Luna programme
The Luna programme, sometimes called Lunik by western media, was a series of robotic spacecraft missions sent to the Moon by the Soviet Union between 1959 and 1976. The programme accomplished many firsts in space exploration, including first flyby of the Moon, first impact of the Moon and [Luna 3|first photos of the far side of the Moon]. Each mission was designed as either an orbiter or lander. They also performed many experiments, studying the Moon's chemical composition, gravity, temperature, and radiation.
Twenty-four spacecraft were formally given the Luna designation, although more were launched. Those that failed to reach orbit were not publicly acknowledged at the time, and not assigned a Luna number. Those that failed in low Earth orbit were usually given Cosmos designations. The estimated cost of the Luna programme in 1964 was US$6–10 billion. The Luna 25 mission also continues the Luna designation, although it is considered to be a part of the Luna-Glob exploration programme. The same applies to other planned missions such as Luna 26, Luna 27 and Luna 28.
Mission types
The name Luna was used to designate a variety of spacecraft designs, to achieve several types of missions: flyby, lunar orbiter, soft lander, and sample return spacecraft. Notable achievements include the first Moon flyby, the first impact, the first photos of the far side, the first soft landing, and the first robotic sample return.Impactors
Impactor spacecraft had the generic designation of Ye-1 and were designed to hit the near side of the Moon. Luna 1 missed its intended impact with the Moon and became the first spacecraft to escape the Earth-Moon system. Luna 2 mission successfully hit the Moon's surface, becoming the first man-made object to reach the Moon. This was Luna's only impact success out of six tries from September 1958 to September 1959.Flybys
A flyby is the simplest lunar spacecraft, requiring neither a propulsion device for slowing, nor a guidance system sensitive enough to hit the Moon. Flyby spacecraft had the generic designations of Ye-2 and Ye-3. Their function was to transmit photographs back to Earth. Luna 3 rounded the Moon later that year, and returned the first photographs of its far side, which can never be seen from Earth. This was Luna's only successful flyby, out of three tries from October 1959 to April 1960.Soft landers
Soft landers require rocket propulsion to slow their speed sufficiently to prevent the craft's destruction. They can continue to transmit pictures from the surface, and possibly dig into the lunar soil or return other information about the lunar environment.Luna program landers had the generic designations of Ye-6 or Ye-6M. Two successful soft landings were achieved out of thirteen attempts from January 1963 to December 1966.
Luna 9 became the first probe to achieve a soft landing on another planetary body in February 1966. It transmitted five black and white stereoscopic circular panoramas, which were the first close-up shots of the lunar surface.
Orbiters
Orbiter spacecraft require less thrust and propellant than landers, but still require enough to achieve lunar orbit insertion. Luna 10 became the first artificial satellite of the Moon. Luna program orbiters had the generic designations of Ye-6LF, Ye-6LS, Ye-6S or Ye-8LS. Luna flew six successful orbiters out of eight attempts from March 1966 to May 1974.Rovers
More sophisticated soft lander craft can deploy wheeled vehicles to explore a wider area of the lunar surface than the immediate landing site. Luna program landers with rovers had the generic designations of Ye-8.The first attempted Lunokhod failed in February 1969. Luna 17 and Luna 21 carried Lunokhod vehicles, which were the first robotic wheeled vehicles to explore the Moon's terrain. Lunokhod 1 travelled in 322 days and returned more than 20,000 television images and 206 high-resolution panoramas. Lunokhod 2 operated for about four months, and covered of terrain, A third Lunokhod was built and intended for launch in 1977, but never flew due to lack of launchers and funding.
Sample return
More complex soft lander craft can robotically scoop up a small amount of lunar material, lift off from the surface, and return the material to Earth. Luna program sample return landers had the generic designations of Ye-8-5 or Ye-8-5M.Luna 16, Luna 20 and Luna 24, returned samples of lunar soil to Earth. A total of of soil sample was returned from the three missions.
Luna 15 flew at the same time as the Apollo 11 mission. Neil Armstrong and Buzz Aldrin had already performed the first crewed lunar landing when Luna 15 began its descent, and the spacecraft crashed into a mountain minutes later.