John Glenn - astronomy.

John Glenn - astronomy. John Glenn, born in 1921, United States senator and astronaut. Glenn was the first American to orbit the earth, aboard the third piloted flight of the Mercury program. He also became the oldest person ever to go into space when he rode aboard the space shuttle Discovery in late 1998. Glenn was born in Cambridge, Ohio. In 1939 he entered Muskingum College, in Ohio, but he left in his junior year to take preflight training in the Naval Aviation Cadet Program. As a pilot in the U.S. Marine Corps, he flew 149 combat missions in World War II (1939-1945) and the Korean War (1950-1953). In 1957 Glenn became the first person to make a nonstop supersonic (greater than the speed of sound) flight across the United States, setting a speed record of 3 hours 23 minutes 8.4 seconds on a trip from Los Angeles, California, to New York City. In 1958 Glenn joined the group of U.S. military men competing for selection to become the first U.S. astronauts. The National Aeronautics and Space Administration (NASA) chose the first group of astronauts, including Glenn, in 1959. He was selected to fly aboard the third U.S. piloted spaceflight, which was the first piloted U.S. mission to orbit the earth. He and the other six Mercury astronauts trained intensively before their flights. On February 20, 1962, Glenn became the first American to orbit the earth in space, in the Mercury capsule Friendship 7. The three-orbit flight covered about 130,000 km (about 81,000 mi) in 4 hours 55 minutes. At the end of the first orbit, the automatic control system of the Friendship 7 capsule began to malfunction. NASA engineers had planned to let Glenn take over control of the capsule during short test periods, but the malfunction forced Glenn to pilot the capsule manually during the second and third orbits and during reentry. The manual control system functioned flawlessly, so Glenn was able to continue with the flight. He took photographs from the capsule's window, performed simple exercises and movements to test his body's reaction to weightlessness, and made some astronomical observations. During Glenn's second orbit, controllers on the ground discovered that the capsule's heat shield, vital for reentry, had somehow come loose. The straps that held the rocket to the capsule were the only things holding the heat shield to the capsule. Engineers developed a plan to have Glenn keep the rocket attached to the capsule during reentry (normally the rocket would be jettisoned) and steer the capsule so that the pressure of the atmosphere against the capsule would hold the heat shield in place during the descent. Glenn's reentry was the most difficult and stressful part of the mission, but the engineers' plan worked, and Friendship 7 landed safely with a parachute in the Atlantic Ocean. Glenn returned to the earth a national hero. His character and charm made him one of the most popular Mercury astronauts and made NASA reluctant to risk his life by sending him back into space. Frustrated by the government's refusal to allow him to fly in space again, Glenn retired from NASA and the Marine Corps in 1965. His many military and space program awards and honors include the Distinguished Flying Cross, which he was awarded five times, and the Air Medal with 18 clusters. When Glenn retired, he became a business executive and a consultant to NASA. In 1974 Glenn was elected to the U.S. Senate as a Democrat from Ohio. He served four terms before deciding not to seek reelection in 1998. Glenn unsuccessfully contended for the 1984 Democratic presidential nomination. While in Congress, he served on the Special Intelligence Committee. He was ranking member of the Governmental Affairs Committee. Glenn, a military veteran, also served on the Armed Services Committee from 1985 to 1998. Throughout his political career, Glenn lobbied NASA to allow him to go back into space. In October 1998 at the age of 77, Glenn finally returned to space aboard the space shuttle Discovery. This space shuttle mission included a study of the effects of space travel on aging humans. Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.