To meet the same DoD requirement for a heavy space launcher, the Army team at the Army Ballistic Missile Agency (ABMA) under the direction of a team led by Wernher von Braun studied a number of designs that clustered existing missile airframes and optionally added new engines. The design series included the "Super-Titan", "Super-Atlas" and "Super-Jupiter". The later quickly became their focus, as it consisted of technology developed at ABMA, while the Atlas and Titan were Air Force designs suffering from extended development problems. The Super-Jupiter design was based almost entirely on existing equipment, using a cluster of Redstone and Jupiter missiles to form a lower stage powered by a new engine, with an upper stage adapted from the Titan. Their proposal was much simpler and lower-risk than the Air Force proposal, which required the development of a new hydrogen-burning upper stage. Like the Air Force team, ABMA also outlined their vision of a manned lunar mission as Project Horizon, using fifteen of these rockets to build a large vehicle in Earth orbit.