This experiment was deployed on Apollo 11, 12, 14, 15, and 16 to determine the chemical composition of solar wind. The moon provided an excellent location to study solar wind because, unlike the Earth, it has no magnetic field to deflect solar wind and no atmosphere to absorb it. The solar wind composition experiment consisted of an aluminum (or in the case of Apollo 16, aluminum and platinum) foil sheet erected on a pole. The charged particles comprising the solar wind would embed in the foil, which would be taken back to Earth for analysis.
It was donated to the Smithsonian by the experiment's Principle Investigator in 1974.
Donated by Dr. J. Geiss, University of Bern