Flight Performance of the MESSENGER Propulsion System from Launch to Orbit Insertion

Abstract

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission was designed to unlock the secrets of our solar system’s innermost planet, revealing clues to the planet’s enigmatic geological history, unusually high density, and radar-reflective materials at the poles, among many other decades-old unanswered questions. MESSENGER began its journey on 3 August 2004, when it was launched from the Cape Canaveral Air Force Station in Florida, and the spacecraft was successfully inserted into its destination orbit about Mercury on 18 March 2011. On its way to Mercury, the MESSENGER spacecraft completed 12 trajectory-correction maneuvers, five deep-space maneuvers, and one critical Mercury orbit-insertion maneuver. The MESSENGER dualmode propulsion system is composed of 12 monopropellant Aerojet 4.4-N MR-111C thrusters, four monopropellant Aerojet 22-N MR-106E thrusters, and one large bipropellant AMPAC In-Space Propulsion (ISP) Leros 1b 660-N engine. This paper describes the operation and performance of the propulsion system during the MESSENGER spacecraft’s interplanetary cruise phase and through its insertion into orbit about Mercury.