Performance and Design Scaling of Magnetoshells for Outer Planet Drag-Modulated Plasma Aerocapture

The application of drag-modulated plasma aerocapture (DMPA) to outer planet orbiter missions is analyzed in terms of performance results and spacecraft design scaling. The magnetoshell, a magnetized plasma used in place of an aeroshell, generates drag by ionizing, capturing, and magnetically deflecting the atmospheric flow. The plasma is sustained by in-situ gas and kinetic energy at velocities above a certain threshold, which is in excess of 15 km/s for hydrogen flow. The magnetoshell drag is shown to scale with magnetic field strength, enabling continuous modulation of the ballistic coefficient via control of the electrical current to the magnet. A design framework for generating preliminary DMPA mission architectures is presented and a sample design is compared to an existing Neptune orbiter concept that uses an ADEPT drag skirt. Compared to ADEPT, the DMPA architecture is shown to deliver 70% higher orbiter mass and experience 30% lower stagnation heating. It achieves a ballistic coefficient of β = 4 kg/m
²
with a ballistic coefficient ratio of β
_max
/β
_min
=67, both results indicating a high degree of control authority via the continuous drag modulation scheme. Recommendations for using the design framework to optimize arbitrary DMPA architectures are discussed as well as additional considerations for the technological feasibility of a given magnetoshell design.