The Explorer 5 mission was the last of the original series of Explorer satellites designed, built and operated by NASA's Jet Propulsion Laboratory. However, the mission was scrubbed when a collission between the rocket's booster and its second stage threw off the launch angle.
The Explorer series, which made history in January 1958 when Explorer 1 became the first U.S. space satellite, consisted of more than fifty satellites launched over a period of about 15 years. In 1960, after the launch of Explorer 5, the Jet Propulsion Laboratory turned the project over to NASA's Goddard Space Flight Center and turned its attention to planetary exploration with its Mariner, Ranger and Surveyor spacecraft projects.
August 24, 1958: Launch of Explorer 5 failed when the rocket's booster collided with its second stage after separation, causing the firing angle of the upper stage to be incorrect.