What is the origin of the word halo?

Buckminster Fuller, discoverer of C60 (Buckminsterfullerene), is the
creator of the HALO name.

This from Bucky himself:

"In 1951, I designed a free-floating tensegrity ring-bridge to be
installed way out from and around the Earth's equator. Within this
"halo" bridge, the Earth would continue its spinning while the circular
bridge would revolve at its own rate. I foresaw Earthian traffic
vertically ascending to the bridge, revolving and descending at
preferred Earth loci."

So there you have it, the origin of the term, "halo."

-MacKay