Space rendezvous in the context of "67P/Churyumov–Gerasimenko"

Project Gemini (IPA: /ˈdʒɛmɪni/) was the second United States human spaceflight program to fly. It was conducted after the first American crewed space program, Project Mercury, while the Apollo program was still in early development. Gemini was conceived in 1961 and concluded in 1966. The Gemini spacecraft carried a two-astronaut crew. Ten Gemini crews and 16 individual astronauts flew low Earth orbit (LEO) missions during 1965 and 1966.

Gemini's objective was the development of space travel techniques to support the Apollo mission to land astronauts on the Moon. In doing so, it allowed the United States to catch up and overcome the lead in human spaceflight capability the Soviet Union had obtained in the early years of the Space Race, by demonstrating mission endurance up to just under 14 days, longer than the eight days required for a round trip to the Moon; methods of performing extravehicular activity (EVA) without tiring; and the orbital maneuvers necessary to achieve rendezvous and docking with another spacecraft. This left Apollo free to pursue its prime mission without spending time developing these techniques.

Apollo 9 (March 3–13, 1969) was the third human spaceflight in NASA's Apollo program, which successfully tested systems and procedures critical to landing on the Moon. The three-man crew consisted of Commander James McDivitt, Command Module Pilot David Scott, and Lunar Module Pilot Rusty Schweickart. Flown in low Earth orbit, it was the second crewed Apollo mission that the United States launched via a Saturn V rocket, and was the first flight of the full Apollo spacecraft: the command and service module (CSM) with the Lunar Module (LM).

The mission was flown to qualify the LM for lunar orbit operations in preparation for the first Moon landing by demonstrating its descent and ascent propulsion systems, showing that its crew could fly it independently, then rendezvous and dock with the CSM again, as would be required for the first crewed lunar landing. Other objectives of the flight included firing the LM descent engine to propel the spacecraft stack as a backup mode (as was required on the Apollo 13 mission), and use of the portable life support system backpack outside the LM cabin.

Tiangong-1 (Chinese: 天宫一号; pinyin: Tiāngōng yīhào; lit. 'Heavenly Palace 1" or "Celestial Palace 1') was China's first prototype space station. It orbited Earth from September 2011 to April 2018, serving as both a crewed laboratory and an experimental testbed to demonstrate orbital rendezvous and docking capabilities during its two years of active operational life.

Launched uncrewed aboard a Long March 2F launch vehicle on 29 September 2011, it was the first operational component of the Tiangong program, which launched a larger, modular station into orbit in 2021. Tiangong-1 was initially projected to be deorbited in 2013, to be replaced over the following decade by the larger Tiangong-2 and Tiangong-3 space stations, but it orbited until 2 April 2018.

The Apollo spacecraft was composed of three parts designed to accomplish the American Apollo program's goal of landing astronauts on the Moon by the end of the 1960s and returning them safely to Earth. The expendable (single-use) spacecraft consisted of a combined command and service module (CSM) and an Apollo Lunar Module (LM). Two additional components complemented the spacecraft stack for space vehicle assembly: a spacecraft–LM adapter (SLA) designed to shield the LM from the aerodynamic stress of launch and to connect the CSM to the Saturn launch vehicle and a launch escape system (LES) to carry the crew in the command module safely away from the launch vehicle in the event of a launch emergency.

The design was based on the lunar orbit rendezvous approach: two docked spacecraft were sent to the Moon and went into lunar orbit. While the LM separated and landed, the CSM remained in orbit. After the lunar excursion, the two craft rendezvoused and docked in lunar orbit, and the CSM returned the crew to Earth. The command module was the only part of the space vehicle that returned with the crew to the Earth's surface.

Records and firsts in spaceflight are broadly divided into crewed and uncrewed categories. Records involving animal spaceflight have also been noted in earlier experimental flights, typically to establish the feasibility of sending humans to outer space.

The notion of "firsts" in spaceflight follows a long tradition of firsts in aviation, but is also closely tied to the Space Race. During the 1950s and 1960s, the Soviet Union and the United States competed to be the first countries to accomplish various feats. In 1957, the Soviet Union launched Sputnik 1, the first artificial orbital satellite. In 1961, Soviet Vostok 1 cosmonaut Yuri Gagarin became the first person to enter space and orbit the Earth, and in 1969 American Apollo 11 astronaut Neil Armstrong became the first person to set foot on the Moon. No human has traveled beyond low Earth orbit since 1972, when the Apollo program ended.

Gemini 4 (officially Gemini IV) was the second crewed spaceflight in NASA's Project Gemini, occurring in June 1965. It was the tenth crewed American spaceflight (including two X-15 flights at altitudes exceeding 100 kilometers (62 mi; 54 nmi)). Astronauts James McDivitt and Ed White orbited the Earth 66 times in four days, making it the first US flight to approach the five-day flight of the Soviet Vostok 5. The highlight of the mission was the first space walk by an American, during which White floated free outside the spacecraft, tethered to it, for approximately 23 minutes.

The flight also included the first attempt to make a space rendezvous as McDivitt attempted to maneuver his craft close to the Titan II upper stage which launched it into orbit, but this was not successful.

Gemini 12 (officially Gemini XII) was a 1966 crewed spaceflight in NASA's Project Gemini. It was the 10th and final crewed Gemini flight (Gemini 1 and Gemini 2 were uncrewed missions), the 18th crewed American spaceflight, and the 26th spaceflight of all time, including X-15 flights over 100 kilometers (54 nmi). Commanded by Gemini VII veteran James A. Lovell, the flight featured three periods of extravehicular activity (EVA) by rookie Edwin "Buzz" Aldrin, lasting a total of 5 hours and 30 minutes. It also achieved the fifth rendezvous and fourth docking with an Agena target vehicle.

Gemini XII marked a successful conclusion of the Gemini program, achieving the last of its goals by successfully demonstrating that astronauts can effectively work outside of spacecraft. This was instrumental in paving the way for the Apollo program to achieve its goal of landing a man on the Moon by the end of the 1960s.