Explorer 2Rocket launchby USALaunch time5 Mar 195818:27 UTCfailureFourth stage did not ignite. As a result, Explorer 2 failed to reach orbit.MissionRocketPayloadsRocket Juno Ilaunched from Cape Canaveral, LC-26AUSAPayloadsTotal mass 23 kgNamePurposeMassCommentExplorer 2scientific satellite14.5 kg-