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CATSAT Update by Frank Hludik As in the recent issues of Signals and Noise, we will continue to keep you updated about the Cooperative Astrophysics and Technology Satellite (CATSAT) project. NASA funds the project through the Student Explorer Demonstration Initiative (STEDI) program of the University Space Research Association (USRA). The STEDI program seeks to demonstrate that university-led teams can successfully carry out high-quality space science and technology missions for relatively low cost on a time scale of two years from go-ahead to ready-for-launch. Students and entry-level professionals are closely involved in every aspect of this pilot program. Supervised by experienced space scientists and engineers, the students gain invaluable hands-on experience in the design, development, test, and operation of a real space project. Three projects were selected from a total of 66 proposals submitted: the University of Colorado’s SNOE, Boston University’s TERRIERS, and the University of New Hampshire’s CATSAT. The University of Colorado's Laboratory for Atmospheric and Space Physics is teamed with Ball Aerospace on a satellite project, the Student Nitric Oxide Explorer (SNOE), designed to measure nitric oxide density in the lower thermosphere (90-200 km altitude) and to analyze the solar and magnetospheric influences that create it and cause its abundance to vary dramatically. SNOE ("snowy") was launched on a Pegasus launch vehicle from the Western Test Range in February 1998. SNOE completed its first year of operations on February 26, 1999. The spacecraft continues to perform well, and scientific results have exceeded expectations. For further information contact their WWW site at http://lasp.colorado.edu/snoe. Boston University's Tomographic Experiment using Radiative Recombinative Ionospheric EUV and Radio Sources (TERRIERS) was designed to utilize space and ground-based instruments to make daily global upper atmospheric measurements. Using tomography to measure ultraviolet light emissions, TERRIERS was designed to survey the upper atmosphere and utilize the technique to study ionospheric/thermospheric processes. The spacecraft was successfully launched at 1:09 a.m. EDT Tuesday morning, May 18, 1999 from Vandenberg Air Force Base, Calif., aboard an Orbital Science Corp. Pegasus rocket. The first indication that the spacecraft was not properly oriented to the sun came on the second pass over the Boston University ground station at 8:38 a.m. EDT. Controllers sent commands to the spacecraft to aid in acquiring the sun on the third pass at 10:15 a.m. EDT. Unfortunately, Boston University TERRIERS team members were unable to communicate with the satellite from the ground station at the 8:14 p.m. pass over Boston on Tuesday, May 18 and further communications were not established. The WWW site for the TERRIERS project is http://net.bu.edu/terriers.html. CATSAT’s scientific objective is to provide the first direct measurement of the soft X- ray burst spectra at energies less than 1 keV. X-ray absorption produced by material around the burster source and by the intervening interstellar gasses, between the instrument and the cosmic burst source, changes the spectral shape in this energy band. No existing or other currently planned mission can realistically measure these quantities. While CATSAT will only be able to make these measurements for the brightest bursts (fluence greater than10-5 erg/cm2), these results, when placed in context by CATSAT's simultaneous measurements of conventional burst parameters, will allow probing emission models. CATSAT is still alive and well at UNH. ECE students are very active in the development of the satellite. Jeffrey Butler and Ryan Rousseau both graduated after completing their undergraduate and graduate studies in our department. Jeffrey’s master’s thesis is the "Development of an Operating System for Use on the Cooperative Astrophysics and Technology Satellite." Jeffrey was instrumental in developing CATSAT’s operating system and a number of hardware interfaces. Ryan’s master’s thesis is "The Spectral Accumulator Board for Use on the Cooperative Astrophysics and Technology Satellite." Ryan’s Spectral Accumulator System interfaces the eight analog electronics boards to CATSAT’s digital electronics unit. Jeff and Ryan are the second generation of CATSAT funded graduate students. Thanks to Jeff and Ryan for their hard work and dedication to the project; we wish them well in their engineering careers. Brian King, an ECE senior, is continuing his work on the mission and payload high and low voltage power subsystems. David Saarinen, an ECE senior, currently is designing the flight sun sensor that helps keep CATSAT’s solar panels facing the sun. Mike Sandiford, an ECE graduate student, is continuing with the testing of the hard X-ray and directional gamma ray spectrometer subsystems. Joel Mellin, who remained on the CATSAT project after receiving his bachelor’s degree in ECE from our department in 1998, will be attending graduate school at NYU. Joel, who will major in Music Technology, just recently built his own Theremin, a type of early electronic music synthesizer. A number of new ECE undergraduates joined the CATSAT team this spring and summer. Kevin Meyer, an ECE senior, is integrating and testing the digital electronic subsystems and operating system. Dave Dunham, an ECE senior, is working on the selection and testing of the payload battery system. Fausto Molinet, an ECE senior, is testing the photomultiplier tube subsystems. In October of 1998 two NASA astronauts visited UNH and toured the CATSAT facilities. Astronauts Rick Linnehan, a 1980 UNH graduate, and Jay Buckey, a Dartmouth College professor of medicine, flew on the space shuttle "Columbia" during 1998. This was an exciting visit for the CATSAT team. CATSAT’s launch date has been set for summer 2001. This will be an exciting time for many of the current students as they will be able to participate in the launch and initial operation of CATSAT. Visit the CATSAT WWW site at http://www.catsat.sr.unh.edu. |
