Probes to the Moon

While most of the publicity and glory of lunar exploration has been given to the manned Apollo missions, it was the unmanned probes of the early and mid- 1960s that paved the way for these missions. The first four American attempts at launching a lunar probe were unsuccessful and on 12 September 1959 the Soviet Union launched the Luna 2 probe, which impacted 800km (500 miles) north of the visual centre of the moon. It thus became the first man-made body to reach a celestial object. Very soon after Luna 2, the Russians again achieved a space ‘first’ when Luna 3 photographed the invisible face of the moon. After these early days, the pace of lunar probe launches accelerated. The American Ranger series of spacecraft were intended to photograph the lunar surface in advance of the Apollo landings. The first six Ranger missions were failures, but Ranger 7 (launched 28 July 1964) sent back more than 4000 high-resolution photographs before impacting in the Sea of Clouds. Two more later Rangers returned more than 13,000 images between them.

In 1963 the Russians were planning for a lunar soft landing. The first attempts were unsuccessful. Luna 9 finally succeeded in 1966 and the spacecraft returned the historic first pictures from the moon’s surface. The rapid sequence of the Russian lunar launches leading up to Luna 9 was a direct response to its American competitor, the Surveyor spacecraft. Surveyor 1 softlanded on the moon barely four months after Luna 9, returning 11,000 pictures over a six-month period. The Surveyor craft were more sophisticated than the Luna vehicles. Further Surveyor landings examined the surface in regions representative of Apollo landing sites. At the same time as the Surveyor craft were landing on the moon, the Americans were launching Lunar Orbiter spacecraft aimed at returning very high resolution photographs of the lunar surface.

During 1969 while all the American efforts were directed towards the Apollo programme, the Russians were landing more lunar craft in a bold attempt to soft-land and return to earth with lunar soil samples. This ambitious programme failed to pre-empt the Apollo 11 landing, but in 1970 Luna 16 did achieve the goal of returning a sample to earth. The Russians never tried to send men to the moon, concentrating solely on robot explorers. Luna 21 carried a rover vehicle (called Lunokhod) which for four months roamed over 37,000 metres (23 miles) on the surface under command from ground control.