The United States continued missions to the ISS and other goals with the high-cost shuttle system, which was retired in 2011. The Soviet space program was the rocketry and space exploration program conducted by the Soviet Union from the 1930s till its collapse in 1991. The Sputnik 1 became the first artificial Earth satellite on 4 October 1957. The satellite transmitted a radio signal, but had no sensors otherwise. Studying the Sputnik 1 allowed scientists to calculate the drag from the upper atmosphere by measuring position and speed of the satellite. Sputnik 1 broadcast for 21 days until its batteries depleted on 4 October 1957, and the satellite finally fell from orbit on 4 January 1958. The Luna programme was a series of uncrewed robotic satellite launches with the goal of studying the Moon.The program ran from 1959 to 1976 and consisted of 15 successful missions, the program achieved many first achievements and collected data on the Moon's chemical composition, gravity, temperature, and radiation. Luna 2 became the first man made object to make contact with the Moons surface in September 1959. Luna 3 returned the first photographs of the far side of the moon in October 1959. The Vostok Programme the first Soviet spaceflight project to put the Soviet citizens into low Earth orbit and return them safely. The programme carried out six crewed spaceflights between 1961 and 1963. The program was the first program to put humans into space, with Yuri Gagarin becoming the first man in space on April 12, 1961 aboard the Vostok 1. Gherman Titov Became the first person to stay in orbit for a full day on August 7, 1961 aboard the vostok 2. Valentina Tereshkova became the first woman in space on June 16, 1963 aboard the Vostok 6. The Voskhod programme began in 1964 and consisted of two crewed flights before the program was canceled by the Soyuz programme in 1966. Voskhod 1 launched on October 12, 1964 and was the first crewed spaceflight with a multi-crewed vehicle. Alexei Leonov performed the first spacewalk aboard Voskhod 2 on March 18, 1965. The Salyut programme was the first space station program undertaken by the Soviet Union. The goal was to carry out long-term research into the problems of living in space and a variety of astronomical, biological and Earth-resources experiments. The program ran from 1971 to 1986. Salyut 1, the first station in the program, became the world's first crewed space station.