The distance between the antenna silos and the most distant missile silo was between 1,000 and . These were by far the most complex, extensive and expensive missile launch facilities ever deployed by the USAF. Launching a missile required fueling it in its silo, and then raising the launcher and missile out of the silo on an elevator. Before each launch, the guidance radar, which was periodically calibrated by acquiring a special target at a precisely known range and bearing, had to acquire a radio on the missile (missile guidance set AN/DRW-18, AN/DRW-19, AN/DRW-20, AN/DRW-21, or AN/DRW-22). When the missile was launched, the guidance radar tracked the missile and supplied precise velocity range and azimuth data to the guidance computer, which then generated guidance corrections that were transmitted to the missile. Because of this, the complex could only launch and track one missile at a time, although another could be elevated while the first was being guided.