}