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Apollo 15 & Apollo 16

photo of Apollo 15 Endeavor
Credit: NASA

* Mission Overview

Apollo 15 and 16 were launched on 26 July 1971 and 16 April 1972, respectively. Splashdowns were 7 August 1971 and 27 April 1972. Both released sub-satellites while in orbit around the Moon to do studies on lunar gravity and magnetic fields. Apollo 16 astronauts John Young and Charles Duke deployed a UV electrographic camera/spectrograph on the lunar surface. The instrument observed the Sun, the Earth's geocorona and various astronomical objects. Both Apollo 15 & 16 Command Service Modules carried gamma-ray spectrometers. These spectrometers studied the Moon and the gamma-ray background.

* Instrumentation

Apollo 15 and 16 carried a 512-channel cylindrical NaI(Tl) scintillation gamma-ray spectrometer, 76x76 mm in size, covered with a plastic scintillator for charged particle rejection. The instrument covered the energy range 0.55-8.6 MeV. The resolution of the spectrometer was about 8%.The sensor was mounted on a 7.6 m long boom.

* Science

Primarily intended to study the Moon's radioactivity, it made measurements of the cosmic gamma-ray background during its trip. A flux density of ~1x104 quanta/m2/s was observed.

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