Ph.D. Dissertation Proposal

by

Alexandra Cheryl Long

Advisor: Dr. David Spencer

Development of a passively stable pyramid sail ([PS]2) to deorbit small satellites

3:00 PM, Monday, January 30, 2017

Montgomery Knight Building

Room 317

ABSTRACT:

Orbital debris is a growing problem in low-Earth orbit; it has crossed a threshold of critical density where the number of debris objects will grow exponentially due to collisions unless actively mitigated. There are a number of commercial companies that intend to launch hundreds to thousands of micro-satellites in Low-Earth Orbit at altitudes ranging from 1,000-1,200 km with the goal of providing global internet service. The need to deorbit these microsatellites at the end of their operational lifetime is apparent.  This study investigates a standardized bolt-on system to address the deorbit problem for microsatellites, with applicability to planned large constellations of 150 kg-class satellites at 1,100-1,200 km altitudes. Through a trade study, it was determined that a passive drag sail device provides a reliable approach for satellite deorbit.  To reliably deorbit within 25 years, the drag sail should be designed to provide aerodynamic stability, trimming to a maximum drag attitude. A stability analysis determine that the sail should be a square pyramid shape with an apex half-angle of 75° to ensure stability. Prototype hardware development for the drag device is planned, with three main phases. The first is the boom deployer design and analysis, which includes prototype development and an analysis on boom blossoming in the system. The second is the sail mounting design, which includes connecting the sail segments to the booms and folding them for the stowed configuration. The final phase is the system prototype testing to ensure that the booms and sails deploy together creating the desired shape.

Committee Members:

Dr. E. Glenn Lightsey

Aerospace Engineering

Georgia Institute of Technology

Dr. Julian Rimoli

Aerospace Engineering

Georgia Institute of Technology

Mr. Mark Schoenenberger

Atmospheric Flight and Entry Systems Branch

NASA Langley Research Center

Mr. Les Johnson

Advanced Concepts Office

NASA Marshall Space Flight Center