Monday, 27 August 2012

The moon, a Tribute to Neil Armstrong

Reading up on Neil Armstrong I feel, I should contribute in honoring him considering that traveling to a hostile environment with no possible rescue. The whole mission to the moon was an extraordinary feet of engineering excellence combined with a heroism to go beyond the confines of the planet and look into the unknown. In order to go to the moon, a spacecraft must first leave the gravity well of the Earth. The only practical way of accomplishing this currently is with a rocket.

Unlike other airborne vehicles such as balloons or jets, a rocket is the only known form of propulsion which can continue to increase its speed at high altitudes in the vacuum outside the Earth's atmosphere. Upon approach of the target moon, a spacecraft will be drawn ever closer to its surface at increasing speeds due to gravity. In order to land intact, a spacecraft must either be ruggedized to withstand a "hard landing" impact of less than about 100 miles per hour (160 km/h) (not possible with human occupants), or it must decelerate enough for a "soft landing" with negligible speed at contact.

The first three attempts by the Americans to perform a successful hard moon landing with a ruggedized seismometer package in 1962 all failed. The Soviets first achieved the milestone of a hard lunar landing with a ruggedized camera in 1966, followed only months later by the first unmanned soft lunar landing by the Americans. The escape velocity of the target moon is roughly equivalent to the speed of a crash landing on its surface, and thus is the total velocity which must be shed from the target moon's gravitational attraction for a soft landing to occur. For Earth's Moon, this figure is 2.38 kilometers per second (1.48 mi/s).
The Soviets succeeded in making the first crash landing on the Moon in 1959.  Crash landings  may occur because of malfunctions in a spacecraft, or they can be deliberately arranged for vehicles which do not have an on board landing rocket. There have been many such moon crashes, often with their flight path controlled to impact at precise locations on the lunar surface. For example, during the Apollo program the S-IVB third stage of the Saturn V moon rocket as well as the spent ascent stage of the lunar module were deliberately crashed on the Moon several times to provide impacts registering as a moonquake on seismometers that had been left on the lunar surface. Such crashes were instrumental in mapping the internal structure of the Moon.
To return to earth, the escape velocity of the moon must be overcome for the spacecraft to escape the gravity well of the moon. Rockets must be used to leave the Moon and return to space. Upon reaching Earth, atmospheric entry techniques are used to absorb the kinetic energy of a returning spacecraft and reduce its speed for safe landing. These functions greatly complicate a moon landing mission and lead to many additional operational considerations. Any moon departure rocket must first be carried to the Moon's surface by a moon landing rocket, increasing the latter's required size.

In the 1950s, tensions mounted between the two ideologically opposed superpowers of the United States and the Soviet Union that had emerged as victors in the conflict. On 4 October 1957, the Soviet Union launched Sputnik 1 as the first artificial satellite to orbit the Earth and so initiated the Space Race. This unexpected event was a source of pride to the Soviets and shock to the Americans, who could now potentially be surprise attacked by nuclear-tipped Soviet rockets in under 30 minutes. Also, the steady beeping of the radio beacon aboard Sputnik 1 as it passed overhead every 96 minutes was widely viewed on both sides as effective propaganda to Third World countries demonstrating the technological superiority of the Soviet political system compared to the American one.

Despite the troubling mistrust between the two super powers, Nasa pulled off a incredible achievement. Much of the experience have been from previous attempts with the unmanned missions. And still early in the developing stages of flying to the moon NASA seemed over confident to try a manned mission. With luck and hope from everyone who was watching at the time, Neil Armstrong stepped down and faced a new world. Even today when future travel to Mars seems to promise a manned mission one day.

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