Masters Theses

Date of Award

5-1998

Degree Type

Thesis

Degree Name

Master of Science

Major

Engineering Science

Major Professor

Gary A. Flandro

Committee Members

Peter Solies

Abstract

The Mars split Design Reference Mission set forth by NASA MSFC HMM Preliminary Design Study plans for two cargo flights to launch on November 8,2011 and a piloted mission to launch on January 20,2014. The cargo missions are planned to have a 297 day time of flight, and the piloted missions are planned to have a 161/154 day outbound/return time of flight. The cargo missions are planned to deliver return habitat, in situ propellant production plant and other systems. The crew is set to stay on the Mars surface for 569 days. Upon arrival all missions will perform an aerocapture maneuver into Mars parking orbit. From there each vehicle will descend to the surface. After 569 days on the surface, the crew will ascend using the in situ produced propellant and rendezvous with the return vehicle. The crew will depart Mars orbit on January 24, 2016. Upon arrival at Earth, the crew vehicle will perform a direct reentry to the surface.

This thesis studies the alternatives of Solar Electric propulsion and Solar Sail propulsion in place of the impulsive options used in the design reference cargo missions. The ability to use long flight times for the cargo missions causes low thrust propulsion to become an attractive alternative. Solar Sail and Solar Electric missions are optimized using Pontryagin's Maximum Principle and are directly compared with the Design Reference Cargo Missions. It is found that each low thrust mission provides substantial improvements of initial mass in low Earth orbit with little change in the overall mission Architecture.

The outbound and return flights of the piloted mission are fast transit flights consisting of 161 and 154 days. This thesis also takes a look at these trajectories. Improvements in energy and mass cost occur as a result of increasing the flight times. Entry velocities of the spacecraft are also analyzed, and it is shown that longer flight times also create an improvement in the arrival velocities.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS