Length Scaling in Spacecraft Dynamics

Length-scaling represents a new degree offreedom for spacecraft mission design. This paper presents a method for comparing the length scales of arbitrary spacecraft and uses this approach to evaluate the relevance of 12 environmental forces and torques. Three sample spacecraft geometries are considered: a sphere, a cube, and a thin square plate, at three near-Earth altitudes: 500, 1000, and 10,000 km. This analysis offers a guide for orbit and attitude simulations of small bodies, by suggesting which effects can and cannot be neglected for a given environment and error tolerance. This approach to length scaling may enable extremely small spacecraft to exploit unfamiliar dynamic behaviors that result in solar sail maneuvers, atmospheric reentry, and Lorentz propulsion.