John Houbolt, American engineer and academic (b. 1919)
John Cornelius Houbolt (April 10, 1919 – April 15, 2014) was an aerospace engineer credited with leading the team behind the lunar orbit rendezvous (LOR) mission mode, a concept that was used to successfully land humans on the Moon and return them to Earth. This flight path was chosen for the Apollo program in July 1962. The critical decision to use LOR was viewed as vital to ensuring that man reached the Moon by the end of the decade as proposed by President John F. Kennedy. In the process, LOR saved time and billions of dollars by efficiently using the rocket and spacecraft technologies.