Explorer I, the first US satellite, is launched by the Army at Cape Canaveral, Fla. The satellite, launched on a Jupiter-C rocket, will later play a key role in the discovery of the Van Allen radiation belt.
Navy Adm. Samuel J. Paparo Jr. assumed leadership of the U.S. Indo-Pacific Command, succeeding Navy Adm. John Aquilino at a change of command ceremony, urging action amid China's “increasing intrusive and expansionist claims,” on May 3