Vanguard 2

• abstract: Vanguard 2 or Vanguard II is an earth-orbiting satellite launched February 17, 1959 aboard a Vanguard SLV 4 rocket as part of the United States Navy's Project Vanguard. The satellite was designed to measure cloud-cover distribution over the daylight portion of its orbit, for a period of 19 days, and to provide information on the density of the atmosphere for the lifetime of its orbit (~300 years).

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