Solar Wind Composition Experiment

The Solar Wind Composition (SWC ) experiment was the only non-American experiment of the Apollo 11 mission. Particles from the solar wind were caught in an exposed aluminum foil and analyzed after the return from the moon in the laboratory. The target with a size of 1.40 meters by 0.3 meters is known as awning or solar wind sail.

The experiment was largely planned and evaluated at the Physics Institute of the University of Bern, Switzerland. The results include the isotopic ratios of the noble gases helium, neon and argon in the solar wind, upper limits for an atmosphere and a magnetic field of the Moon ( from the narrow directional distribution of particle tracks in aluminum) as well as information on the acceleration mechanisms ( from the energy distribution). The simple, lightweight and successful experiment was performed in all lunar missions, with the exception of the last Apollo 17 mission and the failed Apollo 13 mission, repeatedly. The last execution in Apollo 16, there were two segments of the sail of platinum foil, which allowed a more thorough cleaning.

Drawing of the solar wind sail in transport configuration

Drawing of the solar wind sail of Apollo 11

Modified solar wind sail ( Photo: Apollo 16, NASA image AS16- 117-18849 )