Foil: 17 Panel: 3 Column: 1 Line: 62

Wall of Honor Level:
Air and Space Friend

Honored by:
Ms. Frances J. Raab

A. Robert Raab, Ph.D. conducted a three-dimensional finite element stress analysis of the sunlight-induced thermal deformations of the retroreflector "corner cubes" of the Lunar Laser Ranging Experiment of the Apollo 11 mission while employed as a staff structural engineer by the Itek Corporation of Lexington, Massachusetts in the late 1960's. The laser reflector consists of 100 fused silica corner cubes mounted in a 46centimeter square aluminum panel. Each corner cube is 3.8 centimeters in diameter. Corner cubes reflect a beam of light directly back toward the point of origin. By beaming laser pulses at the reflector from Earth, scientists have been able to determine the round-trip travel time that gives the distance between the two bodies at any time to an accuracy of about 3 centimeters. This analysis was a key component of the design of the aluminum panel that supported the reflector array which was placed in the Sea of Tranquility in 1969 by the Apollo 11 astronauts Neil Armstrong and Buzz Aldrin.

Dr. Raab's fascination with the magic and science of flight began in the early 1950's, when, as a teenager, he built and flew rubber-powered, balsaand-tissue, model airplanes. To him, there was both magic and science in the stack of wood and paper that could be assembled into something that would fly. His interest in model aircraft took a serious turn in the 1970's, when, while employed as a staff member of the Mitre Corporation of Bedford, Massachusetts, Dr. Raab developed military mission descriptions for remotely piloted vehicles used for aerial reconnaissance by "pilots" situated on the ground and miles behind the battle line. In the 1980's, he resumed building and flying model airplanes as a member of the MIT flying club in Cambridge, Massachusetts. In 1993, these models were acquired by The Waltham Museum in Waltham, Massachusetts, where they are now on continuous display. In 2000, he returned again to building model airplanes as a member of the DC Maxecuters in the Washington, DC area. He flies his planes regularly at club-sponsored sessions at the National Building Museum in Washington, DC.