28. Geological Observations From Lunar Orbit

Visual observations from orbit were first con-àdered as a mission objective on Apollo 15. The concept and means of achieving the objective are described in reference 28-1, and summaries of the results have been published (refs. 28-2 to 28-4). Observations were also made from the command module (CM) during the Apollo 16 mission, and the results provided additional data which complemented the photographs and the geochemical remote sensing (refs. 28-5 and 28-6). As on previous missions, the Apollo 17 crew (the command module pilot (CMP) in particular) was trained during a 2-yr period before the flight for the task of making the observations. During this training, the CMP conducted simulations of the task by studying aerial photographs of geologically complex regions in the United States and by flying over these regions to make on-the-scene interpretations. Because the Apollo 17 groundtracks repeated approximately 80 percent of the lunar surface area previously overflown on Apollo 15, much was already knovra about the features in question. For this reason, emphasis was largely placed on color tones of geologic units and details of small-scale features. Observations were made from the CM windows without disturbing the operations of the scientific instrument module. The tools available were limited to a booklet of graphics (some of which are shown here as examples), a pair of lO-power binoculars, a reference color wheel, two hand-held cameras (Hassel-blad and Nikon), and voice-recording equipment. The Apollo 17 crew made observations from orbit of 14 lunar surface areas (fig. 28-1). As shown in table 28-1, four of these targets were not formally scheduled in the flight plan. A brief summary o