This week’s image is another from the U.S. Air Force Space & Missile Museum at the Cape Canaveral Air Force Station — it’s a Thor-Able launch vehicle:
Thor-Able got its rather… unusual… look from the fact that it was cobbled together from two existing launch vehicles. The first stage was a modified Thor IRBM, while its second (“Able”) stage was a Vanguard-derivative. As you see it here, the Thor-Able was originally developed to support the Atlas ICBM program — logging nine flights as a sounding rocket in order to test potential warhead designs and materials for the ICBM. But as its kinks got worked out, the vehicle came into service for launching small satellites.
The Thor-Able was used for 16 launches between 1958 and 1960, of which 10 were fully successful (and to be fair, three of the failures resulted from problems with a sometimes-used third stage). Ultimately, Thor-Able launched four spacecraft on at least partially-successful missions:
In the big-picture view, though, possibly the Thor-Able’s most significant role was as a stepping stone on the way to today’s Delta launch vehicle family.