J. Thomas Parr

J. Thomas Parr

Geophysicist

Tom Parr received his S.B. from M.I.T. and his S.M. from Brown University, both in Earth Sciences. His research at Brown (sponsored by the Air Force Cambridge Laboratory AFCRL) was focused on gaining an improved understanding of the microscopic, extraterrestrial dusts which have been accumulating on the surface of the moon since early in the evolution of our solar system. Knowledge of the geochemistry, volume, and size distribution of these dusts was considered essential to the design of a safe lunar landing vehicle.

In 1966 Tom joined the M.I.T. Instrumentation Laboratory (MIT/IL) as a Staff Geophysicist where he supported Alex Koso’s team for the design and testing of the Apollo optics. These comprised the sextant, the scanning telescope, associated software, and the integrated human interfaces to the Command Module's Apollo Guidance Computer. Tom’s early work on the Apollo Program resulted in his rapid promotion to Group Leader. His responsibilities included managing a staff of 8-10 scientists and engineers to review the optics system design and make recommendations for changes, as needed. The team then assisted in the design of a simulator for astronaut training, working with all crew members and providing real-time support for all Apollo missions.

Together the optics system components provided capabilities for inertial reference, platform alignment, and autonomous navigation. Navigational support was implemented with the sextant, designed to measure the angle between selected Earth or Lunar landmarks and a reference star. Alternatively, the sextant could be used to measure the angle between the Earth horizon and a selected star. Issues included errors in geodetic position of the feature used for each sighting, the optical thickness of the Earth’s horizon, and variability in the navigator’s physiological response when making a sighting. These error sources were largely negated by additional training and the use of calibration sightings made early in each mission.

Tom left MIT/IL after the final Apollo mission, just as the Instrumentation Lab became the Charles Stark Draper Lab.  His experience at MIT led to a natural and rewarding evolution in his career, specializing in remote sensing and related image processing and geophysics technologies. He became a Principal Investigator for NASA in the use of SIR-B imagery for characterizing surface lithology and later to assess prospective deposits of rare metals in Greenland, using LANDSAT multispectral imagery. His interests now focus on the fusion of data from multiple sources, particularly airborne and space-based hyperspectral scanners and LIDAR systems.