NASA had two C-121Gs operating into and out Australia in the late 60s and early 70s in support of the Apollo moon missions. They were originally leased to NASA in 1963 as NASA 420 and NASA 421. In June 1969 they were re-registered N420NA and N421NA respectively. I didn't keep records in those days but as near as I can work out from records of NASA flights and a time I recall being in Sydney, this had to be late November 1972. The record showed it to have arrived in Sydney November 25th and departed December 1st.

Became NASA 421 and then N421NA. Used to support US space program.

Became N421NA