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| | Project Vanguard - Wikipedia, the free encyclopedia |
 | | The 1.4 kg spherical Vanguard satellites (designated "Test Vehicles" prior to launch) were built at the NRL, and contained as their payload seven mercury cell batteries in a hermetically sealed container, two tracking radio transmitters, a temperature sensitive crystal, and six clusters of solar cells on the surface of the sphere. |
 | | On October 4, 1957, the Vanguard team learned of the launch of Sputnik I by the USSR while still working on a test vehicle (TV-2) designed to test the first stage of their launcher rocket. |
 | | Vanguard met 100 percent of its scientific objectives, providing a wealth of information on the size and shape of the Earth, air density, temperature ranges, and micrometeorite impact. |
| en.wikipedia.org /wiki/Project_Vanguard (1264 words) |
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