NASA's GLORY mission, to be launched February 23, will carry three CubeSats as hitchhikers. One is Montana State University's Explorer-1[Prime], a mission replicating the experiment carried out by the original Explorer 1 in 1958. The gamma ray detector on board will not be from 1958, but a development item from the Pioneer 10 mission, provided by the late Dr. James Van Allen, who directed the original experiment that found the Van Allen radiation belts. MSU hoped to launch the mission on the 50th anniversary of the original, but even tiny space projects are never as simple to build (and especially to launch) as originally projected.
COMMENT: When I talked to MSU's director for this mission a few years ago, he recounted telling Van Allen that they were going to replicate his 1958 experiment. Van Allen's deadpan response: "Well, I hope you don't prove me wrong."