The man who fought for Lunar Orbit Rendezvous (LOR) and played a critical role in the Apollo missions

Sources:
https://wehackthemoon.com/bios/john-c-houbolt

https://www.nasa.gov/langley/hall-of-honor/john-c-houbolt

https://www.nasa.gov/centers/marshall/history/vonbraun/bio.html

https://history.nasa.gov/SP-4308/ch8.htm

https://en.wikipedia.org/wiki/Lunar_orbit_rendezvous

https://www.space.com/25570-nasa-moon-pioneer-john-houbolt-obituary.html

https://www.npr.org/2019/07/18/739934923/meet-john-houbolt-he-figured-out-how-to-go-to-the-moon-but-few-were-listening

https://www.nasa.gov/content/john-c-houbolt-unsung-hero-of-the-apollo-program-dies-at-age-95

https://www.youtube.com/watch?v=atM5lmX5tPk

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19880069339.pdf