In-orbit operations of AGILE mission: 11 years successfully in space

Abstract

Astrorivelatore Gamma ad Immagini LEggero (AGILE) is a high-energy scientific space program funded by the Agenzia Spaziale Italiana (ASI—Italian Space Agency); the mission was developed and is being operated in cooperation with INAF, INFN, CIFS and with the participation of several Italian companies. The satellite was launched from India on April 23rd, 2007 in an LEO equatorial orbit. The scientific payload includes: an imaging detector for hard X-rays (20–60 keV), an imaging gamma-ray detector (100 MeV–10 GeV), and a calorimeter (0.4–100 MeV). As of today, more than 57,700 orbits have been successfully completed with the satellite in operations more than 11 years (well beyond the 2-year nominal lifetime). This paper describes the operational activities performed at the ground segment level (satellite control and user segment) and discusses the high performance achieved during 11 years of successful in-flight operations. This result was obtained in the framework of a small mission and with a relatively small operation team. Important factors have been the implementation of an efficient automatic ground segment telemetry processing and a very fast scientific alert system. The service consists in the operational management of the satellite and of the ground segment in different phases of the mission both in nominal and contingency situations, carrying out the observations plan provided by ASI and the delivery of the scientific data to the ASI Space Science Data Center (SSDC, formerly ASDC). To achieve these objectives satisfying the mission safety requirements, specific operational procedures and strategies have been implemented together with ground segment automation and optimized use of onboard satellite capabilities. This work has been carried out under an ASI contract.