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Apollo 16
Launched: 16 April 1972 UT 17:54:00
(12:54:00 p.m. EST)
Landed on Moon: 21 April 1972 UT 02:23:35 (20 April 09:23:35 p.m. EST)
Landing Site: Descartes (8.97 S, 15.50 E)
Returned to Earth: 27 April 1972 UT 19:45:05 (02:45:05 p.m. EST)
John W. Young, commander
Thomas K. Mattingly II, command module pilot
Charles M. Duke, Jr., lunar module pilot
Apollo 16 was the fifth mission
in which humans walked on the lunar surface and returned to Earth. On 21 April
1972 two astronauts (Apollo 16 Commander John W. Young and LM pilot Charles M.
Duke, Jr.) landed in the Descartes region of the Moon in the Lunar Module (LM)
while the Command and Service Module (CSM) (with CM pilot Thomas K. Mattingly,
II) continued in lunar orbit. During their stay on the Moon, the astronauts set
up scientific experiments, took photographs, and collected lunar samples. The LM
took off from the Moon on 24 April and the astronauts returned to Earth on 27
April.
Mission Profile
Apollo 16 launched on 16 April
1972 at 17:54:00 (12:54:00 p.m. EST) on Saturn V SA-511 from Pad 39A at Kennedy
Space Center. (The launch was postponed from the originally scheduled date,
March 17, because of a docking ring jettison malfunction.) The spacecraft
entered Earth parking orbit at 18:05:56 UT and translunar injection took place
at 20:27:37 UT. The CSM and S-IVB stage separated at 20:58:59 UT and CSM-LM
docking was achieved at 21:15:53 UT. The S-IVB stage was released into a lunar
impact trajectory, but due to an earlier problem with the auxiliary propulsion
system (APS) helium regulators, which resulted in continuous venting and loss of
helium, the second APS burn could not be made. Tracking of the S-IVB was lost on
17 April at 21:03 UT due to a transponder failure. (The S-IVB stage impacted the
Moon on 19 April at 21:02:04 UT at 1.3 N, 23.8 W with a velocity of 2.5 to 2.6
km/s at a 79 degree angle from the horizontal, as estimated from the Apollo 12,
14 and 16 seismic station data.) A mid-course correction was performed at
00:33:01 UT on 18 April. During translunar coast a CSM navigation problem was
discovered in which a false indication would cause loss of inertial reference,
this was solved by a real-time change in the computer program. The SIM door was
jettisoned on 19 April at 15:57:00 UT and lunar orbit insertion took place at
20:22:28 UT. Two revolutions later the orbit was lowered to one with a perilune
of 20 km.
At 15:24 UT on 20 April Young and
Duke entered the LM. The LM separated from the CSM at 18:08:00 UT, but the LM
descent was delayed almost 6 hours due to a malfunction in the yaw gimbal servo
loop on the CSM which caused oscillations in the service propulsion system (SPS).
Engineers determined that the problem would not seriously affect CSM steering
and the miision was allowed to continue with the LM descent. The LM landed at
02:23:35 UT on 21 April in the Descartes highland region just north of the
crater Dolland at 9.0 S, 15.5 E. Young and Duke made three moonwalk EVAs
totaling 20 hours, 14 minutes. During this time they covered 27 km using the
Lunar Roving Vehicle, collected 94.7 kg of rock and soil samples, took
photographs, and set up the ALSEP and other scientific experiments. Other
experiments were also performed from orbit in the CSM during this time.
The LM lifted off from the Moon
at 01:25:48 UT on 24 April after 71 hours, 2 minutes on the lunar surface. After
the LM docked with the CSM at 03:35:18 UT the lunar samples and other equipment
were transferred from the LM and the LM was jettisoned at 20:54:12 UT on 24
April. The LM began tumbling, apparently due to an open circuit breaker in the
guidance and navigation system. As a result the planned deorbit and lunar impact
could not be attempted. The LM remained in lunar orbit with an estimated
lifetime of one year. The instrument boom which carried the orbital mass
spectrometer would not retract and was jettisoned. Because of earlier problems
with the SPS yaw gimbal servo loop the mission was shortened by one day. The
orbital shaping maneuver was cancelled, and the subsatellite was spring-launched
at 21:56:09 UT into an elliptical orbit with a lifetime of one month, rather
than the planned one-year orbit. Transearth injection began at 02:15:33 UT on 25
April. On 25 April at 20:43 UT Mattingly began a cislunar EVA to retrieve camera
film from the SIM bay and inspect instruments, two trips taking a total of 1
hour, 24 minutes. The CM separated from the SM on 27 April at 19:16:33 UT.
Apollo 16 splashed down in the Pacific Ocean on 27 April 1972 at 19:45:05 UT
(2:45:05 p.m. EST) after a mission elapsed timeof 265 hrs, 51 mins, 5 secs. The
splashdown point was 0 deg 43 min S, 156 deg 13 min W, 215 miles southeast of
Christmas Island and 5 km (3 mi) from the recovery ship USS Ticonderoga.
Performance of the spacecraft,
the second of the Apollo J-series missions, was good for most aspects of the
mission. The primary mission goals of inspecting, surveying, and sampling
materials in the Descartes region, emplacement and activation of surface
experiments, conducting inflight experiments and photographic tasks from lunar
orbit, engineering evaluation of spacecraft and equipment, and performance of
zero-gravity experiments were achieved despite the mission being shortened by
one day. Young, 41, was a Navy Captain who had flown on three previous
spaceflights (Gemini 3, Gemini 10, and Apollo 10; he later flew on STS-1 and
STS-9), Mattingly, 36, was a Navy lt. commander on his first spaceflight (he
later flew STS-4 and STS-51C), and Duke, 36, was an Air Force lt. colonel also
on his first spaceflight. The backup crew for this mission was Fred Haise,
Stuart Roosa, and Edger Mitchell. The Apollo 16 Command Module
"Casper" is on display at the Alabama Space and Rocket Center in
Huntsville, Alabama.
Credit:NASA
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