 First-half crew Promotional Poster | |
| Mission type | Long-duration expedition |
|---|---|
| Operator | NASA /Roscosmos |
| Mission duration | 233 days, 3 hours and 43 minutes |
| Expedition | |
| Space station | International Space Station |
| Began | 19 April 2025 |
| Ended | 9 December 2025 |
| Arrived aboard | |
| Departed aboard | |
| Crew | |
| Crew size | 7–11 |
| Members | |
| EVAs | 3 |
| EVA duration | 18 hours, 47 minutes |
 Expedition 73 mission patch | |
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Expedition 73 was the 73rdlong-duration expedition to theInternational Space Station (ISS). The expedition began with the departure ofSoyuz MS-26 on 19 April 2025 withJAXA astronautTakuya Onishi taking over the ISS command and concluded with the undocking ofSoyuz MS-27 on 9 December 2025.[1] It continued the extensive scientific research conducted aboard the ISS, focusing on various fields, including biology, human physiology, physics, and materials science. The crew members also maintained and upgraded the space station systems.
The expedition commenced with a crew consisting ofNASA astronautsAnne McClain,Nichole Ayers, andJonny Kim,JAXA astronautTakuya Onishi, andRoscosmos cosmonautsKirill Peskov,Sergey Ryzhikov, andAlexey Zubritsky.
The expedition saw three spacewalks. On May 1, 2025, McClain and Ayers performed a 5-hour, 44-minute EVA to install a modification kit on the port side of the station’s truss structure enabling the future installation of its seventhiROSA and relocated an antenna that communicates with approaching and departing commercial crew and cargo spacecraft.
On June 26, 2025, the crew was joined by the staff ofAxiom Mission 4'sCrew DragonGrace: commanderPeggy Whitson of theUnited States, pilotShubhanshu Shukla ofIndia, and mission specialistsSławosz Uznański-Wiśniewski ofPoland andTibor Kapu ofHungary.[2][3] Their mission marked India, Poland, and Hungary's return tocrewed spaceflight for the first time in over 40 years.[4] During their two-week stay aboard the ISS, the astronauts carried out 60 experiments planned by 31 different countries.[3][5]
SpaceX Crew-11 arrived at the ISS on August 2, transporting NASA astronautsZena Cardman andMichael Fincke, JAXA astronautKimiya Yui, and Roscosmos cosmonautOleg Platonov. The mission featured a handover withCrew-10 of six days. Onishi handed over command of the space station to Ryzhikov on August 5. Crew-10 departed with McClain, Ayers, Onishi, and Peskov on August 8.
On October 16, Ryzhikov and Zubritsky performed a 6-hour, 9-minute spacewalk to install the Ekran-M payload onto theNauka module frame, jettisoned some cameras and a mounting platform, cleaned the windows onZvezda service module, and removed a SSK panel and a Biorisk container.
On October 28, Ryzhikov and Zubritsky performed a 6-hour, 54-minute spacewalk to install the final set of payloads onto theNauka module frame the IPI plasma injector into slots two and three, relocate theERA control panel, clean the Nauka science window, and replace a cassette in the Ekran-M payload.
Soyuz MS-28 arrived at theInternational Space Station (ISS) on November 27, 2025, transporting NASA astronautChristopher Williams and Roscosmos cosmonautsSergey Kud-Sverchkov andSergey Mikayev.
On December 1, 2025, following the reberthing ofCygnus NG-23 to theUnity module, all eight ISS docking ports were simultaneously occupied for the first time in the station's operation. Cygnus had been temporarily positioned onCanadarm2 on November 24 to clear the approach corridor for Soyuz MS-28 at theRassvet nadir port. At this time, the station hosted eight visiting vehicles: two SpaceXDragon 2 spacecraft (Crew-11 andCRS-33), the Northrop GrummanCygnus XL freighter (NG-23), the JAXA'sHTV-X cargo ship (HTV-X1), RoscosmosSoyuz MS crew vehicles (MS-27 andMS-28), and twoProgress MS cargo spacecraft (MS-31 andMS-32).[6]
After a handover period, Ryzhikov transferred command of the ISS to Fincke on December 7. The expedition concluded on December 9 with the departure of Ryzhikov, Zubritsky, and Kim aboard Soyuz MS-27.
Events involving crewed spacecraft are listed in bold.
Previous mission:Expedition 72
19 April 2025 -Soyuz MS-26 undocking, official switch fromExpedition 72
22 April 2025 -CRS SpX-32 docking
1 May 2025 - EVA 1 (US-93) McClain/Ayers: 5 hrs, 44 mins
23 May 2025 -CRS SpX-32 undocking
26 June 2025 -Axiom Mission 4 docking (Non-Expedition crew)
1 July 2025 -Progress MS-29 undocking
5 July 2025 -Progress MS-31 docking
14 July 2025 -Axiom Mission 4 undocking (Non-Expedition crew)
2 August 2025 -SpaceX Crew-11 docking
5 August 2025 -ISS Expedition 73 change of command fromTakuya Onishi toSergey Ryzhikov
8 August 2025 -SpaceX Crew-10 undocking
25 August 2025 -CRS SpX-33 docking
9 September 2025 -Progress MS-30 undocking
13 September 2025 -Progress MS-32 docking
18 September 2025 -CRS NG-23 capture and berthing
16 October 2025 - EVA 2 (VKD-64) Ryzhikov/Zubritsky: 6 hrs, 9 mins
28 October 2025 - EVA 3 (VKD-65) Ryzhikov/Zubritsky: 6 hrs, 54 mins
29 October 2025 -HTV-X1 capture and berthing
27 November 2025 -Soyuz MS-28 docking
7 December 2025 -ISS Expedition 73/74 change of command fromSergey Ryzhikov toMichael Fincke
9 December 2025 -Soyuz MS-27 undocking, official switch toExpedition 74
Next mission:Expedition 74
| Flight | Astronaut | Increment 73a | Increment 73b | Increment 73c | Increment 73d |
|---|---|---|---|---|---|
| 19 Apr-2 Aug 2025 | 2-8 Aug 2025 | 8 Aug-27 Nov 2025 | 27 Nov-9 Dec 2025 | ||
| Soyuz MS-27 |  Sergey Ryzhikov,RoscosmosThird spaceflight | Flight engineer | Commander | ||
| Alexey Zubritsky,Roscosmos First spaceflight | Flight engineer | ||||
 Jonny Kim,NASAFirst spaceflight | Flight engineer | ||||
| SpaceX Crew-10 | Anne McClain,NASA Second spaceflight | Flight engineer | Off station | ||
| Nichole Ayers,NASA First spaceflight | Flight engineer | Off station | |||
 Takuya Onishi,JAXASecond spaceflight | Commander | Off station | |||
| Kirill Peskov,Roscosmos First spaceflight | Flight engineer | Off station | |||
| SpaceX Crew-11 | Zena Cardman,NASA First spaceflight | Off station | Flight engineer | ||
| Michael Fincke,NASA Fourth spaceflight | Off station | Flight engineer | |||
| Kimiya Yui,JAXA Second spaceflight | Off station | Flight engineer | |||
| Oleg Platonov,Roscosmos First spaceflight | Off station | Flight engineer | |||
| Soyuz MS-28 | Sergey Kud-Sverchkov,Roscosmos Second spaceflight | Off station | Flight engineer | ||
| Sergey Mikayev,Roscosmos First spaceflight | Off station | Flight engineer | |||
| Christopher Williams,NASA First spaceflight | Off station | Flight engineer | |||
| Vehicle | Purpose | Port | Docking date | Undocking date |
|---|---|---|---|---|
| Vehicles inherited from Expedition 72 | ||||
| Progress MS-29 | Cargo | Poisk zenith | 23 Nov 2024 | 1 Jul 2025 |
| Progress MS-30 | Cargo | Zvezda aft | 1 Mar 2025 | 9 Sep 2025 |
| SpaceX Crew-10"Endurance" | Exp. 72/73 crew | Harmony forward | 16 Mar 2025 | 8 Aug 2025 |
| Soyuz MS-27"Favor" | Exp. 72/73 crew | Prichal nadir | 8 Apr 2025 | 9 Dec 2025 |
| Vehicles docked during Expedition 73 | ||||
| CRS SpX-32 | Cargo | Harmony zenith | 22 Apr 2025 | 23 May 2025 |
| Ax-4"Grace" | Visiting commercial mission | Harmony zenith | 26 Jun 2025 | 14 Jul 2025 |
| Progress MS-31 | Cargo | Poisk zenith | 5 Jul 2025 | 2026 (Exp. 74) |
| SpaceX Crew-11"Endeavour" | Exp. 73/74 crew | Harmony zenith | 2 Aug 2025 | 14 Jan 2026 (Exp. 74) |
| CRS SpX-33 | Cargo | Harmony forward | 25 Aug 2025 | Apr 2026 (Exp. 74) |
| Progress MS-32 | Cargo | Zvezda aft | 13 Sep 2025 | Feb 2026 (Exp. 74) |
| CRS NG-23 | Cargo | Unity nadir | 18 Sep 2025 | March 2026 (Exp. 74) |
| HTV-X1 | Cargo | Harmony nadir | 29 Oct 2025 | 2026 (Exp. 74) |
| Soyuz MS-28"Gyrfalcon" | Exp. 73/74 crew | Rassvet nadir | 27 Nov 2025 | 26 Jul 2026 (Exp. 74) |
| Segment | US Orbital Segment | Russian Orbital Segment | ||||||
|---|---|---|---|---|---|---|---|---|
| Period | Harmony forward | Harmony zenith | Harmony nadir | Unity nadir | Rassvet nadir | Prichal nadir | Poisk zenith | Zvezda aft |
| 19–22 Apr 2025 | SpaceX Crew-10 | Vacant | Vacant | Vacant | Vacant | Soyuz MS-27 | Progress MS-29 | Progress MS-30 |
| 22 Apr–23 May 2025 | CRS SpX-32 | |||||||
| 23 May–26 Jun 2025 | Vacant | |||||||
| 26 Jun–1 Jul 2025 | Ax-4 | |||||||
| 1–5 Jul 2025 | Vacant | |||||||
| 5–14 Jul 2025 | Progress MS-31 | |||||||
| 14 Jul–2 Aug 2025 | Vacant | |||||||
| 2–8 Aug 2025 | SpaceX Crew-11 | |||||||
| 8–25 Aug 2025 | Vacant | |||||||
| 25 Aug–9 Sep 2025 | CRS SpX-33 | |||||||
| 9–13 Sep 2025 | Vacant | |||||||
| 13–18 Sep 2025 | Progress MS-32 | |||||||
| 18 Sep–29 Oct 2025 | CRS NG‑23 | |||||||
| 29 Oct–27 Nov 2025 | HTV-X1 | |||||||
| 27 Nov–9 Dec 2025 | Soyuz MS-28 | |||||||
ThePrichal aft, forward, starboard, and aft ports all have yet to be used since the module originally docked to the station and are not included in the table.
| 2000–2004 |  | |
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| 2005–2009 | ||
| 2010–2014 | ||
| 2015–2019 | ||
| 2020–2024 | ||
| Since 2025 | ||
| Related | ||
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