The International Space Station has been continuously inhabited since November 2000. Keeping it running requires a steady flow of astronauts, food, water, spare parts and science experiments. This article explains which spacecraft do this work and how the logistics chain to the station is organised.
How do the crew and supplies get to the ISS?
In short: astronauts travel to the ISS on crew spacecraft such as SpaceX Crew Dragon and the Russian Soyuz, launched on rockets from Florida and Baikonur. Supplies travel on uncrewed cargo spacecraft such as Cargo Dragon, Cygnus and Progress, which dock or are berthed to the station and are unloaded by the crew. The sections below describe each vehicle.
Crew transport
- SpaceX Crew Dragon: under NASA's Commercial Crew Program, Crew Dragon carries astronauts to and from the station on regular rotation missions and also flies private astronaut missions.
- Soyuz: the Russian Soyuz spacecraft continues to fly crews from Baikonur, and seat exchange agreements allow astronauts and cosmonauts to fly on each other's vehicles.
- Boeing Starliner: the second vehicle developed under the Commercial Crew Program, intended to give NASA two independent US crew systems.
Cargo transport
- Cargo Dragon: SpaceX's cargo version can return experiments and hardware to Earth, which makes it valuable for science.
- Cygnus: Northrop Grumman's cargo vehicle delivers supplies and is filled with waste before it burns up during reentry.
- Progress: the Russian cargo spacecraft delivers supplies and propellant and helps raise the station's orbit.
- HTV-X: Japan's new cargo vehicle, the successor to the HTV that flew to the station from 2009 to 2020.
Docking and berthing
Crew vehicles and some cargo vehicles dock autonomously to a docking port. Others approach the station and are captured by the robotic arm Canadarm2 before being berthed to a port. The cover image shows Crew Dragon approaching the station during its first uncrewed test flight in 2019.
Why this matters beyond the ISS
The commercial crew and cargo services developed for the ISS are the foundation for the next generation of commercial space stations. The same vehicles, contracts and operational experience will be used to supply these stations after the ISS is retired.
Current missions in 2026
NASA has named the crew of SpaceX Crew-14, which will launch to the station no earlier than spring 2027, see our Crew-14 article. The next SpaceX cargo flight, CRS-35, is targeted for no earlier than October 2026 and will deliver the final IROSA solar arrays, see our CRS-35 article.
Sources
- NASA: International Space Station
- NASA: Commercial Crew Program
- ESA: International Space Station
- NASA: NASA Shares SpaceX Crew-14 Assignments for Space Station Mission
- NASA: NASA Invites Media to SpaceX's 35th Resupply Launch to Space Station
Cover image: SpaceX Crew Dragon approaching the International Space Station during the Demo-1 mission, March 2019. Credit: NASA (iss058e027349), public domain.