Apollo 16 – A Golden Anniversary
On the 50th anniversary of Apollo 16, we celebrate the journey and legacy of the twentieth century’s penultimate mission to the Moon.
A substantial sum of money and huge effort went into making the first crewed mission to the Moon in 1969 possible but by the autumn of 1970 further planned missions of the Apollo Program were axed due to waning public interest and lack of funding. Apollo 17 was marked as the final mission to launch. As such, Apollo 16 became one of the last chances for human exploration of the Moon to be pushed to its limits.
Apollo 16 Commander John Young was a veteran of three previous spaceflights including flying as command module pilot for Apollo 10 – the ‘dummy run’ for Apollo 11’s landing on the Moon. Originally joining NASA’s astronaut corps as part of the Gemini Program (America’s second human spaceflight Program), Young’s first mission was with Gus Grissom on Gemini 3 – they conducted America’s first two-person crewed Earth-orbiting spaceflight. Although greeted with jubilant celebrations upon returning to Earth, Young also received a stiff telling-off for smuggling a contraband corned beef sandwich aboard the spacecraft!
Thomas “Ken” Mattingly was Apollo’s 16’s Command Module Pilot and the mission became his first spaceflight. He was scheduled to fly on the ill-fated Apollo 13 mission, but just three days before launch he was replaced by Jack Swigert, having been exposed to German Measles (which he didn’t actually contract). Although admittedly disappointed, the feeling quickly dissipated when the oxygen tank explosion on Apollo 13 occurred two days into its mission. Mattingly remained at NASA after the Apollo program and was able to fly on America’s next major space vehicle, the Space Shuttle. Along with John Young, he is the only person to have flown to the Moon and conducted an orbital mission on a Space Shuttle.
Charlie Duke was the Lunar Module Pilot for Apollo 16, and to date remains the youngest person to have walked on the Moon, aged 36. He served as CAPCOM for Apollo 11 and it’s his familiar southern accent we’ve heard being played marking the moment that astronauts touched down on the Moon for the very first time: “Roger, Twank…Tranquillity, we copy you on the ground. You got a bunch of guys about to turn blue. We’re breathing again. Thanks a lot!” Having retired in 1976, Apollo 16 was Duke’s only spaceflight mission.
The Mission Patch and Spacecraft
Each Apollo mission had its own mission patch, designed with input from the crew.
Young, Mattingly, and Duke wanted to evoke patriotism and teamwork in their patch. Alike to some of the other missions, the crew also championed having their names and mission number on it too. Find out more in our mission patch blog.
Crew were also allowed to name the modules of their spacecraft – names that would be used as call signs. After Apollo 10 astronauts chose Charlie Brown and Snoopy for their spacecraft, NASA insisted on more appropriate names. Whilst Young and Duke went with ‘Orion’ for the Apollo 16 Lunar Module (something that would connect to the stars), Mattingly chose ‘Casper’ the friendly ghost for the Command and Service module claiming that “there are enough serious things in this flight, so I picked a non-serious name”.
All Apollo astronauts (excluding Jack Schmidt of Apollo 17) were trained test pilots and not geologists who would be experts in analysing rocks. Because the biggest goal of the Apollo Program following landing on the Moon was exploring the lunar geology, NASA enlisted the help of local geologists to provide lessons to the astronauts. In the Marathon Basin of West Texas, NASA turned to Jackson School of Geosciences, Professor William Muehlberger who trained astronauts to recognise geological features on Earth rocks, so they could apply their learning on the Moon.
During the Apollo 16 mission, Duke collected the biggest rock ever brought back from the Moon (11.7kg) – named “Big Muley” by the astronauts in honour of their teacher Muehlberger.
They had hoped this rock from their landing region in the lunar highlands region would be volcanic, but it turned out to be a breccia – broken fragments of minerals or rocks created by meteorites bombarding the Moon earlier in its history.
From their training, the astronauts knew that it wasn’t a case of them being unable to identify and find volcanic rock but was more a case of there being a lack of volcanic rock present. In time, this mission helped to disprove the then current theory that the lunar highlands were created by conventional volcanic activity.
Journey to the Moon
Apollo 16 was destined for the Descartes highlands – it was the first-time crew landed in the central lunar highlands as opposed to previously explored “mare” and the areas directly surrounding these dark grey regions on the Moon.
After arriving in lunar orbit, Young and Duke entered the lunar module and undocked with the command and service module separating themselves from Mattingly. It was then realised that there was a problem with the command and service modules’ propulsion system. Under such circumstances, with the lunar module still in a position to redock, rules stipulated that the landing should be aborted so that the lunar module’s engines could be used for the return trip to Earth. Instead, the crew maintained their positions close enough to each other and following several hours of analysis, it was deemed that the problem could be worked around, and the lunar landing could proceed.
By the time Young and Duke got going they were six hours behind schedule. To give the astronauts enough time for sleep and rejuvenation, the final moonwalk was trimmed by two hours. And for the return journey the crew would spend one less day in lunar orbit before heading back to Earth, allowing time to deal with further problems if they developed.
On the Moon
Despite landing over 250m from their target lading site, having the Lunar Roving Vehicle made this a trivial issue. During their stay on the Moon, Young and Duke covered 26.7km using the Moon buggy and collected samples from eleven different sites, bagging 95 kilograms to bring back to Earth.
The final three missions of the Apollo Program (15,16 and 17) were planned to conduct extensive science studies. And whilst the first four lunar landings had focused on the lunar plains or “maria”, Apollo 16 was the first to explore the lunar highlands. We now understand that the highlands are older than the dark plains which formed later when molten rock from the Moon’s interior seeped to the surface to flood low lying areas. It was the geological training and sample gathering of the Apollo 16 astronauts that gave scientists a better understanding of how the lunar highlands formed.
Whilst busy working, Apollo 16 astronauts also had to deal with the effects of their strict diet. After Apollo 15 astronaut James Irwin suffered from irregular heart rhythms (thought to be from a lack of potassium), doctors increased the amount of citrus in the Apollo 16 astronauts’ meals. Trapped in their spacesuits conducting extra-vehicular activity (EVA) on the lunar surface, Young expressed to Duke (and inadvertently mission control along with the world) his flatulence issues: “I have the farts, again… I don’t know what the hell gives them to me… I think it’s acid stomach, I really do… I haven’t eaten this much citrus fruit in 20 years… [and after this mission] I ain’t never eating any more.”
On the return journey, Ken Mattingly conducted a trans-Earth spacewalk. He spent 83 minutes on his EVA retrieving film cassettes from the exterior of the spacecraft (the command and service module) which had recordings taken by the panoramic and mapping cameras. And perhaps the most remarkable thing occurred during the spacewalk with Charlie Duke assisting him from the open hatch – the incident of a wedding ring almost lost in space forever!
Check out Charlie Duke recounting the event in the video below, from his visit to the National Space Centre on 21 November 2009.
About the author: Dhara Patel is a Space Expert at the National Space Centre.