The capsule had an escape mechanism for problems prior to launch, and a soft-landing and ejection system during the recovery. The spacecraft was spherical, just like the Sputnik design, and Korolev explained his reasoning for this by saying "the spherical shape would be more stable dynamically". Beginning with work on the Vostok, Konstantin Feoktistov was recruited directly by Korolev to be the principal designer for crewed spaceflight vehicles. On 15 May 1960 an uncrewed prototype performed 64 orbits of the Earth, but the reentry maneuver failed. On 28 July 1960, two dogs by the names of Chaika and Lishichka were launched into space, but the mission was unsuccessful when an explosion killed the dogs. However, on 19 August, the Soviet Union became the first to successfully recover living creatures back to Earth. The dogs, Belka and Strelka were successfully launched into space on a Vostok spacecraft and they completed eighteen orbits. Following this, the Soviet Union sent a total of six dogs into space, two in pairs, and two paired with a dummy. Unfortunately, not all the missions were successful. After gaining approval from the government, a modified version of Korolev's R-7 was used to launch Yuri Alexeevich Gagarin into orbit on 12 April 1961, which was before the United States was able to put Alan Shepard into space. Korolev served as capsule coordinator, and was able to speak to Gagarin who was inside the capsule. The first human in space and Earth orbit returned to Earth via a parachute after ejecting at an altitude of . Gagarin was followed by additional Vostok flights, culminating with 81 orbits completed by Vostok 5 and the launch of Valentina Tereshkova as the first woman cosmonaut in space aboard Vostok 6. Korolev proposed communications satellites and a modified Vostok useful for photographic reconnaissance to quiet Soviet military objections about the cost of planetary and crewed programs of no perceived value for national defense. Korolev planned to move forward with Soyuz craft able to dock with other craft in orbit and exchange crews. He was directed by Khrushchev to cheaply produce more 'firsts' for the piloted program, including a multi-crewed flight. Korolev was reported to have resisted the idea as the Vostok was a one-man spacecraft and the three-man Soyuz was several years away from being able to fly. Khrushchev was not interested in technical excuses and let it be known that if Korolev could not do it, he would give the work to his rival, Vladimir Chelomei.