Skip to comments.40 Years Ago This Month: Apollo 16 (long article)
Posted on 04/10/2012 11:19:09 AM PDT by chimera
Apollo 16, the penultimate lunar landing mission, began on April 16, 1972, 40 years ago this month. The second of the J missions, Apollo 16, like Apollo 15 before it, carried an uprated lunar module, a SIM bay in the CM/SM, and an electric-powered lunar rover. Gemini and Apollo veteran John Young commanded this historic mission.
Lunar geologists were anxious to target an Apollo mission for the lunar highlands. You can easily see them if you look at the moon when it is in a phase from waxing or waning gibbous to full. The brighter surface areas are the highlands regions, as opposed to maria, which are the darker areas. It was through that the highland areas might have the elusive volcanic rocks which were coveted by geologists and are valuable in understanding the formation of rocks in the lunar environment. Since the highlands were obviously not flooded by the darker maria substance, it was thought that the samples found there might be among the oldest on the lunar surface.
NASA mission planners were gaining confidence in the ability of crewmen to make precise landings even in fairly rough lunar terrain. Several candidate highlands sites were considered. The scientists finally settled on a patch of hills near the crater Descartes, called the Caley plains, or Caley-Descartes formation. Here is a picture of the landing site, which clearly shows the rugged terrain targeted for this mission:
The bright spot near the center is the crater complex called South Ray crater. The landing site is just north, or above South Ray. The mountainous, hummocky lands to the right of South Ray are the Descartes Mountains, with Stone Mountain being the prominent feature.
Apollo 16 liftoff occurred at 12:54 PM EST on April 16th 1972 from launch complex 39A of the KSC. Like Apollo 15, the Saturn V for Apollo 16 had uprated thrust, about 7.6 million pounds, to lift the heavier payload. Here is a lovely picture of the launch, framed by the lush Florida landscape of Cape Canaveral:
In addition to Mission Commander Young, Apollo 16 also carried Command Module Pilot Thomas Ken Mattingly and Lunar Module Pilot Charles (Charlie) Duke. Readers will recall that Ken Mattingly was the hard-luck scratch from the ill-fated Apollo 13 mission in April 1970. Mattingly and Jack Swigert essentially swapped seats when Mattingly was bumped from the 13 mission because of exposure to measles, which he never contracted. As it turned out, it was good luck for Mattingly that he got to ride a successful mission, although he always expressed the desire that he could have ridden on his original assignment with the crewmates he had trained so long with.
The Apollo 16 mission had a minor, non-critical glitch on the voyage out to the moon, when the guidance system on the spent S-IVB stage failed and controllers essentially lost track of the trajectory, which was intended, as with earlier missions, to hit the moon and register on the seismometers left by earlier crews. As it turned out, the S-IVB stage, with its heavy engine compartment, did impact the moon, about 200 km off-target. But the impact was recorded on all three still-functional seismic stations.
Like Apollo 15, the CM/SM of Apollo 16 had a SIM bay stuffed with sophisticated scientific instruments. Once in lunar orbit, CM pilot Mattingly got busy operating these instruments which provided a wealth of information on lunar gravity, high-resolution surface photography, and chemical analysis from orbit using things like spectrophotometry and radar analysis of the surface. This one was benefit Mattingly had from being bumped from Apollo 13, he had a lot more to do when in lunar orbit by himself. Another was doing the second space walk in cislunar space (more on that later).
Once separated, the LM and CM assumed their radio call signs, Orion for the LM and Casper for the CM. The latter was a bit whimsical as a play on the familiar childrens cartoon character of the friendly ghost. CM pilot Mattingly named his ship after a friendly ghost because he thought the images of astronauts on the lunar surface in TV transmissions (at least the early ones, like Apollo 11) has a ghostly appearance, being kind of fuzzy, bloomy, and taxing the exposure limits of the cameras when they were in full sunlight. Orion, of course, refers to the constellation of the same name, which is prominent in northern hemisphere skies from late Fall to early spring. It in turn is named after the powerful hunter of Greek mythology. LM Orion carried the first ultraviolet astronomical telescope to the lunar surface which would take the first such images of stars from that viewpoint.
It was at this point that the troubles began. First, the LM experienced a potentially dangerous pressure increase in the RCS propellant systems. This was solved when one of the controllers at MCS in the Houston center suggested shunting the excess propellant into the LM ascent engine propellant tanks. This was clever in that they didnt lose any propellant volume, but were able to reduce pressure to acceptable limits.
The real potential show-stopper occurred just before the CM/SM fired the SPS engine to regain a circular lunar orbit. Like the previous two missions, the SPS was used to drop the LM/CM combination into a lower orbit prior to starting the LM descent, to save LM fuel for the landing. CM pilot Mattingly was required to test the SPS engine gimbaling systems prior to the engine burn, and when he tested the backup system he noticed a very strong vibration, almost a shaking of the entire spacecraft. He knew immediately that this was symptomatic of an unstable gimbal controller. All of this was reported to both Mission Commander Young in the LM and controllers on the ground. The immediate response from MCS was to wave-off the landing attempt, at least for one more orbit, while they mulled things over.
Controllers were understandably concerned. Mission rules said the SPS engine control system had to be functional in both primary and backup control modes or its use was precluded. Although the primary control system appeared functional, the questionable condition of the backup system made controller nervous. This was a result of the Apollo 13 experience, where use of the LM in lifeboat mode was the only thing that saved the lives of the crew. Once the LM was used for the landing, the lifeboat option was no longer available. At that point, everything depended on the CM/SM/SPS. It simply had to work, or the crew could be in grave danger. Mattingly was resigned to having the landing called off and the mission deemed a failure. He was certain the controller on the ground would order a rendezvous with the LM and use the LM descent engine to push them out of lunar orbit and the trip home.
The engineers at Houston conferred with the manufacturer of the SPS, which was the Rocketdyne division of North American Rockwell. After reviewing the telemetry data, the engineers convinced themselves that even if the engine vibrated during firing, it would be acceptably controllable for use in lunar orbit operations and for the return trip. They had to work fast, because the sun was rising over the Descartes landing site and another lunar orbit would result in unacceptable lighting conditions for a landing.
So, to the amazement and relief of the crew, the word was passed up, Go for landing. Young and Duke would have their mission on the surface. Mattingly was able to maneuver the CM/SM to a higher orbit without incident. The lunar landing then proceeded without incident. LM Orion touched down on the lunar surface at 9:24 p.m. EST on April 20, 1972. The rough surface caused the lander to tilt noticeably after landing, with one footpad slightly over the edge of a worn crater.
As the second J mission, an extended lunar surface stay was planned, which eventually totaled a little over 71 hours. The area was rich in geologic samples, and also quite spectacular for scenery, with the rolling lunar highlands surrounding the site, dominated by the impressive bulk of Stone Mountain. Here is the famous picture of John Young leaping off of the lunar surface while saluting the American flag:
Stone Mountain is in the background.
TV was a bit of a problem on Apollo 16. The steerable antenna on the LM was acting flaky and could not be used for transmission of the initial steps on the lunar surface. Only when the lunar rover was deployed and its camera turned on, as well as the s-band erectable antenna set up on the surface did viewers get their first look at operations on the surface.
The most disappointing moment of the three EVAs occurred when setting up the surface experiments. One experiment from Apollo 15 that had caused such consternation on that mission was measurement of the heat flow through the lunar crust. The Apollo 15 LM crew had no end of problems with the drill used to remove soil cores and place the heat flow probes. The heat flow experiment on Apollo 15 never did provide good quality data as a result of these problems. NASA had spent a lot of time and effort re-working the drill and evidently had solved the problem for Apollo 16. Indeed, when LM Pilot Charlie Duke began drilling the holes and placing the probes, he noted how well the improved drill was working. A short time later, the cables connecting the heat flow experiment to the central experiment station became tangled around Youngs feet. A few more steps and he pulled the cables, out, irreparably damaging them and effectively ruining the experiment. Dukes reaction to the accident was Well, Im wasting my time , referring to placing the heat flow probes.
It wasnt Youngs fault. Anyone who has had to work with ribbon cables knows that they are balky things that tend to have a memory. The cables on the Apollo ALSEP package were even bigger and clumsier than the ones we have today in PCs and the like. So when they were bundled up in the LM storage bays and then unfurled on the lunar surface, they tended to tangle and bunch up. Young, in his bulky pressure suit, could not easily see his feet, and never felt the cables tangle. It was thought for a time that the cable might be repairable, but time pressures eventually forced it to be abandoned.
The geology traverses had better luck. Young and Duke were able to explore a variety of craters and landforms. Like on Apollo 15, they were able to ascend the slope of an impressive lunar mountain, in this case Stone Mountain. Unlike the somewhat bland slopes of the Apennine Mountains on Apollo 15, the mountains of the Apollo 16 site were littered with the debris of the nearby impact craters. Most of the samples collected by the explorers were breccias, which are rocks formed from the fusing of other rocks by the heat and pressure of meteor impacts. A few samples were rhyolite and anorthosite from the ancient lunar crust. Here is a view from the side of Stone Mountain:
Some of the breccias were quite large, the size of boulders. Here is astronaut Duke near a large one called Shadow Rock, which is about 10 feet high. The soil under the rocks overhang was thought to have been permanently in shadow, and so was of interest to geologists.
A total of three EVAs were conducted, with a total outside time of a little over 20 hours. About 211 lbs. of rock samples were collected. LM Orion left the moon at 8:26 p.m. EST on April 23, 1972. The lunar rover TV camera captured pictures of the LM liftoff as well as the descent stage left behind:
On the journey back to Earth, Ken Mattingly got to perform the second deep-space EVA, which lasted considerably longer than the one performed on Apollo 15. Here is a photo of Mattingly going about his business surrounded by the utter blackness of interplanetary space:
Mattingly has obviously traded helmets with John Young as his EVA suit shows the red stripe normally denoting the mission commander. The mission ended without incident on April 27, 1972, with a landing in the Pacific recovery zone.
I find the mission patch of Apollo 16 particularly inspiring:
I like it because it shows the symbol of the United States, the bald eagle, perched on a red, white, and blue shield. Together, these represent the people of the United States. The stylized NASA wings are rendered in gold, and all of them are overlaying the lunar surface, indicating the era of lunar exploration. The image is surrounded with 16 stars, indicating the mission number, and the names of the crewman, which always list, left to right, the mission commander, the CM pilot, and the LM pilot, the traditional 1-2-3 number crewmen for the Apollo missions.
Apollo 16 provided perhaps the most surprising result of all the missions in terms of lunar geology. The scientists were forced to re-think their hypotheses as to the formation of the lunar highlands. No volcanic rocks were found. Almost everything collected was impact debris. It is now thought that the lunar highlands were formed from ejecta resulting from the impacts that formed the maria region. One can imagine a wave of debris being pushed out away from the impact zone, forcing the shattered crust and other debris to pile up into the lunar highland regions. Over time, the rounded shapes of the mountains formed not from weathering as on Earth, but the constant rain of micrometeoroids.
The crew of Apollo 16 was an interesting blend of interservice rivalry and rookie-veteran combination. Mission Commander John Watts Young seemed to have a penchant for being on historic missions. He was the co-pilot for Gus Grissom on the very first Gemini mission, Gemini 3. Young later commanded his own mission, Gemini 10, which set a then-record altitude of almost 500 miles above the Earth, and was the first manned mission to venture into the region of the Van Allen radiation belts that surround the Earth, and showed that radiation exposure at high altitudes would not be a problem for the flights planned in the future. During the Apollo program, Young piloted the CM for the Apollo 10 mission, which was the first to test the LM in lunar orbit. He bided his time and eventually won the commanders position for Apollo 16, the first mission to the lunar highlands. His love of spaceflight induced him to stay with NASA after the end of the Apollo program, which paid off when he became the very first commander of a space shuttle mission, which was the historic STS-1 flight of Columbia in 1981. He later commanded Columbia on the STS-9 flight in 1983, which was the flight of the first Spacelab module. Prior to his joining NASA, John Young was a naval aviator and served during the Korean War. He became a naval test pilot and was assigned to the Navys Naval Air Test Center for three years. He retired from the military in 1976 with the rank of Navy Captain. Young stayed on at NASA for 42 years, and retired on December 31, 2004 at 74 years old. A native of San Francisco, he lives today in the Houston area. Certainly a very long and productive, distinguished career of service to his country.
Command Module Pilot Thomas Kenneth Mattingly is a native of Chicago, but went to school in Hialeah, Florida. Ken Mattingly joined the Navy as an Ensign after gr5aduating from Auburn University, and became a naval aviator. He was on active duty in the early 1960s. He joined NASA in 1966 and was selected as the CMP for the ill-fated Apollo 13 flight, but was bumped at the last minute because of exposure to German measles. He was re-assigned to Jack Swigarts seat on Apollo 16, which turned out to be a fortunate circumstance for Mattingly as he was able to serve on a completed mission. Ken Mattingly commanded both the STS-4 and STS-51-C missions during the shuttle program. STS-4 was the final test flight for the shuttle and afterwards NASA declared it operational. STS-51-C was the first exclusively defense department mission. Mattingly retired from both NASA and the Navy in 1989, attaining the rank of Admiral (two-star). After leaving NASA, Ken Mattingly worked in the aeronautics industry and lives today in Virginia. Here is one of my favorite pictures, which shows astronaut Mattingly with the Best.President.Ever and Best.First.Lady.Ever:
Lunar Module Pilot Charles Moss Charlie Duke Jr. is familiar to Apollo Program aficionados as the Capcom for the Apollo 11 lunar landing. His famous pronouncement of the successful landing We copy you on the ground. Youve got a bunch of guys about to turn blue. in his Carolinian drawl is well-remembered by those of us who watched it happen live on TV. Duke is a graduate of the Naval Academy but opted for a commission in the Air Force, where he became a fighter pilot, doing foreign duty at Ramstein AFB in what was then West Germany, and later serving as an Air Force test pilot. He joined NASA and was the backup LMP for Apollo 13, which led to his assigned on the prime crew of Apollo 16, which was to be his only trip into space. Charlie Duke became a very spiritual man after his lunar flight, and continues his Christian witness today in ministering to prisoners. He retired from the Air Force with the rank of Brigadier General. A native of Charlotte, NC, Charlie Duke today lives in Texas.
The Apollo 16 mission led to a major discovery about the origin of the lunar highlands, a fact that had remained hidden from man from the time he first gazed up at the silvery orb that ruled the night skies of his world. Perhaps thinking of this, the renowned lunar geologist Farouk El Baz wrote on a blackboard as the Apollo 16 mission was concluding a quote from the philosopher Rene Descartes, namesake of the just-visited Descartes highlands:
"There is nothing so removed from us to be beyond our reach or so hidden that we cannot discover.
When the U.S used to do stuff.
Do you have this on a blog? I would like the link. Its worth saving.
Tomorrow is the 42nd anniversary of the launch of Apollo 13. The common thread between Apollo 13 and Apollo 16 is Thomas Kenneth Mattingly ii. He was to be on 13 but was replaced due to the possibility of coming down with measles during the flight. As is history, he made it on 16.
Another curious tie to a future program was that as John Young and Chalres duke wer in the midst of the first moonwalk, Houton’s CAPCOM called up and told them that the appropriations for the space shuttle had been approved in congress. Nine years later, Young was in the left seat of Columbia on the very first space shuttle flight.
Apollo 16 had one day trimmed from its original plan due to a problem with the service module engine after LM undocking. Too much time was used to work the problem so it was decided to trim the mission length. They still got everything done they had to do on the lunar surface. 16 was a hugely successful flight.
One other thing. At liftoff from the lunar surface, the ascent stage engine packed enough power to force the decent stage to settle a little lower than prior to ignition. In the Apollo Lunar Surface Journal, there is a two-frame animation that shows that. Pretty cool to see.
Swapping custom made, fitted helmets isn't enough - it also has to be swapped with the mission commander's stripe, for use in an actual EVA.
LOL, nothing to see here, move along.
And DON'T ask why some crater edges shine as brightly as... glass... while all the others are dull.
Just don't, okay?
What are you suggesting?
FYI the oxygen purge system (OPS) and the commander's visor and sunshield were saved and were used by the CM pilot during the spacewalk to retrieve the film canisters. The CM pilot was not issued one of his own since he would not be performing surface activities. Issuing a third would be wasteful for weight when they already had two usable OPSs. The OPS had an oxygen supply and a regulator system. The second OPS was also saved for the LMP stand-up EVA at the same time. During the cabin purge for the cislunar EVA, the commander was on suit pressure directly from the CM LSS. Photos of Apollo 17's discarded PLSS packs show there was no OPS attached.
I think it was the same for all the J missions. The commanders sunshade/visor was saved with the OPS system. I think the OPS was discarded after the spacewalk.
I see the source of your confusion. My original post confused the terminology. My bad. They did not swap helmuts, only visor assemblies. It’s important to know that it is just a visor assembly, it has no pressure seal at all. It goes over the bubble/fishbowl helmet you see the astronauts wear when they walked out to the bus taking them to the pad. That part of the EVA garment was fairly flexible and designed to fit a variety of sized helmets, just like you can get sunshades to use on the beach that fit a variety of different head sizes.
Back when the USA was the USA not some vagrant handout society
Thanks chimera. >An “extra, extra” ping to the APoD list members.
One of the coolest things you’ll ever see.
Apollo 11 Ultra Slow Motion 16mm HD launch
And yes, this was his description of a dream he had in 1971, before he actually went to the Moon. :') He also said, "why would have have faked it NINE TIMES?!?"Stephen Baxter interviews Charlie DukeJohn and I were driving the Rover to the north, up to North Ray Crater, and as we came over one of the ridges there was a set of tracks out in front of us going east- west. And so we got excited, told Houston, and they said 'Well, follow the tracks.' You could tell by the tread marks that the vehicle was going to the east. So we turned right, to the east. And towards the eastern end of the valley we come upon this car, as we come over the ridge and there's this car which looked very similar to the Lunar Rover and there was two figures in it. So we radioed that we'd found this car, and we start top describe it, and they start to get excited, we're excited. So we turned the car, pointed and turned the TV on, and I ran over to the passenger side and I pulled up the visor and I was looking at myself... The other fellow looked like John.
August 12th, 2000
Hey wait a minute, are you one of those weirdos who thing we actually landed on the Moon?!? ;’) Thanks cc.
Thanks for the article. All of these years I always thought how difficult it was for us to actually land someone on the moon. After reading this article, I’m thinking the hardest part was getting them off the moon and back home!
“Yeah that vibration? We’re pretty sure it will be okay - go ahead and drop down to the moon.”
“You hit a little too hard and are uneven? You think WHAT might be bent? No - you don’t have a repair kit for that. But we’re pretty sure it won’t be a problem on takeoff.”
The albedo of lunar craters varies depending on their age. In the case of South Ray crater, near the Apollo 16 landing site, the age of this crater is about 2 million years, which is a very young crater as lunar impacts go. It has a very bright "halo" and streaks, or rays, extending outward. As lunar craters age, the ejecta material reflects less light because of changes in the crystals that make up their substance. Reflectivity is diminished by the cumulative effects of micro-meteoroid impacts, and also radiation-induced darkening of quartz crystals.
This was one of the differences noted in the returned samples that also indicates their lunar origin. We don't see as pronounced process in terrestrial samples because the cosmic ray flux at the surface is modified by the Earth's atmosphere. In the airless lunar environment, those crystals are seeing an undiminished cosmic ray flux, and that changes the radiolytic effects quite dramatically.
“I don’t think I have the guts to do it myself.”
What got me was that all three were so excited that the mission wasn’t scrubbed in spite of the possible problem. Of course my reference is the mundane things in my life (”I don’t think we should drive to the movie with the car the way it is”). After the years of training and anticipation to be on THE MOON the risk vs. reward ratio is a whole lot different.
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