University of Colorado
An Investigation into Establishing a Formation of Small Satellites in a Lunar Flower Constellation.
Degree: MS, Aerospace Engineering Sciences, 2015, University of Colorado
Lunar science missions such as LADEE and GRAIL achieved unprecedented measurements of the Lunar exosphere and gravity field. These missions were performed with one (LADEE) or two (GRAIL) traditional satellites. The global coverage achieved by these missions could have been greatly enhanced with the use of a constellation of satellites. A constellation of communication satellites at the Moon would also be necessary if a Lunar human base were to be established. Constellations with many satellites are expensive with traditional technology, but have become feasible through the technological advancements and affordability of cubesats. Cubesat constellations allow for full surface coverage in science or communication missions at a reasonable mission cost.
Repeat ground track orbits offer interesting options for science or communication constellations, since they provide repeat coverage of the surface at a fixed time between sequential visits. Flower constellations are a family of constellations being studied primarily by Daniele Mortari at Texas A&M University that make use of repeat ground tracks. Orbital parameters are selected such that the nodal period of the orbit matches the nodal period of the primary body by a factor dependent on the number of days and the number of revolutions to repeat the ground track. All orbits in a flower constellation have identical orbital elements, with the exception of the right ascension of the ascending node (RAAN) and the initial mean anomaly, which are determined based on the desired phasing scheme desired.
Flower constellations have thus far primarily been studied at Earth. A flower constellation at the Moon could be quite useful for science or communication purposes. In this scenario, the flower constellation satellites would be small satellites, which introduces many unique challenges. The cubesats would have limited propulsion capability and would need to be deployed from a mothercraft. Orbital maintenance would then be required after deployment to retain the repeat ground track nature of flower constellations. The limited fuel on the cubesats and the maneuvers required determine the lifetime of the constellation. The communications range of the cubesats will also be limited; following a successful deployment, the mothercraft must move into a long-term communications orbit where it can see both the children craft and Earth, to act as a communications relay.
This work investigates the differences in flower constellations at the Moon versus at Earth. It is found that due to the longer rotation period of the Moon, the number of petals in the flower constellation must be quite large in order to produce reasonable orbit sizes. Two types of flower constellations are investigated: a single-petal and multi-petal constellation. The single-petal constellation consists of a string-of-pearls formation within one inertial flower constellation orbit. The multi-petal configuration has one satellite per inertial orbit, with the orbits spaced symmetrically within a…
Advisors/Committee Members: Hanspeter Schaub, Jeff Parker, Dan Scheeres.
Subjects/Keywords: Aerospace Engineering
to Zotero / EndNote / Reference
APA (6th Edition):
McManus, L. (2015). An Investigation into Establishing a Formation of Small Satellites in a Lunar Flower Constellation. (Masters Thesis). University of Colorado. Retrieved from https://scholar.colorado.edu/asen_gradetds/104
Chicago Manual of Style (16th Edition):
McManus, Lauren. “An Investigation into Establishing a Formation of Small Satellites in a Lunar Flower Constellation.” 2015. Masters Thesis, University of Colorado. Accessed January 17, 2020.
MLA Handbook (7th Edition):
McManus, Lauren. “An Investigation into Establishing a Formation of Small Satellites in a Lunar Flower Constellation.” 2015. Web. 17 Jan 2020.
McManus L. An Investigation into Establishing a Formation of Small Satellites in a Lunar Flower Constellation. [Internet] [Masters thesis]. University of Colorado; 2015. [cited 2020 Jan 17].
Available from: https://scholar.colorado.edu/asen_gradetds/104.
Council of Science Editors:
McManus L. An Investigation into Establishing a Formation of Small Satellites in a Lunar Flower Constellation. [Masters Thesis]. University of Colorado; 2015. Available from: https://scholar.colorado.edu/asen_gradetds/104