391. [Apollo 16] JOHN YOUNG DEPLOYING EXPERIMENTS AT THE SUNLIT DESCARTES SCIENTIFIC SITE Charles Duke, 16-27 April 1972, EVA 1 Printed 1972. Vintage chromogenic print on fibre-based Kodak paper [NASA image AS16-114-18374]. With NASA caption and "A Kodak Paper" watermark on the reverse, numbered "NASA AS16-114-18374" in red in the top margin (issued by NASA Manned Spacecraft Centre, Houston, Texas). 20.3 x 25.4 cm. (8 x 10 in.) Historical context Bathed in brilliant sunlight, John Young is seen working among the scientific instruments of Apollo 16's Descartes landing site, a scene that captures both the stark beauty of the lunar landscape and the meticulous human effort to explore and understand it. Young is near the Central Station and the RTG (Radioisotope Thermoelectric Generator), using the thumper device to activate the geophones of the Active Seismic Experiment, which would help scientists analyse the Moon's subsurface structure. In the foreground, the deployed magnetometre stands ready to measure the Moon's weak magnetic field. Apollo 16's ALSEP (Apollo Lunar Surface Experiments Package) was one of the most extensive scientific deployments of the Apollo program, requiring both precise execution and thorough photographic documentation for future analysis. As Charles Duke later recalled: "We practiced all the photographic sequences that we had. Every time we put out the ALSEP in training, we would go through not only the experiments deployment but we'd go through the photo layout and sequence so we knew what to do and it was second nature." —Charles Duke (ALSJ mission transcript at 122:13:07 GET) From the mission transcript as Young completed his task: 122:20:26 England (Mission Control): And, Charlie, while you're taking the pictures and all, verify the area around the Central Station is policed up. 122:20:37 Duke: Okay, I will. [...] 122:21:05 Young: Okay. Coming up on the last one (thumper firing). [...] Going up here by the Central Station. (Pause) Going to fire it at the white line next to the first geophone. [...] 122:21:36 Duke: Wait a minute, John. (Pause) Okay. Go ahead. 122:21:41 Young: Okay, Houston. Last one. 4, 3, 2, 1, Fire.