Apollo 16, the tenth manned mission in AmericanApollo space program, was the fifth mission to land on the Moon and the first to land in a highlands area. Launched on April 16, 1972, it was a J-class mission, featuring the program's second Lunar Roving Vehicle; and brought back 94.7 kg of lunar samples.
It included three lunar EVAs: 7.2 hours, 7.4 hours, 5.7 hours and one trans-earth EVA of 1.4 hours. Despite a malfunction in the Command Module which almost aborted the lunar landing, Apollo 16's lunar module landed successfully in the Descartes Highlands on April 21. Commander John W. Young and Lunar Module Pilot Charles Duke spent nearly three days on the lunar surface while Command Module Pilot Ken Mattingly orbited the Moon.
A subsatellite was released from the Service Module while in lunar orbit to carry out experiments on magnetic fields and solar particles (the first subsatellite had been released from Apollo 15).
The crew splashed down in the Pacific Ocean on April 27.
Young and Duke served as the backup crew for Apollo 13; Mattingly was slated to be the Apollo 13 command module pilot until being pulled from the mission due to his exposure to rubella through Duke.
Although not officially announced, the original backup crew consisted of Fred Haise (CDR), William R. Pogue (CMP) and Gerald Carr (LMP) who were targeted for the prime crew assignment on Apollo 19.[2] However, after the widely-expected cancellations of Apollo 18 and Apollo 19 were finalized in September 1970 it meant that this crew would not rotate to a lunar mission as planned. Subsequently, Roosa and Mitchell were recycled to serve as members of the backup crew after returning from Apollo 14, while Pogue and Carr were re-assigned to the Skylab program where they later flew on Skylab 4.
Mattingly's EVA was only the second trans-earth EVA ever and was used to bring in film from exterior cameras and conduct an experiment on microbial survival.
The splashdown point was just south of the equator in the Pacific Ocean at 0 deg 43 min S, 156 deg 13 min W, 215 miles (346 km) southeast of Christmas Island (Kiritimati) and 5 km (3.1 mi) from the recovery ship USS Ticonderoga.
Mission highlights
A Saturn V rocket launches Apollo 16.
The original launch date in March 1971 was scrubbed well in advance due to an issue with a fuel tank supplying the RCS on the command module. The location of the problem forced a rollback to the VAB on January 27, 1971. The stack was returned after repairs well before the final countdown was initiated.[3]
A malfunction in a backup yaw gimbal servo loop in the main propulsion system of the CSM Casper caused concerns about firing the engine to adjust the CSM's lunar orbit, and nearly caused the Moon landing to be aborted. After a delayed first landing attempt, it was determined that the malfunction presented relatively little risk, and Young and Duke (who were already undocked, and flying LM Orion when the problem occurred) were permitted to land on the Moon.
John Young jumps while saluting the American flag.
Young and Duke spent three days exploring the Descartes highland region, while Mattingly circled overhead in Casper. This was the only one of the six Apollo landings to target the lunar highlands. On the first day of lunar surface operations, news was relayed to them that the House of Representatives had approved the Space Shuttle program. Young stated that it was needed.[4]
The astronauts discovered that what was thought to have been a region of volcanism was actually a region full of impact-formed rocks (breccias). Their collection of returned specimens included a 25-pound (11 kg) chunk that was the largest single rock returned by the Apollo astronauts[5] (nicknamed "Big Muley" after Bill Muehlberger, principal investigator for the mission's geology activities[6]). The scientific results of Apollo 16 caused planetary geologists to revise previous interpretations of the lunar highlands, concluding that meteorite impacts were the dominant agent in shaping the Moon's ancient surfaces.
Young and Duke set up their Apollo Lunar Surface Experiments Package (ALSEP), which included an experiment to measure heat flow between two probes they were to insert into holes drilled in the surface. Young, however, accidentally got one foot tangled up in the cable to one of the probes, detaching it and rendering the experiment useless.
The astronauts also conducted performance tests with the lunar rover, Young at one time getting up to a top speed of 11 miles per hour (18 kilometers per hour), which still stands as the record speed for any wheeled vehicle on the Moon (listed as such in the Guinness Book of Records).
Apollo 16 was originally scheduled for splashdown at 3:30 pm EST on April 28. The mission was shortened by a day (reducing the time in orbit around the Moon after the LM left the Moon and docked with the CSM) because of the problems with the command module prior to landing. As Duke described on the Apollo Lunar Surface Journal website: "The more you waited up there - if you did have a problem - the less time you had to think of something brilliant to fix it. They got a little nervous and brought us home a day early, I think, just to make sure we could have some ample time to fix any problems."[7] There were no problems encountered during the return flight.
The aircraft carrier USS Ticonderoga delivered the Apollo 16 command module to the North Island Naval Air Station, near San Diego, California on Friday, May 5, 1972. On Monday, May 8, 1972, ground service equipment being used to empty the residual toxic RCS fuel in the command module tanks, exploded in a Naval Air Station hangar. A total of 46 people were sent to the hospital for 24 to 48 hours observation, most suffering from inhalation of toxic fumes. Most seriously injured was a technician who suffered a fractured kneecap when the GSE cart overturned on him. A hole was blown in the NAS hangar roof 250 feet above, and about 40 windows in the hangar were shattered. The command module suffered a three-inch gash in one panel.[8][9][10]
Subsatellite
The lunar subsatellite (PFS-2), virtually identical to one released during Apollo 15, was a 78 cm x 36 cm hexagonal cylinder weighing 36.3 kg and three 1.5 m booms. Released from the Service Module's Scientific Instrument Module (SIM) bay on April 24, 1972 at 21:56:09 UTC, the subsatellite's mission was to measure plasma, energetic particle intensities and the lunar magnetic fields. The craft was deployed by a spring action, which generated a relative velocity of around 1.2 m/s and a spin of 120 rpm. It returned data from 24 April to 29 May 1972 with an orbital period of around 120 minutes. It was deployed into a sub-optimal inclination and the orbit decayed earlier than anticipated, with impact occurring after 34 days and 425 revolutions.[11]
Spacecraft locations
The Apollo 16 capsule is on display, with the parachute hanging above it.
The Apollo 16 command module Casper is on display at the U.S. Space & Rocket Center in Huntsville, Alabama. The lunar module ascent stage separated 24 April 1972 but a loss of attitude control rendered it out of control. It orbited the Moon for about a year. Its impact site on the Moon is unknown.
Duke donated some flown items, including a lunar map, to Kennesaw State University in Kennesaw, Georgia. He left two items on the Moon, both of which he photographed. The most famous is a plastic-encased photo portrait of his family (NASA Photo AS16-117-18841). The reverse of the photo is signed by Duke's family and bears this message: "This is the family of Astronaut Duke from Planet Earth. Landed on the Moon, April 1972." The other item was a commemorative medal issued by the United States Air Force, which was celebrating its 25th anniversary in 1972. He took two medals, leaving one on the Moon and donating the other to the Wright-Patterson Air Force Base museum.[12]
Mission insignia
Robbins Medallion from Apollo 16.
The circular emblem featured an eagle with wings outstretched, perched atop a red, white and blue shield, over a lunar surface. The vector symbol from the NASA logo was placed on top of the shield, and then across the shield were written the words APOLLO 16. The artwork was bordered in white, with a blue band carrying 16 stars and the crew names, outlined by a gold border. The insignia was designed by NASA artist Barbara Matelski.
Quotes
"I mean, I haven't eaten this much citrus fruit in 20 years! And I'll tell you one thing, in another 12 fucking days, I ain't never eating any more."—John Young in an air-to-ground transmission, reacting to stomach problems caused by drinking potassium-enriched orange juice (to prevent an electrolyte deficiency identified in the crew of Apollo 15). He was unaware that his microphone was still transmitting after a recent conversation with Mission Control.[13][14]
^Swanson, Glen E., ed. 1999. "'Before This Decade is Out....': Personal Reflections on the Apollo Program [sp4223]," Washington, D.C.: NASA, chapter 11. http://history.nasa.gov/SP-4223/ch11.htm. Retrieved August 30, 2009.
^Chaikin, Andrew: "A Man on the Moon: The Voyages of the Apollo Astronauts", page 476. Penguin, 1998
