ISS Visiting Vehicles—Past, Present and Future

NASA’s space shuttles Discovery, Atlantis and Endeavour made a combined 37 visits to the ISS between December 1998 and July 2011.

Russian Progress spacecraft have been used for 75 missions to the ISS, with three cargo missions lost due to launch accidents. Russian Proton rockets flew twice, both successfully, to deliver ISS modules.

Russia’s venerable Soyuz capsules have delivered crew to the ISS 62 times since the Expedition 1 crew’s arrival on Nov. 2, 2000, beginning an unbroken string of 20 years of continuous human presence in low Earth orbit.

The European Space Agency launched five Automated Transfer Vehicles to the ISS from 2008 to 2014. The spacecraft has been modified for use as the Service Module for NASA’s Orion deep-space crewed vehicle.

The Japan Aerospace Exploration Agency’s H-II Transfer Vehicle (HTV) flew nine missions to the ISS from 2009 to 2020. The new HTV-X is expected to debut in 2022.

Under a new commercial development and services contract, SpaceX began flying cargo missions to the ISS in 2012. After a flight test and 20 resupply missions—all but one successful—the reusable Cargo Dragon capsules were retired in April 2020. The new Dragon 2 capsule, a variant of the Crew Dragon capsule designed to fly astronauts, is expected to debut in November.

Northrop Grumman, which acquired the Cygnus cargo line when it purchased Orbital ATK, has flown 15 missions to the ISS, all but one successfully. It remains one of three companies holding NASA cargo resupply service contracts.

Following a successful May 30-Aug. 2 SpaceX Demo-2 flight test to the ISS, SpaceX is poised to begin crew rotation missions in November.

Boeing’s CST-100 Starliner is being prepared for a January 2021 uncrewed flight test to the ISS. The company’s Crew Flight Test orbital demonstration is expected in June.

Sierra Nevada Corp.’s winged reusable Dream Chaser space plane is expected to join the ISS cargo fleet in 2021-22.