Apollo 15 postal covers incidentThe Apollo 15 postal covers incident, a 1972 NASA scandal, involved the astronauts of Apollo 15, who carried about 400 unauthorized postal covers into space and to the Moon's surface on the Lunar Module Falcon. Some of the envelopes were sold at high prices by West German stamp dealer Hermann Sieger, and are known as "Sieger covers". The crew of Apollo 15—David Scott, Alfred Worden, and James Irwin—agreed to take payments for carrying the covers; though they returned the money, they were reprimanded by NASA.
RetroreflectorA retroreflector (sometimes called a retroflector or cataphote) is a device or surface that reflects radiation (usually light) back to its source with minimum scattering. This works at a wide range of angle of incidence, unlike a planar mirror, which does this only if the mirror is exactly perpendicular to the wave front, having a zero angle of incidence. Being directed, the retroflector's reflection is brighter than that of a diffuse reflector. Corner reflectors and cat's eye reflectors are the most used kinds.
Parking orbitA 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.
Apollo 13 (film)Apollo 13 is a 1995 American space docudrama film directed by Ron Howard and starring Tom Hanks, Kevin Bacon, Bill Paxton, Ed Harris, and Gary Sinise. The screenplay by William Broyles Jr. and Al Reinert dramatizes the aborted 1970 Apollo 13 lunar mission and is an adaptation of the 1994 book Lost Moon: The Perilous Voyage of Apollo 13, by astronaut Jim Lovell and Jeffrey Kluger. The film tells the story of astronauts Lovell, Jack Swigert, and Fred Haise aboard Apollo 13 for America's fifth crewed mission to the Moon, which was intended to be the third to land.
Luna 2Luna 2 (), originally named the Second Soviet Cosmic Rocket and nicknamed Lunik 2 in contemporaneous media, was the sixth of the Soviet Union's Luna programme spacecraft launched to the Moon, E-1 No.7. It was the first spacecraft to reach the surface of the Moon, and the first human-made object to make contact with another celestial body. The spacecraft was launched on 12 September 1959 by the Luna 8K72 s/n I1-7B rocket. It followed a direct path to the Moon.
Chandrayaan-1Chandrayaan-1 (, ) was the first Indian lunar probe under the Chandrayaan programme. It was launched by the Indian Space Research Organisation (ISRO) in October 2008, and operated until August 2009. The mission included a lunar orbiter and an impactor. India launched the spacecraft using a PSLV-XL rocket on 22 October 2008 at 00:52 UTC from Satish Dhawan Space Centre, at Sriharikota, Andhra Pradesh. The mission was a major boost to India's space program, as India researched and developed indigenous technology to explore the Moon.
