Salyut 7 in the context of "Soyuz T-15"

Extravehicular activity (EVA) is any activity done by an astronaut in outer space outside a spacecraft. In the absence of a breathable Earthlike atmosphere, the astronaut is completely reliant on a space suit for environmental support. EVA includes spacewalks and lunar or planetary surface exploration (commonly known from 1969 to 1972 as moonwalks). In a stand-up EVA (SEVA), an astronaut stands through an open hatch but does not fully leave the spacecraft. EVAs have been conducted by the Soviet Union/Russia, the United States, and China; astronauts from Canada, Japan, the United Arab Emirates, and the European Space Agency have also participated in EVAs conducted by those nations.

On March 18, 1965, Alexei Leonov became the first human to perform a spacewalk, exiting the Voskhod 2 capsule for 12 minutes and 9 seconds. On July 20, 1969, Neil Armstrong became the first human to perform a moonwalk, outside his lunar lander on Apollo 11 for 2 hours and 31 minutes. In 1984, Svetlana Savitskaya became the first woman to perform a spacewalk, conducting EVA outside the Salyut 7 space station for 3 hours and 35 minutes. On the last three Moon missions, astronauts also performed deep-space EVAs on the return to Earth, to retrieve film canisters from the outside of the spacecraft. American Astronauts Pete Conrad, Joseph Kerwin, and Paul Weitz also used EVA in 1973 to repair launch damage to Skylab, the United States' first space station.

The Progress (Russian: Прогресс) is a Russian expendable cargo spacecraft. Originally developed for the Soviet space program and derived from the crewed Soyuz spacecraft, Progress has been instrumental in maintaining long-duration space missions by providing consumables like food, water, and air, as well as maintenance equipment. Since its maiden flight in 1978, Progress has supported various space stations, including Salyut 6, Salyut 7, and Mir, and remains a key resupply vehicle for the International Space Station (ISS).

Each Progress mission delivers thousands of kilograms of supplies in its pressurized module. It also carries water, fuel, and gases to replenish the station's resources and sustain its onboard atmosphere. Beyond resupply duties, a docked Progress can maneuver or reboost the station, countering atmospheric drag and maintaining its operational altitude. When a Progress spacecraft nears the end of its design life, it is loaded with waste, undocked, and deorbited to safely make a destructive reentry in Earth's atmosphere.