Entries in "experiments"
24 million km laser link
D. E. Smith, M. T. Zuber, X. Sun, G. A. Neumann, J. F. Cavanaugh, J. F. McGarry, T. W. Zagwodzki, Two-Way Laser Link over Interplanetary Distance, Science, 311, 53, (2006), Article.
Clearly one of the coolest "simple" experiments I have seen lately. The MESSENGER spacecraft, which is on its way to Mercury, made a two-way laser link with Earth last May. Apparently, at approximately 24 million km (a true interplanetary distance) that is a new distance record for detecting a laser. The link was made both by the Mercury Laser Altimeter (MLA) pointing at telescopes at NASA's Goddard Geophysical and Astronomical Observatory and simultaneous pointing of an Earth-based laser at the same location toward the spacecraft. The experiment is useful as a calibration of the MLA instrument in space as well as establishing that such an experiment can be accomplished. Two-way laser communication may become important for future spacecraft which need precise distance and other measurements, like the proposed LISA mission to search for gravity waves.
Spacecraft