atlasii

Despite the banner in the background, this photo has little (if anything) to do with Atlas. The rocket in the foreground and the ones on the right side of the image are (probably) "ordinary" Centaur stages destined to be used with Titan III or Atlas. But there's no Atlas in the picture. What IS noteworthy are the three tanks in the upper center and left. These look like the Centaur stage that was designed to fit in the Space Shuttle's cargo bay - they never flew, as the Shuttle Centaur program was cancelled a few months after the Challenger disaster. A good account of the Shuttle Centaur program can be found online; search for "Long-forgotten Shuttle/Centaur boosted Cleveland's NASA center" by John Mangels.

See: www.cleveland.com/science/index.ssf/2011/12/long-forgotte...

The 3 Centaur stages at the bottom are for the Titan 4 version. The centaur stage TC 13 are a modified version of Centaur G-Prime for the Titan IV. 16 were produced (TC-8 through TC-23).

That's more likely an Atlas-E with solid upper stage. The one with DMSP-5D2 F11 (Atlas-53E) is the 500th Atlas launched.