Slowly but Surely

Air Force space officials announced last week that they have entered the third phase of a four-stage process to position the first Advanced Extremely High Frequency military communications satellite into its intended operational orbit. The satellite experienced an anomaly with one of its propulsion systems upon reaching space in August, forcing USAF to devise an alternate plan to maneuver the spacecraft. Stage three began on Oct. 20 with the firing of two high-efficiency hall current thrusters, or HCTs, for about nine hours as the satellite reached its apogee altitude. These apogee firings will continue every orbit over the next seven to nine months. Stage four will require the near-continuous firing of the HCTs to adjust the satellite to its mission orbit. This final stage will last approximately three months. Phase one and phase two involved firing smaller thrusters. They concluded on Sept. 7 and Sept. 22, respectively.