Two years after Apollo 13 nearly ended in disaster, Young and Duke anxiously anticipated their next moon voyage – Apollo 16. This mission would serve as a trial run for an entirely new generation of space flight.
Geologists had high hopes that the lunar highlands, 30 miles north of worn crater Descartes, would yield volcanic rocks that could give insight into its past.
Landing on the Moon
On April 24th morning, two EVAs began. Their first EVA lasted 7 hours 11 minutes during which time they deployed the solar wind composition experiment and traveled 4.2 kilometers (2.6 miles). Collecting 20 kilograms of samples they returned safely back to lunar module.
As they reached lunar orbit, they noticed a vibration in the LM’s backup engine controls – something which had previously happened and raised alarm. After several tests and analyses it was decided that astronauts could continue towards the Moon without issue.
At the start of their descent to the Moon’s surface, the crew fired the engine again to switch from an nearly circular orbit to one with only minimal closeness (roughly 15,000 meters / 50 thousand feet). They began powering their descent, with five times of landing alarm set off by simulations showing that if astronauts followed these warnings and followed recommended maneuvers then successful landing was possible; they did just this and touched down 6-10 degrees below where it should have.
The astronauts were taken aback when they saw the landscape: an expansive flat expanse of dark blues and purples punctuated with small craters and mountains that was truly remarkable to look upon. It was truly magnificent!
After arriving, they were met by a rover sent by Mission Control to their site. Although initially confusing to control, after some trial-and-error they eventually got it running smoothly.
Before the astronauts could relax for the night, they had one last journey out to their rover at station nine, on the rim of North Ray Crater. There, they took photographs and collected several rocks that became known as House Rock because of bullet-hole-like marks appearing on its surface – this evidence provided conclusive proof against pre-mission theories that North Ray Crater was formed by volcanic forces.
Exploring the Moon
Apollo 16 represented one last chance for the United States to explore the lunar surface before Earth-orbiting space races began gaining ground. Commander John Young, Lunar Module Pilot Charlie Duke and Command Module Pilot Ken Mattingly left Earth on April 16, 1972 on their second of NASA’s scientifically rich “J-class” missions; it would also mark their inaugural attempt at landing with a fully functional lunar rover on the lunar surface.
As well as collecting geology samples and deploying the Apollo Lunar Surface Experiments Package (ALSEP), or astronauts took pictures with Hasselblad 70mm still cameras and Mauer 16mm motion cameras built into their equipment – taking full advantage of their time on the moon, they captured landscapes, family portraits, and the iconic “giant leap” photo!
One EVA involved traveling to Spook Crater where they performed the initial measurements using the Lunar Portable Magnetometer of ALSEP, before driving westward to Flag Crater where astronauts used panoramic and 500mm telephotography photography on their rover to capture more lunar landscape imagery – truly merging science and art!
After performing two more EVAs, the astronauts arrived at Mare Fecundatatis (Mare of Fertility) region. Here they would sample its ejecta blanket, search for areas with unusually strong magnetic fields and study how its atmosphere interacts with lunar surface.
Young and Duke collected their inaugural rock sample here: it was from North Ray crater, which proved challenging to locate due to surrounding ridges; however, their navigation system made quick work of pinpointing their exact position at every turn.
As EVA-3 neared completion, something strange began to happen: Venus – one of the brightest objects in our solar system – began appearing in several images taken during EVA-3 moonwalk. Stellarium and GoneToPlaid both have identified this appearance of Venus in three magazine 117 exposures during EVA-3.
Returning to Earth
On April 27 after spending 71 hours and 2 minutes on the Moon, astronauts John W. Young as commander; Charles M. Duke Jr as lunar module pilot and Thomas K. Mattingly II as command module pilot started their return home aboard Casper from above using Lunar Module Eagle. They approached Casper from above as seen here from Lunar Module Eagle with lunar surface below them. Once they joined up with Casper again they performed a spacewalk by Mattingly to retrieve cassettes from Mapping and Panoramic Cameras as well as inspect equipment before performing a spacewalk to retrieve film cassettes from Mapping Panoramic Cameras as well as expose microbial response experiments to lunar environments for investigation by using Mapping Panoramic Cameras as seen here from Eagle.
Before the EVA began, Apollo 16’s crew prepared the lunar rover for driving by extending and retracting mass spectrometer and gamma ray spectrometer booms attached to the Scientific Instrument Module bay. They made additional modifications to the Lunar Rover Vehicle, such as modifications that enable better extension and retraction of instrument booms. During their seven-hour and 11-minute EVA, they drove the rover to various geologic sites across Cayley Formation-rich soil and collected samples there. Station one also provided the chance to collect rock specimens near landing site. At South Ray Crater, they searched for rocks that may have melted from recent volcanic activity and collected samples of fine-grained material from its floor at Station 6. They passed by Station Seven (Stone Mountain area) to save time, and at Station 8 located along the lower flank of the crater rim they found and recovered the largest rock ever returned from an Apollo mission – an unusual breccia named Big Muley after their geology chief on this mission.
Apollo 16’s crew spent its final lunar orbit reprocessing and analyzing samples collected during its previous missions as well as conducting more experiments with their equipment. A scientific subsatellite similar to that used during Apollo 15 was deployed as a way to gather plasma, particle, and magnetic field data at different locations around the moon. After some unscheduled maneuvering to compensate for an unscheduled vibration Mattingly felt in their Command Module backup propulsion system, Houston gave Orion clearance to return home via lunar descent.
Final Mission
Sweet Sixteen was the final Apollo mission to the Moon, launched from Kennedy Space Center on April 16, 1972 and marked history by visiting two distinct volcanic formations on its surface. Led by Commander John Young, Lunar Module Pilot Charlie Duke and Command Module Pilot Ken Mattingly made this remarkable journey successful and groundbreaking for mankind.
After an uneventful launch, the Lunar Module (“Casper”) and CSM (“Orion”) successfully rendezvoused in lunar orbit the following day. A few hours after they undocked from Orion and docked into LM, their crew performed several inspections, checks and tests prior to starting their descent toward lunar surface.
Landers in space are complex systems of controls, sensors and computers. One of the key components is the CSM’s navigation computer which tracks their position on the Moon by measuring distance from Earth using a directional gyro and an odometer; additionally it uses a Sun-shadow device to calculate manual heading based on where Sun appears in the sky.
Young and Duke traveled to Stone Mountain, a volcano believed to be part of the Descartes Formation, with plans to sample its volcanic components as well as those in North Ray, an unexplored crater nearby that may help disprove prevailing theories that claimed lunar highlands were formed through conventional volcanic activity.
After approximately four hours on EVA, they returned to Casper in time to meet with ALSEP – Lunar Surface Experiments Package, also known as LSEP. Housed within the Scientific Instrument Module bay in Casper, ALSEP consisted of instruments and cameras intended to collect data on lunar environment while handheld Hasselblad 70mm still and Mauer 16mm motion cameras allowed crew members to record their lunar adventures.
The crew returned to their LM the next day and, following a series of checks and tests, began their return home. Mattingly conducted an 84-minute spacewalk outside to retrieve film cassettes recorded by panoramic and mapping cameras; during which time his wedding ring got lost in space; only upon reaching his LM was it found again.