Bambi was an extension of the Midas system, cancelled at the same time. It was to have been an orbiting swarm of interceptors or space mines with nuclear warheads, capable of not only detecting ballistic missile launchings but also intercepting the enemy vehicle during boost phase while it was still rising through the atmosphere. This was seen as a very much simpler task than that attempted by the continued Nike Zeus, which had to intercept a reentry vehicle travelling at hypersonic speed, with a very low radar cross-section, and accompanied by jamming and decoys. However the operational deployment and operation of Bambi was seen to be enormous - at least $50 billion a year. Furthermore, the orbiting of hundreds of nuclear weapons involved enormous political, legal and moral issues. Four years later the US signed the UN Space Treaty, prohibiting the orbiting of nuclear weapons. However a conventional version of Bambi was resurrected in the 1980's as Brilliant Pebbles.