GATV

Gemini Agena Target Vehicle (GATV) was an uncrewed spacecraft based on the Agena D and launched on an Atlas-SLV3. It was used during the Gemini program to develop and practice orbital space rendezvous and docking techniques in preparation for the Apollo programme. When the ATV for Gemini 6 failed on launch, NASA developed the smaller Augmented Target Docking Adapter (ATDA), fitted with an attitude control propulsion system. The N-00K Nuclear Experiment Package is attached to the side of the equipment rack beneath the single monoprop tank.