events
Apollo program: Apollo 8 performs the first successful Trans-Earth injection (TEI) maneuver, sending the crew and spacecraft on a trajectory back to Earth from Lunar orbit.
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Apollo program
1961–1972 American crewed lunar exploration program
The Apollo program, also known as Project Apollo, was the United States human spaceflight program led by NASA, which landed the first humans on the Moon in 1969. Apollo was conceived during Project Mercury and executed after Project Gemini. It was conceived in 1960 as a…Source: Wikipedia (CC BY-SA)
Apollo 8
First crewed space mission to orbit the Moon
Apollo 8 was the first crewed spacecraft to leave Earth's gravitational sphere of influence, and the first human spaceflight to reach the Moon. The crew orbited the Moon ten times without landing and then returned to Earth. The three astronauts—Frank Borman, Jim Lovell, and…Source: Wikipedia (CC BY-SA)
Trans-Earth injection
Space flight maneuver
A trans-Earth injection (TEI) is a propulsion maneuver used to set a spacecraft on a trajectory which will intersect the Earth's sphere of influence, usually putting the spacecraft on a free return trajectory.Source: Wikipedia (CC BY-SA)
Earth
Third planet from the Sun
Earth is the third planet from the Sun and the only astronomical object known to harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is contained in its global ocean, covering…Source: Wikipedia (CC BY-SA)
Lunar orbit
Orbit of an object around the Moon
In astronomy and spaceflight, a lunar orbit is an orbit by an object around Earth's Moon. In general these orbits are not circular. When farthest from the Moon a spacecraft is said to be at apolune, apocynthion, or aposelene. When closest to the Moon it is said to be at…Source: Wikipedia (CC BY-SA)
December 25
Day of the year
December 25 is the 359th day of the year in the Gregorian calendar; six days remain until the end of the year.Source: Wikipedia (CC BY-SA)