title: Apollo 11 Laser Ranging Retro-Reflector: Initial Measurements from the McDonald Observatory.
abstract: Acquisition measurements of the round-trip travel time of light, from the McDonald Observatory to the Laser Ranging Retro-Reflector deployed on the moon by the Apollo 11 astronauts, were made on 20 August and on 3, 4, and 22 September 1969. The uncertainty in the round-trip travel time was +/- 15 nanoseconds, with the pulsed ruby laser and timing system used for the acquisition. The uncertainty in later measurements of a planned long-term sequence from this observatory is expected to be an order of magnitude smaller. The successful performance of the retro-reflector at several angles of solar illumination, as well as during and after a lunar night, confirms the prediction of thermal design analyses.
authors.forename: C O
authors.initials: CO
authors.lastname: Alley
authors.forename: R F
authors.initials: RF
authors.lastname: Chang
authors.forename: D G
authors.initials: DG
authors.lastname: Curri
authors.forename: J
authors.initials: J
authors.lastname: Mullendore
authors.forename: S K
authors.initials: SK
authors.lastname: Poultney
authors.forename: J D
authors.initials: JD
authors.lastname: Rayner
authors.forename: E C
authors.initials: EC
authors.lastname: Silverberg
authors.forename: C A
authors.initials: CA
authors.lastname: Steggerda
authors.forename: H H
authors.initials: HH
authors.lastname: Plotkin
authors.forename: W
authors.initials: W
authors.lastname: Williams
authors.forename: B
authors.initials: B
authors.lastname: Warner
authors.forename: H
authors.initials: H
authors.lastname: Richardson
authors.forename: B
authors.initials: B
authors.lastname: Bopp