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. 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, Canada, the European Space Agency and China.
Skylab was the United States' first space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three trios of astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Operations included an orbital workshop, a solar observatory, Earth observation and hundreds of experiments. Skylab's orbit eventually decayed and it disintegrated in the atmosphere on July 11, 1979, scattering debris across the Indian Ocean and Western Australia.
A space station is a spacecraft which remains in orbit and hosts humans for extended periods of time. It therefore is an artificial satellite featuring habitation facilities. The purpose of maintaining a space station varies depending on the program. Most often space stations have been research stations, but they have also served military or commercial uses, such as hosting space tourists.
Human spaceflight programs have been conducted, started, or planned by multiple countries and companies. Until the 21st century, human spaceflight programs were sponsored exclusively by governments, through either the military or civilian space agencies. With the launch of the privately funded SpaceShipOne in 2004, a new category of human spaceflight programs – commercial human spaceflight – arrived. By the end of 2022, three countries and one private company (SpaceX) had successfully launched humans to Earth orbit, and two private companies had launched humans on a suborbital trajectory.
The Skylab Rescue Mission was an unflown rescue mission, planned as a contingency in the event of astronauts being stranded aboard the American Skylab space station. If flown, it would have used a modified Apollo Command Module that could be launched with a crew of two and return a crew of five.
Skylab 4 was the third crewed Skylab mission and placed the third and final crew aboard the first American space station.
A space rendezvous is a set of orbital maneuvers during which two spacecraft, one of which is often a space station, arrive at the same orbit and approach to a very close distance. Rendezvous requires a precise match of the orbital velocities and position vectors of the two spacecraft, allowing them to remain at a constant distance through orbital station-keeping. Rendezvous may or may not be followed by docking or berthing, procedures which bring the spacecraft into physical contact and create a link between them.
Spacecraft call signs are radio call signs used for communication in crewed spaceflight. These are not formalized or regulated to the same degree as other equivalent forms of transportation, like aircraft. The three nations currently launching crewed space missions use different methods to identify the ground and space radio stations; the United States uses either the names given to the space vehicles or else the project name and mission number. Russia traditionally assigns code names as call signs to individual cosmonauts, more in the manner of aviator call signs, rather than to the spacecraft.
A mission patch is a cloth reproduction of a spaceflight mission emblem worn by astronauts and other personnel affiliated with that mission. It is usually executed as an embroidered patch. The term space patch is mostly applied to an emblem designed for a crewed space mission. Traditionally, the patch is worn on the space suit that astronauts and cosmonauts wear when launched into space. Mission patches have been adopted by the crew and personnel of many other space ventures, public and private.
Spaceflight began in the 20th century following theoretical and practical breakthroughs by Konstantin Tsiolkovsky, Robert H. Goddard, and Hermann Oberth, each of whom published works proposing rockets as the means for spaceflight. The first successful large-scale rocket programs were initiated in Nazi Germany by Wernher von Braun. The Soviet Union took the lead in the post-war Space Race, launching the first satellite, the first animal, the first human and the first woman into orbit. The United States landed the first men on the Moon in 1969. Through the late 20th century, France, the United Kingdom, Japan, and China were also working on projects to reach space.
The United States Astronaut Hall of Fame, located inside the Kennedy Space Center Visitor Complex Heroes & Legends building on Merritt Island, Florida, honors American astronauts and features the world's largest collection of their personal memorabilia, focusing on those astronauts who have been inducted into the Hall. Exhibits include Wally Schirra's Sigma 7 space capsule from the fifth crewed Mercury mission and the Gemini IX spacecraft flown by Gene Cernan and Thomas P. Stafford in 1966.
Skylab B was a proposed second US space station similar to Skylab that was planned to be launched by NASA for different purposes, mostly involving the Apollo–Soyuz Test Project, but was canceled due to lack of funding. Two Skylab modules were built in 1970 by McDonnell Douglas for the Skylab program, originally the Apollo Applications Program. The first was launched in 1973 and the other put in storage, while NASA considered how to use the remaining assets from Apollo.
Docking and berthing of spacecraft is the joining of two space vehicles. This connection can be temporary, or partially permanent such as for space station modules.
Soyuz Sever, also spelled Soyuz Siber,, was an early (1959–1962) design of the Soyuz spacecraft. The Soyuz Sever design of a crewed spacecraft started the Soyuz programme. In 1956, the Soyuz Sever spacecraft was proposed as the replacement for the Vostok spacecraft. Vostok spacecraft had only a crew of one; the Soyuz Sever plan would have crew of three. Sever was planned to be launched on a R7 rocket or Vostok rocket. The Sever plans were made by the Experimental Design Bureau (OKB-1) of the Soviet Union. While the Sever spacecraft was never built and launched, many of the designs and testing outcomes became part of the first generation Soyuz spacecraft, Soyuz 7K-OK and the Soyuz 1 mission launched on 23 April 1967. Sever final plan was to take crews to a Sever space station, OS-1962.
