Vostok Program - astronomy.

Vostok Program - astronomy. I INTRODUCTION Vostok Program, series of piloted spacecraft launched in the early 1960s by the Union of Soviet Socialist Republics(USSR). The program (vostok is Russian for "east") grew from the dreams of Sergey Korolyev, the founder of the Soviet space program and the head of the country's leading aerospace design bureau, and from the Cold War space race between the United States and the USSR. A Vostok spacecraft was the first to carry a human into space. See Space Exploration. The space race began in 1957 with the launch of the first satellite, Sputnik 1, by the USSR (see Sputnik). The world reacted so strongly to the launch that Soviet leaders, including Nikita Khrushchev, saw opportunities to win Cold War political battles by making history in space. Later that year Korolyev launched a dog into space aboard Sputnik 2. United States leaders suspected that the Soviets were preparing to launch piloted spacecraft, so the United States established its first manned space program, the Mercury program, in 1958. This move drove the Soviets to accelerate their plans for piloted spacecraft. The USSR rushed to design a spacecraft for piloted flights. They chose to modify a spy satellite (see Satellite, Artificial) to serve as the basis of the Vostok program. The USSR tested the Vostok spacecraft under the name Korabl-Sputnik and launched six piloted Vostok flights. All were successful. The Vostok program's goals were mostly political, but its technical and scientific aims included testing basic spacecraft systems, such as heat shields and life support; showing that humans could survive launch into space, reentry to Earth's atmosphere, and landing; and showing that humans could withstand weightlessness for several days. II SPACECRAFT The USSR hid Vostok's design from the rest of the world until 1965 because of the spacecraft's origin as a spy satellite. The satellites, called Kosmos, used cameras to photograph military movements and installations around the world. When the satellite used up its film, the capsule containing the cameras and film would fall back to Earth. Shielding protected the capsule from burning up in Earth's atmosphere and the film could be recovered and developed. Hundreds of these Kosmos satellites were in operation from the 1960s to the 1990s. Vostok had two basic parts: the capsule and the equipment module. The capsule was the part of Vostok based on Kosmos spy satellites. It was a 2500-kg (5500-lb) sphere made of an aluminum alloy, and it had a diameter of 2.3 m (7.5 ft). A round hatch enabled cosmonauts to enter and exit, and another round hatch opposite it covered the parachute compartment. Four metal straps and a bundle of power and control cables joined the capsule to the equipment module, which was shaped like two blunt cones joined at their bases. Green spherical oxygen tanks ringed Vostok where the capsule joined the equipment module's top cone. The bottom cone held the craft's retrorocket and was covered with metal plates that radiated heat. Vostok had U-shaped communication antennas on its capsule and U-shaped telemetry antennas on its equipment module. These were essential parts of its control system, because Vostok flights were almost completely controlled by automatic systems and controllers on Earth. Compared to the Mercury astronauts, the Vostok cosmonauts were more passengers than pilots. This was in part because Soviet doctors feared that space flight might incapacitate humans. The cosmonauts could override the automatic orientation system (called Vzor) by typing in a code, but they were not given the code before the flight. The code was kept in an envelope on the capsule wall in case the cosmonaut needed it. The Vostok spacecraft fired its retrorocket to drop out of orbit. The capsule's weight distribution kept the heat shield pointed into the atmosphere. The equipment module had no heat shield, so when it detached and fell toward Earth, it burned up in the atmosphere. When the capsule reached the lower atmosphere, a small parachute opened to slow it down. The capsule landed hard, so in the test Korabl-Sputnik missions, the passenger dogs ejected in a cylindrical compartment that had its own parachute. For Vostok flights, the cosmonaut ejected about 4 km (about 2 mi) above the ground in an ejection seat, separated from the seat, and floated gently to the earth with a parachute. III MISSIONS Vostok capsules were the first spacecraft to carry humans into space. The USSR tested the design of the Vostok capsule on flights with dogs, mannequins, and scientific instruments as passengers. All of the piloted Vostok missions were successful, helping the USSR win a major battle in the space race. A Unpiloted Missions Korolyev's engineers tested the Vostok capsule under the Korabl-Sputnik program. On May 15, 1960, Korabl-Sputnik 1 reached orbit. All went as planned until just before the retrorocket fired, when controllers discovered that the spacecraft was pointed away from Earth. When it fired its retrorocket it climbed to a higher orbit instead of heading toward Earth. The spacecraft dropped out of orbit naturally and burned up in 1965. Korabl-Sputnik 2 was launched on August 19, 1960, and was a successful flight by two dogs, Belka and Strelka. By contrast, Korabl-Sputnik 3--launched on December 1, 1960--was intentionally destroyed after its retrorocket shut down prematurely. The capsule probably would have landed safely, but it would have missed the USSR and landed in foreign territory. The dogs onboard, Pchelka and Mushka, were killed. Korabl-Sputnik 4, launched on March 9, 1961, was the first Vostok capsule designed exactly as it would be for piloted flight. Chernushka, the dog aboard, landed safely after one orbit. On Korabl-Sputnik 5, launched on March 25, 1961, a dog named Zvezdochka rode in the capsule as it landed, while a mannequin wearing the Vostok program's Sokol pressure suit ejected before landing. Zvezdochka survived the landing and the Sokol suit performed well. B Piloted Missions On April 12, 1961, with a shout of 'Poyekhali!' ("Let's go!") 27-year-old Yuri Gagarin lifted off from the USSR for a 108-minute, one-orbit flight aboard Vostok 1. All went well during this first piloted spaceflight until the equipment module ejected. By some accounts, the cable bundle linking the module to the capsule failed to detach, causing the two parts of Vostok 1 to tumble wildly about each other. After about 10 minutes they separated, and Gagarin landed safely. Vostok 2, lasting from August 6 to August 7, 1961, was a 24.3-hour flight by 25-year-old cosmonaut Gherman Titov. During his 17 orbits, Titov became the first human to eat, sleep, and experience sickness while in orbit (see Aerospace Medicine: Space Medicine). Vostok 3 was postponed for a year because Soviet doctors wished to study the physiological effects of spaceflight. Andrian Nikolayev made a 64-orbit flight aboard Vostok 3 from August 11 to August 15, 1962. Vostok 4 was launched on August 12, 1962, while Vostok 3 was still in orbit. The Vostok capsules could not maneuver, but Soviet controllers launched Vostok 4 so that it passed within 6.5 km (4.0 mi) of Vostok 3. Vostok 4 carried cosmonaut Pavel Popovich and landed safely on August 15, 1962. At almost five days in duration, Vostok 5 remains the longest solo space mission ever. Valeri Bykovskii flew alone for 81 orbits and 3 million km (2 million mi) from June 14 to June 19, 1963. Valentina Tereshkova became the first woman in space when she flew aboard Vostok 6 from June 16 to June 19, 1963. On its first orbit, Vostok 6 passed within 5 km (3 mi) of Vostok 5. Tereshkova flew on for 2 days 22 hours, covering 1.9 million km (1.2 million mi) in 48 orbits. Soviet engineers planned a Vostok 7 flight that would last a week, but this was canceled so they could concentrate on the Vostok's successor, the Voskhod spacecraft (see Voskhod Program). Contributed By: David S. F. Portree Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.