Soyuz MS-25

Soyuz MS-25, Russian production No. 756 and identified by NASA as Soyuz 71S, was a Russian crewed Soyuz spaceflight from Baikonur Cosmodrome to the International Space Station.^[5][6]

Soyuz MS-25

Soyuz MS-25 illuminated by an aurora
Names	ISS 71S
Mission type	ISS crew transport
Operator	Roscosmos
COSPAR ID	2024-055A
SATCAT no.	59294
Mission duration	183 days, 23 hours, 22 minutes and 54 seconds
Distance travelled	126,000,000 km (78,000,000 mi)[1]
Orbits completed	2,944[1]
Spacecraft properties
Spacecraft	Soyuz MS-25 No. 756[2]
Spacecraft type	Soyuz MS
Manufacturer	Energia
Launch mass	7,152 kg (15,767 lb)[2]
Crew
Crew size	3
Members	Tracy Caldwell Dyson
Launching	Oleg Novitsky Maryna Vasileuskaya
Landing	Oleg Kononenko Nikolai Chub
Callsign	Kazbek
Start of mission
Launch date	23 March 2024, 12:36:10 (2024-03-23UTC12:36:10Z) UTC[3]
Rocket	Soyuz-2.1a No. 15000-066[2]
Launch site	Baikonur, Site 31/6
Contractor	RKTs Progress
End of mission
Landing date	23 September 2024, 11:59:04 (2024-09-23UTC11:59:05Z) UTC[4]
Landing site	Kazakh Steppe, Kazakhstan (47°21′00″N 69°38′00″E)[4]
Orbital parameters
Reference system	Geocentric orbit
Regime	Low Earth orbit
Inclination	51.66°
Docking with ISS
Docking port	Prichal nadir
Docking date	25 March 2024, 15:02:51 UTC[2]
Undocking date	23 September 2024, 08:36:30 UTC[4]
Time docked	181 days, 17 hours, 33 minutes and 39 seconds
Mission patches: launch (left) and landing (right) Top: launching crew, from left: Dyson, Novitsky, and Vasileuskaya Bottom: landing crew, from left: Kononenko, Chub, and Dyson Soyuz programme ← Soyuz MS-24 Soyuz MS-26 →

Crew

MS-25 saw was the first launch of two women, Tracy Caldwell-Dyson from the United States and Maryna Vasileuskaya from Belarus,^[7] aboard a Soyuz spacecraft. MS-25 also saw the launch of two people from Belarus, as the mission commander, Oleg Novitsky was born in Chervyen, when it was part of the Byelorussian Soviet Socialist Republic.

Prime crew

Position	Launching crew member	Landing crew member
Commander	Oleg Novitsky, Roscosmos 21st Visiting Expedition Fourth spaceflight	Oleg Kononenko, Roscosmos Expedition 69/70/71 Fifth spaceflight
Spaceflight Participant/ Flight Engineer	Maryna Vasileuskaya, Belarus Space Agency 21st Visiting Expedition First spaceflight	Nikolai Chub, Roscosmos Expedition 69/70/71 First spaceflight
Flight Engineer	Tracy Caldwell-Dyson, NASA Expedition 70/71 Third spaceflight

Backup crew

Position	Crew
Commander	Ivan Vagner, Roscosmos
Spaceflight participant	Anastasia Lenkova, Belarus Space Agency
Flight Engineer	Donald Pettit, NASA

Flight

Soyuz MS-25 rolled out to Pad 31/6

It was originally scheduled for launch on 21 March 2024, but due to a voltage drop in one of the power generators, the launch was aborted.^[8] The second launch attempt on 23 March 2024 was successful.

Caldwell-Dyson spent approximately six months aboard the International Space Station. Novitsky and Vasileuskaya of Belarus spent approximately 13 days aboard the orbital complex as a part of 21st ISS visiting expedition before returning aboard Soyuz MS-24.^[9]

Undocking and Return

At the end of Expedition 71, Caldwell-Dyson returned to Earth on Soyuz MS-25 with Roscosmos cosmonauts Oleg Kononenko and Nikolai Chub on 23 September 2024. They arrived with NASA astronaut Loral O'Hara on Soyuz MS-24 on 15 September 2023. O'Hara returned to Earth on MS-24 with Novitsky and Vasileuskaya.^[9][10] Kononenko and Chub remained aboard the orbital laboratory for a year. As the mission lasted 374 days, Kononenko spent a total of 1,111 days in space by the time he returned to Earth. He broke the world record of 878 days in space held by Gennady Padalka on February 4, 2024 at 07:30:08 UTC. He later became the first person to stay 900, 1,000, and 1,100 days in space on 25 February 2024, 4 June 2024, and 12 September 2024 respectively.^[11]