Date of Award

Spring 11-22-2016

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Astrophysical & Planetary Sciences

First Advisor

Webster Cash

Second Advisor

John Bally

Third Advisor

Zachory Berta-Thompson

Fourth Advisor

Jeremy Darling

Abstract

One of the most important scientific discoveries to be had this century is the spectroscopic characterization of Earth-like exoplanets to determine the occurrence rate of worlds capable of supporting life and to potentially answer: are we alone in the universe? To accomplish these lofty goals requires an advancement in the technology to separate the overwhelming starlight from that of the exoplanet. I believe starshades are the key technology that will enable these discoveries within our lifetime. This dissertation work is a contribution to the advancement of starshade technology to put us on the path towards discovery.

In this dissertation I present a number of suborbital methods developed for testing small-scale starshades, which include a Vertical Takeoff Vertical Landing rocket, the surface of a dry lake bed, and the heliostat of a solar telescope. The results from our high contrast observations are used to validate the optical model I developed to conduct tolerance analyses that will drive future starshade designs. The results from testing a formation flying sensor on the VTVL rocket demonstrate the rocket’s potential for conducting starshade experiments in the stratosphere.

This dissertation (along with [Novicki, et al. (2016)]) presents the first astronomical observations with a starshade that provide photometric measurements of stars, previously unobserved in the visible spectrum, in the proximity of Vega. These observations led to the development of a visual feedback system for the heliostat that allows us to push farther in separation and inner working angle. These high contrast observations were made using a starshade in the most flight-like configuration (in terms of Fresnel number, inner working angle, and resolution) to date.

The results of this dissertation have helped demonstrate the effectiveness and practicality of starshades for starlight suppression and have outlined a path forward to further advance starshade technology through optical testing and high contrast astronomy.

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