Explorer 43, also called as IMP-I and IMP-6, was a NASA satellite launched as part of Explorer program. Explorer 43 was launched on 13 March 1971 from Cape Canaveral Air Force Station (CCAFS) (restored to its old name of Cape Canaveral in 1974), with a Thor-Delta M6 launch vehicle. Explorer 43 was the sixth satellite of the Interplanetary Monitoring Platform.