File(s) under embargo
Reason: Specific contents of the file are under review by a journal.
until file(s) become available
A Morphable Entry System for Small Satellite Aerocapture at Mars
As space agencies look to conduct more scientific missions beyond Earth orbit, low-cost access to space becomes indispensable. Small satellites (smallsats) fulfill this need as they can be developed at a fraction of the cost of traditional large satellites. Consequently, smallsats are being envisioned for planetary science missions at several destinations including Mars. However, a significant challenge for interplanetary smallsats is performing fully-propulsive orbit insertion because modern smallsat propulsion technologies have limited total velocity change capabilities. At destinations with significant atmospheres, this challenge can be circumvented via aerocapture, a technique that uses a single atmospheric pass to convert a hyperbolic approach trajectory into a captured elliptical orbit. Aerocapture has been shown to enable significant propellant mass savings as compared to fully-propulsive orbit insertion, making it an attractive choice for smallsats. Performing aerocapture with smallsats requires a suitable vehicle design that satisfies the associated control requirements and volumetric constraints. To address this requirement, this dissertation proposes the morphable entry system (MES), a conceptual deployable entry vehicle that utilizes shape morphing to follow a desired atmospheric flight profile during aerocapture. The aerocapture performance of the MES at Mars is investigated using a six degree-of-freedom aerocapture simulation environment. The shape morphing strategy employed by the MES is shown to be feasible for targeting desired angle of attack and sideslip angle profiles that lead to successful orbit captures. Furthermore, the robustness of the MES to simulated day-of-flight uncertainties while employing angle of attack control is demonstrated through a Monte Carlo dispersion analysis. The major contributions of this research as well as areas of future work are described.