END OF LIFE OF SPOT1 - BEHAVIOR OF THE PROPULSION SYSTEM AND AOCS SUBSYSTEM DURING THE LAST DEORBITING MANEUVER

摘要

After 17 years in orbit, SPOT1 has been de orbited from its operational orbit, by a sery of manoeuvres using its hydrazine propulsion system. After a brief description of the SPOT1 propulsion system, this paper will focus on the behaviour of the propulsion system and AOCS during the last 2400 s manoeuvre which occurred on 28th 11 03. The propulsive parameters (tank pressure, temperatures) and AOCS parameters (attitude, and angular velocity) will be reported and correlated, showing that hydrazine run out has occurred after the target of minimum perigee has been achieved. After a short mission analysis for the SPOT-1 decommissioning selecting a safety solution to avoid creating more debris and that will allow a reentry of the satellite within 25 years.