Aerobraking Technology for Earth Orbit Transfers

This paper addresses the development of an innovative aerobrake concept that utilizes the drag caused when a spacecraft dips into the upper atmosphere to change orbits inexpensivelyand with little or no propellant expenditure. This patented process (U.S. Patent # 6,286,787 issued 11 Sep 2001) enables small satellites to launch using low-cost secondary payload slots on large launch vehicles yet still reach a custom orbit to perform their mission. This paper presents analysis of the orbit transfer process using an aerobrake device. This includesdetailed trajectory simulations that incorporate atmospheric and lunar effects. A detailed trajectoryanalysis of a sample mission reviewing atmospheric effects and uncertainties (altitude/densityvariations with sunspot activity, etc.) is presented, along with a method for planning appropriate aerobraking trajectories. The attitude dynamics of the shuttlecock-shaped vehicle during aerobraking passes are presented. Model results from analysis tasks performed in collaboration with NASA Langley Research Center(LaRC) are presented. Gloyer, Paul 116th Annual/USU Conference on Small Satellites