NASA engineer John Houbolt, as seen in 1962, shows on a blackboard his Lunar Orbit Rendezvous (LOR) concept for landing on the moon.
(Image: © NASA)

In 1961 on this date, Wehrner von Braun officially recommends Lunar Orbit Rendezvous as the most likely way to successfully land on the Moon. This idea, first suggested by John Houboult, an aerospace engineer, was originally met with suspicion and resistance from all corners; however, NASA eventually acknowledged his contribution by awarding him the Exceptional Scientific Achievement Medal in 1963.

You can read an excellent article about John Houboult published just after his death here.