Technical Paper
Determination of Optimum Thermal Phase Angles at Mercury Perihelion for an Orbiting Spacecraft
1999-07-12
1999-01-2123
Due to the elliptical shape of Mercury’s orbit and the slow planetary spin rate, Mercury has a large surface temperature difference that creates highly variable spacecraft thermal environments that are a function of both planet solar distance and spacecraft orbit plane position. Being able to analytically simulate the severe thermal environments experienced by a spacecraft over the lifetime of a Mercury orbiting mission make it possible to realize a feasiable spacecraft thermal design. The analysis described throughout this paper was used to characterize the temperature response as a function of initial phase angle conditions (αρ) when referenced at Mercury perihelion for a 3-axis stabilized spacecraft. Variables in the analysis include solar distance, argument of periapsis, and αρ. The selected orbit is highly elliptical, with a 720-minute period and a near polar inclination.