Mission Objectives

The purpose of the FASTRAC mission is to investigate enabling technologies crucial for satellite formations, including on-orbit micro-thrust capability, relative navigation, attitude determination, and satellite crosslink communications. This will be achieved by taking on-orbit data from a pair of twin satellites that will separate once in orbit. The data will be gathered through a network of civilian ground stations and evaluated through post-processing of the recombined downlink message.

The FASTRAC nanosatellite mission has three primary technical objectives. On-board the satellite, these include two primary experiments: the microdischarge plasma thruster experiment and the GPS relative navigation experiment. The third technical objective is the construction of a civilian distributed ground station network.

Microdischarge Plasma Thruster

FASTRAC image

The University of Texas Satellite Propulsion Laboratory, under the guidance of Dr. L. Raja, has developed a new satellite propulsion system which is capable of sustaining a microNewton level of thrust. The device works by channeling a superheated gas through a microdischarge plenum. The method of superheating the gas is an innovation in the field of satellite propulsion techniques. The thruster effectiveness will be qualitatively demonstrated by firing the thrusters on the two spacecraft in opposing directions. The thruster system on one satellite will be used to raise its nominal orbit and increase the satellites lifetime, while the other satellite's thruster will be used to decrease its nominal altitude and lifetime. A noticeable difference in the nominal altitude and respective lifetimes of the two satellites will be used as a metric for the thruster's effectiveness in nanosatellite applications. The thruster operation will require autonomous control and may also be used to ensure safe separation of the two nanosatellites.

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GPS Relative Navigation via
Real-Time Crosslink Data Exchange

The University of Texas GPS Laboratory, under the guidance of Dr. E. Glenn Lightsey, has developed a space capable GPS receiver based on the Zarlink\Mitel GPS chipset. Named the Orion, the GPS receiver has been outfitted with a software package designed at the university which allows the receiver to calculate the satellite's position, velocity, and attitude in real-time. With data exchange from another Orion receiver, the relative position, velocity, and attitude between the two satellites can be computed and reported in each receiver's output data stream. The use of a three-axis magnetic sensor will be employed together with the GPS receiver's single antenna signal-to-noise ratio measurements to produce the spacecraft attitude estimates. A cross-strap antenna design will be used along with dual GPS patch antennas to ensure greater GPS constellation visibility.

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Distributed Ground Station Network

The University of Texas at Austin, in conjunction with Santa Clara University (SCU) in California, and Leeward Community College in Pearl City, Hawaii are developing a distributed ground station network. The network will be remotely scheduled and controlled via the RACE ground station network control system developed by SCU. Use of the network will allow for increased downlink opportunity and for the first civilian satellite tracking network of its kind.

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