Date of Award

12-2011

Degree Name

MS in Aerospace Engineering

Department

Aerospace Engineering

Advisor

Eric A. Mehiel

Abstract

Current CubeSat communication technology limits the amount of time, and number of accesses with ground stations. It has been proposed to use a constellation of CubeSats to improve relay performance and increase the number of accesses between a CubeSat and ground stations. By using the spatial and temporal analysis features of STK, coupled with the STK/Matlab interface a robust tool was created to analyze the performance of CubeSat constellations based on a store-and-forward communications model which is not currently supported by the STK Engine. Utilizing the Connect messaging format through a socket connection on the local machine, a Matlab graphical user interface, called SATCAT, was constructed in order to provide a user with the ability to control many aspects of the STK Engine externally. A function was created to use three Time Ordered Access (TOA) reports from STK to determine how long it would take for data to be relayed from a target to a ground station through a constellation of CubeSats. Three sample scenarios were created to demonstrate the use and performance analysis capabilities of SATCAT. The performance of a single CubeSat was analyzed and compared to the performance of a three CubeSat constellation and a thirty-seven CubeSat constellation. It was shown that a constellation of three CubeSats decreased the average relay time from 328 minutes to 149 minutes and a constellation of thirty-seven CubeSats further reduced the average relay time to only 3 minutes. While decreasing the average relay time, the constellation of three CubeSats also increased the number of accesses over a twenty-four hour period from 6 to 36, and the constellation of thirty-seven CubeSats allowed for 564 accesses.

CubeSat Constellation Analysis for Data Relaying - Supporting Files.zip (432 kB)
Matlab files and supporting documents for use

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