NASA Lunar Module “Orion” Pilot Charles Duke takes in the view across the hilly Descartes Highlands, the Command and Service Module “Casper” above the lunar horizon, Commander John Young’s “giant leap,” the lunar rover, and a photo of Duke and his family on the moon’s surface, created by “Apollo Remastered” author Andy Saunders.
Saunders, who has previously posted remastered photographs of the Apollo 15 moon landing, updates his Twitter and Instagram accounts on a regular basis.
Apollo 16’s primary objectives were to inspect, survey, and sample materials and surface features in the highlands region of the moon’s southeast quadrant, to position and activate surface experiments, and to conduct in-flight experiments and photographic tasks from lunar orbit, which was the second of the three “J-missions.”
The astronauts took off from Launch Complex 39 at Kennedy Space Center in Florida at 12:54 p.m. EST on April 16, 1972, aboard the Saturn-V SA-511 rocket.
The Lunar Module carrying Young and Duke arrived at Descartes at 9:24 p.m. EST on April 20, about six hours late and 276 metres northwest of the targeted landing site.
Two serious Command Module issues, one en route to the moon and the other in lunar orbit, contributed to the mission’s one-day delay in landing and its early termination.
During the translunar coast phase, an erroneous signal signalling guidance system gimbal lock was neutralised by real-time programming, but the backup circuit caused yaw oscillations in the service propulsion system, delaying the circularization burn of the Command Module.
The landing of the Lunar Module was postponed until engineers concluded that the oscillations would not have a significant influence on Command Module steering.
Astronauts investigated the region on three extravehicular activities (EVAs) totaling 20 hours and 14 minutes during their more than 71 hours and two minutes on the surface.
The Heat flow experiment was lost after Young stumbled on and broke the electronics cable during the first EVA, which included the configuration of the Lunar Roving Vehicle and the deployment of the Apollo Lunar Surface Experiments Package (ALSEP).
At Spook Crater, the astronauts performed the first measurement with the lunar portable magnetometer and deployed the solar wind composition experiment at the ALSEP site.
During the second EVA, they gathered core, surface, and trench samples in the area of Cinco Craters, and lunar portable magnetometer measurements were obtained near Cinco.
The third EVA was cut short due to a time limitation in meeting the ascent timetable, but it included sampling the crater rims of “House Rock” and “Shadow Rock,” as well as readings from the lunar portable magnetometer there and at the rover parking site, as well as final samples. Finally, they used the far ultraviolet camera/spectroscope to retrieve the solar wind composition and film.
With cameras and the Scientific Instrument Module (SIM) bay instruments that were functioning throughout Young and Duke’s surface stay, Command Module Pilot Thomas K. “Ken” Mattingly orbited the moon and validated Apollo 15 data and information about lunar geography.
Young and Duke had collected 209 pounds of material and driven the rover 16.6 kilometres by the time it came to an end.
On April 23, at 8:26 p.m. EST, the Lunar Module was launched into orbit.
After normal rendezvous and docking, the lunar module was discarded and altitude was dropped, obviating the need for the typical deorbit manoeuvre and planned impact.
After Mattingly’s 83-minute spacewalk to film cassettes from the SIM bay, the mission was returned a day early, splashing down in the Pacific Ocean just before 3 p.m. EST on April 27.
The mission took 265 hours and 51 minutes to complete, or little over 11 days.
The Particles and Fields subsatellite, for example, was launched on April 24 at 4:56 p.m. EST to study the moon’s mass and gravitational changes, as well as the particle composition of space around the moon and the interaction of the moon’s magnetic field with Earth’s.
When Mattingly identified a malfunction with the Command Module’s main engine, the three astronauts had to visually station-keep in lunar orbit for the four hours it took Mission Control to analyse the problem, according to Saunders.
According to Saunders, a photograph shot by Duke, which shows the Command Module hovering above the lunar surface as the blue Earth rises, captures the magnitude of their accomplishments.
It was an emotional occasion for Duke, who left a portrait of his family on the lunar surface following the third EVA.
Saunders is sending a copy of the photograph back to the moon in a small capsule this year on the unscrewed Astrobotic Peregrine lander, despite the fact that the shot had likely faded and curled up.