Studies of plume condensation contamination upon surfaces of the Terrestrial Planet Finder spacecraft

There are two competing concepts for the Terrestrial Planet Finder (TPF) mission, one which involves a single spacecraft, and another comprised of a five craft formation. In addition, there are several propulsion options under consideration. Unique contamination issues affect the formation-flying concept due to the close proximity of the spacecrafts. Select surfaces must be maintained at the low temperature of 40 K. There is concern that propellant expelled from one craft will condense on the cryogenic surfaces of a neighboring craft, adversely affecting performance and the integrity of the observational data. The condensation properties of warm Xenon, Krypton, and Argon upon a cryogenically-chilled QCM were characterized at a range of temperatures and pressures. Heats of adsorption were predicted with a model to solve for intermolecular forces, and experimental data was used to assess the model's validity. Knowledge of the heat of adsorption was used to determine the equilibrium level of surface coverage for both a pulsed and constant operation thruster, for a range of impinging gas fluxes. The model aims to aid in the selection of an appropriate propulsion system and propellant for the TPF spacecraft.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Pigeon, Timothy David

Advisor dc:contributor.advisor

• Manuel Martínez-Sánchez.

• Aeronautics and Astronautics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/34680

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/34680