Pair with Virginia ties played roles in Apollo 11 mission

  A former Virginian played a major role in the Apollo 11 moon landing, and a Richmond native was responsible for a major experiment that Neil Armstrong and Buzz Aldrin placed on the moon during their 2-hour lunar excursion.
  John C. Houbolt, now 90 and a former resident of Williamsburg, was an engineer at NASA’s Langley Research Center.
  He campaigned hard for a moon-landing mission plan, which ultimately permitted the program to achieve its goal of landing and returning men from the moon within the decade of the 1960s. Otherwise, the mission would have taken much longer and would have been more expensive and complicated than it was, and it would have seriously missed the deadline set by President John F. Kennedy.
    The original plan for the mission was to carry it out with a direct flight to the moon and to return directly to Earth from the moon. That would have meant powerful rockets with massive amounts of fuel, not to mention complex issues of launching a powerful rocket from the moon.
    For one thing, the time delay would rule out real-time assistance from a fully staffed earthbound mission control because it takes a radio signal about 1.3 seconds to go from Earth to the moon, and another 1.3 seconds for a return signal from the moon.
    Houbolt promoted the plan that saved the mission—lunar rendezvous. Place the capsule with the astronauts in a moon orbit; use a separate vehicle—a lunar lander attached to the capsule—to convey two men to the surface; blast the lander from the moon at the end of the lunar exploration into lunar orbit, where it rejoins the orbiting capsule.
  Because the moon’s gravity is only a sixth of the Earths, it would be easier and more economical to launch something into lunar orbit than to blast a vehicle directly to the Earth from there, Houbolt argued.
    At first, top space officials were skeptical, but Houbolt persisted until they became convinced.
    He has since been honored many times for making the Apollo 11 mission—and subsequent moon-landing missions—possible within Kennedy’s deadline. 
    One of the major experiments that Armstrong and Aldrin deployed during their moonwalk was a set of special reflectors that were designed by a team led by Richmond native Carroll Alley, a University of Richmond undergraduate and longtime member of the physics faculty at the University of Maryland.
    Once in place, researchers at various observatories around the country and world could fire laser beams to the reflectors and record their return beams. Among other things, the laser reflector experiments are enabling scientists to determine Earth-moon distances with incredible accuracy; giving scientists remarkably precise values for the gravitational constant and the rates continents on Earth are drifting apart; and providing accurate tests of Einstein’s theory of relativity.
    Additional reflectors were placed on the lunar surface by later moon-walking astronauts, and the laser ranging studies are continuing to this day. Alley lives in College Park, Md.