Explorer 11

Explorer 11 ( also called S 15 ) was a satellite of the U.S., was successfully launched on April 27, 1961 as part of the Explorer program.

Start

The 37.2 kg satellite was launched on April 27, 1961 at 14.10 UTC clock with a rocket of the type Juno II from the launch pad LC -26 B of the Cape Canaveral Air Force Station.

Mission

Mission objective was to investigate gamma rays. For this purpose, the satellite was oriented not only to the Earth's atmosphere. Even the sun and the galactic center should be investigated.

As an instrument for the measurement of gamma radiation Phoswich a quartz Cerenkov detector. It was the first device of its kind that has ever been used in space. It was developed by William L. Kraushaar at MIT.

As the satellite could not be aligned correctly, he was transferred to a rotation in order to capture as the planned areas at least partially can. In addition, he was taken to a higher than originally planned orbit. Due to the detector interfering radiation of the Van Allen belts and a failure of the on-board recording device only 141 hours of data transmitted were useful.