By IANS
Washington : Vanguard I, the oldest satellite still orbiting the earth, will complete 50 years in space Monday. It was launched March 17, 1958 from Cape Canaveral, Florida.
Vanguard-I, the first ever solar-powered space vehicle, is only six inches across and weighs about 1.5 kg. Its small size, compared to the Soviet Union’s 200-pound Sputnik-I, caused then-Soviet Premier Nikita Khrushchev to dub it “the grapefruit satellite”.
Since its launch 50 years ago, the tiny satellite has gone 196,990 times around the earth and travelled 5.7 billion nautical miles, the distance from earth to beyond the planet Pluto and halfway back. It has provided a wealth of information on the size and shape of the earth, and set a number of space records as well.
Vanguard-I was launched as part of US participation in International Geophysical Year (IGY) (July 1957 to December 1958) in a tri-service project with the US Army operating the tracking stations and the US Air Force providing the launching site.
As part of the scientific programme for the IGY, the Naval Research Laboratory (NRL) was told to place an artificial satellite with a scientific experiment into orbit around the earth.
NRL developed the launch vehicles, developed and installed the satellite tracking system and designed, constructed and tested the satellites in a programme headed by John Hagen.
NRL’s proposal to conduct Project Vanguard was based on experience gained from extensive use of German V-2 and Viking rockets to probe the earth’s upper atmosphere.
The successes of Vanguard-I set the pattern for a multitude of other space ventures in the US and abroad. Vanguard also served as a springboard for NRL scientists to launch several series of space probes to study various aspects of radiation phenomena.
Vanguard I introduced much of the technology that has been applied in other US satellite programmes. For example, it proved that solar cells could be used for several years to power radio transmitters.
Vanguard’s solar cells operated for about seven years, while conventional batteries used to power another onboard transmitter lasted only 20 days. Now the oldest man-made satellite in orbit, Vanguard-I has been 100 percent successful in meeting its scientific objectives.