Vanguard 1

Also called grapefruit

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General

Designation	00005 / 58002B
Launch date	17 Mar 1958
Country of origin	United States
Mission	Scientific: high atmosphere study
Perigee/Apogee	656/3866 km
Inclination	34.3°
Period	133.2 min
Launch vehicle	Vanguard #3
Launch site	Cape Canaveral
Mass at launch	1.47 kg

Sphere of 16 cm diameter. Carries a temperature sounder and a radio transmitter.

The world's longest orbiting artificial satellite.

It accomplished:
- First orbiting package to be powered by solar energy.
- Returned a wealth of information on air density, temperature ranges and micrometeorite impact.
- Maintained an orbit so stable that cartographers were able to more accurately redrawn maps of islands in the Pacific Ocean.
- Revealed that the Earth is slightly pear-shaped rather than round.

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