Tuesday, August 7, 2007

Human Spaceflight info.

Human Spaceflight
Within a year after the successes of the first small artificial satellites in 1957 and 1958, both the U.S. and the USSR were developing programs to place people in earth orbit. Both countries sent carefully monitored dogs and primates into orbit to study the effects of weightlessness on living creatures.
Vostok and Mercury Programs
The USSR was the first to put a human into space when cosmonaut Yury A. Gagarin made one orbit of the earth in Vostok 1 on April 12, 1961. During his flight time of 1 hr 48 min he reached an apogee of 327 km (203 mi) and a perigee of 180 km (112 mi). He landed safely in Siberia. In the next two years five more Vostok flights were made. The pilot of Vostok 6 was Valentina V. Tereshkova, the first woman to fly in space. Launched on June 16, 1963, she orbited the earth 48 times.
Meanwhile, a similar U.S. program, called Mercury, was taking shape. On May 5, 1961, Comdr. Alan B. Shepard, Jr., of the U.S. Navy became the first American in space. The Mercury spacecraft, named Freedom 7, flew a ballistic trajectory and made a 15-min suborbital flight. A similar flight followed on July 21, flown by Capt. Virgil I. (Gus) Grissom (1926-67) of the U.S. Air Force. On Feb. 20, 1962, Lt. Col. John H. Glenn, Jr., of the U.S. Marine Corps, became the first U.S. astronaut to orbit the earth, in a flight of three orbits. Three additional Mercury flights were made in 1962 and 1963 by Lt. Col. M. Scott Carpenter (1925- ) of the navy; Comdr. Walter (Wally) M. Schirra, Jr. (1923- ), also of the navy; and Maj. Leroy Gordon Cooper, Jr. (1927-2004) of the air force.
Voskhod and Gemini Programs
The Russian Voskhod was an adaptation of the Vostok spacecraft modified to accommodate two and three cosmonauts. On Oct. 12, 1964, cosmonauts Vladimir M. Komarov (1927-67), Boris B. Yegorov (1937-94), and Konstantin P. Feoktistov (1926- ) made a 15-orbit flight in Voskhod 1. This was the only piloted flight that year and brought the total cumulative man-hours of Soviet cosmonauts in space to 455. The U.S. astronauts had a total then of 54 man-hours in space. On March 18, 1965, cosmonauts Pavel I. Belyayev (1925-70) and Aleksei A. Leonov (1934- ) were launched in Voskhod 2. During this 17-orbit flight, Leonov made the first walk in space, or performed extravehicular activity (EVA), leaving the spacecraft and drifting out on an umbilical tether.
The U.S. Gemini program was designed to develop the technology required to go to the moon. In May 1961 U.S. President John F. Kennedy had instituted the Apollo program, designed to land a man on the moon and return him safely to the earth "before the decade is out." This national commitment resulted in an intensive, large-scale, piloted flight program. The Gemini spacecraft carried two astronauts and was designed to operate for extended periods of time and to develop rendezvous and docking techniques with another orbiting spacecraft. Ten Gemini flights with human passengers were made in 1965-66.
During the Gemini 4 flight Maj. Edward H. White II (1930-67) of the air force became the first U.S. astronaut to perform EVA. Using a pressurized-gas, jet-maneuvering device, he spent 21 min in space. While Gemini 6 and 7 were in orbit together in December 1965, they rendezvoused within a few feet of each other. After orbiting for 20 hr, Gemini 6 with Schirra and Maj. Thomas P. Stafford (1930- ) of the air force landed, and Gemini 7 with Lt. Col. Frank Borman (1928- ) of the air force and Comdr. James A. Lovell, Jr. (1928- ), of the navy went on to spend a total of 334 hr in orbit. This flight of nearly 14 days provided medical data on humans in space that was necessary to assure success of the 10-day Apollo lunar mission. Furthermore, it demonstrated the reliability of systems such as hydrogen-oxygen fuel-cell electric power and reaction controls. On the Gemini 10, 11, and 12 flights, rendezvous and docking were accomplished repeatedly with a target vehicle that had previously been orbited.
By the end of the last Gemini flight in November 1966, U.S. astronauts had accumulated nearly 2000 man-hours in space, which exceeded the Soviet cosmonaut total, and about 12 hr in EVA.
Soyuz and Apollo
The year 1967 was one of tragedy for both space-faring nations. On January 27, during a ground test of the Apollo spacecraft at Cape Kennedy (now Cape Canaveral), fire broke out in the three-man command module (CM). Because of the pressurized pure-oxygen atmosphere inside the spacecraft, a flash fire engulfed and killed the three astronauts - Grissom, White, and Lt. Comdr. Roger B. Chaffee (1935-67) of the navy. As a result of this tragedy, the Apollo program was delayed more than a year for a major review of vehicle design and materials.
On April 23, 1967, cosmonaut Komarov was launched in the first manned flight of a new Soviet spacecraft, Soyuz. The Soyuz had room for three cosmonauts and a separate working compartment, accessible through a hatch, for experiments. Following reentry into the earth's atmosphere and deployment of landing parachutes, the shroud lines became twisted, and Komarov plunged to his death. The Soviet space program was set back nearly two years.
In October 1968 the first manned Apollo flight was launched by a Saturn 1B booster. Astronauts Schirra, Maj. R. Walter Cunningham (1932- ) of the U.S. Marine Reserve Corps, and Maj. Donn F. Eisele (1930-87) of the air force circled the earth for 163 orbits, checking spacecraft performance, photographing the earth, and transmitting television pictures. In December 1968 Apollo 8, a landmark flight carrying astronauts Borman, Lovell, and Maj. William A. Anders (1933- ) of the air force, circled the moon 10 times and returned to earth safely. The Apollo 9 flight, with Maj. James A. McDivitt (1929- ) and Col. David R. Scott (1932- ) of the air force and civilian Russell L. Schweickart (1935- ), checked out undocking, rendezvous, and docking of the Apollo lunar module (LM) landing craft during a 151-orbit mission. The Apollo 10 flight, with astronauts Stafford and Lt. Comdr. John W. Young (1930- ) and Comdr. Eugene A. Cernan (1934- ) of the navy, made 31 orbits of the moon in a rehearsal for the lunar landing. As planned, Stafford and Cernan transferred from the Apollo CM to the LM, separated, and descended to within 16 km (10 mi) of the lunar surface while astronaut Young piloted the CM. Subsequently, rendezvous and docking of the ascent stage of the LM was accomplished; the two astronauts then transferred to the CM, discarded the LM, fired the service module rocket for return trajectory to earth, and returned safely. Project Apollo was now ready to land astronauts on the moon.
Meanwhile, the USSR launched automated Zond spacecraft around the moon, carrying cameras and biological specimens. Col. Georgi T. Beregovoi (1921-95) flew a 60-orbit mission in Soyuz 3 in October 1968. Soyuz 4 and 5 rendezvoused and docked in earth orbit in January 1969. While the spacecraft were linked, cosmonauts Aleksei S. Yeliseyev (1934- ) and Lt. Col. Yevgeny V. Khrunov (1933-2000), in space suits, transferred by EVA from Soyuz 5 to Soyuz 4, which was piloted by Col. Vladimir A. Shatalov (1927- ). In October 1969 Soyuz 6, 7, and 8, each launched a day apart, rendezvoused in orbit but did not dock. Soyuz 9, with a two-cosmonaut crew, set a flight duration record of almost 18 days in June 1970.