The first launch attempt of the Thor-Delta missile/rocket family was a Thor DM-18 on January 26, 1957, over 67 years ago. The first successful launch attempt was a Thor DM-18 on September 20, 1957.
The first Thor DM-19 launch attempt with a Delta upper stage (Delta later supplanting Thor as the name of the orbital launch variant) came on May 13, 1960. The first successful launch attempt of a Thor DM-19 with a Delta upper stage came on August 20, 1960.
The final Delta IV heavy will launch the NROL-70 mission to geostationary orbit.
The launch will go from SLC-37B at CCSFS.
