text: what were the first space missions?   yuri gagain first visited the space on 12th april 1961.  here is the full information :       [yuri alekseevich gagarin, from the vostok 1, april 12, 1961.]    he was the first man in space. imagine leaving earth before anyone had done it before! nobody could tell what would happen to him, nobody really knew how the brain would function in weightlessness, or how the body would adapt.   on march 9, 1934, a boy was born in the country-side west of moscow. his name was yuri gagarin. he grew up on a collective farm, where his father worked as a carpenter. when yuri was seven years old, the german armies invaded russia. yuris father joined the army, while his mother took him and his older brother and sister away from the fighting.   in high-school, yuri decided to train as a technician, and attended a technical school on the outskirts of moscow. he left school in 1951 as a trained metalworker and enrolled at an industrial college. while he was a student he became interested in aircraft and took lessons at a local flying school. pretty soon, it became obvious that young yuri had a natural talent for flying, and when he graduated from college in 1955, he joined the soviet airforce. it became evident that gagarins abilities as a pilot were beyond normal, and he was taken of normal duties to work as a test-pilot, flying new and experimental aircraft.   soon yuri went to his officers and volunteered to become a cosmonaut. his officers were stunned, since no-one had ever before volunteered for such a mission, and consequently there were no procedures for this. however, gagarins name was passed on to the people in charge of the top-secret soviet space-project, and after a while he was contacted by some representatives who wanted to test him.   yuri gagarin was selected among a special group of the soviet unions 20 best test-pilots. later, due to economical restrictions, this group was limited to six pilots. these went on to further training, while the others returned to test-flying. during the very tough and difficult training-period, yuri obtained top grades from the instructors.   among other things gagarin withstood 13 gs in the centrifuge, and, as a part of the psychological training, sat in a soundless, lightless room for 24 hours. the instructors described him as a man who "...submits useful suggestions at meetings. always sure of his resources... very difficult, if not impossible to upset... stands out among his colleagues thanks to his great scope of active attention, bright mind and quick reaction".   the official announcement of gagarin as pilot was made on april 11, but he was privately informed on april 9.  1961, at the age of 27, gagarin left the earth. it was april the 12th, 9.07 moscow time (launch-site, baikonur). 108 minutes later, he was back . the period of orbital revolution was 89:34 minutes (this figure was "calculated by electronic computers"). the missions maximum flight altitude was 327 000 meters. the maximum speed reached was 28 260 kilometers per hour.   "on the 12th of april, 1961, the soviet spaceship-sputnik was put in orbit around the earth with me on board" "...there was a good view of the earth which had a very distinct and pretty blue halo. it had a smooth transition from pale blue, blue, dark blue, violet and absolutely black. it was a magnificent picture." [gagarin in his official statement after the flight, april 15, 1961.]   the vessel used was the soviet spaceship/satellite vostok 1, which was a small one-manned spherical descent module with a diameter of 2.3 meters. the module was mounted on top of an instrument module containing the engine system. together these weighed less than five tonnes. the cosmonaut was strapped into an ejection seat, from which he would exit the descent module upon re-entry.   the vostok 1 was mounted on a sl-3 variant of the ss-6 sapwood rocket, which was 38.36 meters long and weighed 287.03 tonnes at la