SwRI TAPP Project Analysis and Add-On System Proposal - Abstract
SwRI TAPP Project Analysis and Add-On System Proposal

Andrew Grimes, et. all

December 7, 1994

Executive Overview

United Space Satellites Enterprises (USSE) was contracted to perform the task of the Southwest Research Institute Twin Auroral Plasma Probe (TAPP) analysis and add-on system design. The TAPP mission uses two spacecraft in matching polar orbits, one following the other. The mission of these spacecraft is to analyze the ion and electron plasma flow around the north and south poles which cause the auroras. These spacecraft together only weigh 72 kg, so there is a sizable mass margin left over to use for either a separate spacecraft or additional systems on the TAPP spacecraft. The main task of this contract is to develop an add-on system to utilize the mass margin.

The chosen add-on system is a solar sail demonstrator. This low cost, low mass spacecraft will be launched with TAPP, separated from TAPP, inserted into an Earth escape trajectory by a Star motor, and then deployed on a trajectory to Mars. The goal of the mission is to prove the feasibility of using solar sails to reach Mars as part of either a manned or unmanned Mars mission in the future. The solar sail designed by USSE is a helio-gyro, consisting of long, flat panels of mylar unrolled from a slowly spinning central bus. The light pressure of the Sun's radiation on the mylar produces a force on the spacecraft, giving it an acceleration. By tilting the angle of each panel, the spacecraft can be pointed in desired direction and be controlled.

Other tasks in the contract are the analysis of the TAPP design, design of a student manned control center for TAPP and the solar sail, and design of a mission scenario for the solar sail mission. The bulk of the project focuses on designing the subsystems for the solar sail spacecraft. USSE has completed this project on time and within budget.