Concept
Apollo program
Related concepts (38)
Soviet crewed lunar programs
The Soviet crewed lunar programs were a series of programs pursued by the Soviet Union to land humans on the Moon, in competition with the United States Apollo program. The Soviet government publicly denied participating in such a competition, but secretly pursued two programs in the 1960s: crewed lunar flyby missions using Soyuz 7K-L1 (Zond) spacecraft launched with the Proton-K rocket, and a crewed lunar landing using Soyuz 7K-LOK and LK spacecraft launched with the N1 rocket.
Circumlunar trajectory
In orbital mechanics, a circumlunar trajectory, trans-lunar trajectory or lunar free return is a type of free return trajectory which takes a spacecraft from Earth, around the far side of the Moon, and back to Earth using only gravity once the initial trajectory is set. The first spacecraft to fly a circumlunar trajectory was Luna 3. Circumlunar trajectories were also used by Apollo missions prior to lunar orbit insertion, to provide a free return to Earth in the event of a propulsion system malfunction on the way to the Moon.
Lunar soil
Lunar soil is the fine fraction of lunar regolith found on the surface of the Moon and contributes to the Moon's tenuous atmosphere. Lunar soil differs in its origin and properties significantly from terrestrial soil. As the Moon's fine surface layer, lunar soil is picked up by even weak natural phenomena active at the Moon's surface, allowing it to be part of the Moon's scant atmosphere, increasing its even from the surface faint visiblity. Furthermore it is also easily lifted by human activity.
Pogo oscillation
Pogo oscillation is a self-excited vibration in liquid-propellant rocket engines caused by combustion instability. The unstable combustion results in variations of engine thrust, causing variations of acceleration on the vehicle's flexible structure, which in turn cause variations in propellant pressure and flow rate, closing the self-excitation cycle. The name is a metaphor comparing the longitudinal vibration to the bouncing of a pogo stick. Pogo oscillation places stress on the frame of the vehicle, which in severe cases can be dangerous.
Micrometeorite
A micrometeorite is a micrometeoroid that has survived entry through the Earth's atmosphere. Usually found on Earth's surface, micrometeorites differ from meteorites in that they are smaller in size, more abundant, and different in composition. The IAU officially defines meteorites as 30 micrometers to 1 meter; micrometeorites are the small end of the range (~submillimeter). They are a subset of cosmic dust, which also includes the smaller interplanetary dust particles (IDPs).
Parking orbit
A parking orbit is a temporary orbit used during the launch of a spacecraft. A launch vehicle boosts into the parking orbit, then coasts for a while, then fires again to enter the final desired trajectory. The alternative to a parking orbit is direct injection, where the rocket fires continuously (except during staging) until its fuel is exhausted, ending with the payload on the final trajectory. The technology was first used by the Soviet Venera 1 mission to Venus. Geostationary spacecraft require an orbit in the plane of the equator.
Zond 5
Zond 5 (Зонд 5) was a spacecraft of the Soviet Zond program. In September 1968 it became the first spaceship to travel to and circle the Moon in a circumlunar trajectory, the first Moon mission to include animals, and the first to return safely to Earth. Zond 5 carried the first terrestrial organisms to the vicinity of the Moon, including two tortoises, fruit fly eggs, and plants. The Russian tortoises underwent biological changes during the flight, but it was concluded that the changes were primarily due to starvation and that they were little affected by space travel.
Operations and Checkout Building
The Neil Armstrong Operations and Checkout Building (O&C) (previously known as the Manned Spacecraft Operations Building) is a historic building on Merritt Island, Florida, United States. The five-story structure is in the Industrial Area of NASA's Kennedy Space Center. Its has twin-block facilities that include the crew quarter dormitories for astronauts, suit-up preparations prior to their flights, and the other is a large spacecraft workshop used for manufacturing and checking activities on crewed spacecraft.