Apollo 12 was the sixth manned flight in the
Apollo program and the second to land
on the
Moon. The mission was commanded by
Charles "Pete" Conrad. It was launched
on November 14, 1969, four months after
Apollo
11. Conrad and Lunar Module Pilot
Alan
L. Bean performed just over one day
and seven hours of lunar surface activity while
Command Module Pilot
Richard F Gordon remained in lunar
orbit.
The
landing site for the mission was the Ocean of Storms
. Key objectives were achievement of a more
precise landing (which had not been achieved by Apollo 11), and to
visit the
Surveyor 3 probe to remove
parts for analysis. The mission ended on November 24 with a
successful
splashdown having completed
the main mission parameters successfully.
Crew
Backup crew
Support crew
Flight directors
- Gerry Griffin, Gold team
- Pete Frank, Orange team
- Cliff Charlesworth, Green team
- Milton Windler, Maroon team
Mission parameters
LM — CSM docking
- Undocked: November 19, 1969 – 04:16:02
UTC
- Redocked: November 20, 1969 – 17:58:20
UTC
EVAs
EVA 1 start: November 19, 1969, 11:32:35 UTC
- Conrad — EVA 1
- Stepped onto Moon: 11:44:22 UTC
- LM ingress: 15:27:17 UTC
- Bean — EVA 1
- Stepped onto Moon: 12:13:50 UTC
- LM ingress: 15:14:18 UTC
EVA 1 end: November 19, 15:28:38 UTC
- Duration: 3 hours, 56 minutes, 03 seconds
EVA 2 start: November 20, 1969, 03:54:45 UTC
- Conrad — EVA 2
- Stepped onto Moon: 03:59:00 UTC
- LM ingress: 07:42:00 UTC
- Bean — EVA 2
- Stepped onto Moon: 04:06:00 UTC
- LM ingress: 07:30:00 UTC
EVA 2 end: November 20, 07:44:00 UTC
- Duration: 3 hours, 49 minutes, 15 seconds
Mission highlights
 Alan Bean descends from the LM.
|
 Alan Bean pictured by Pete Conrad
(reflected in Bean's helmet) (NASA)
|
 Bean, Surveyor 3 and the LM
Intrepid (NASA)
|
 Conrad jiggles the Surveyor III
craft.
|
Photograph of the plaque attached to the Apollo 12 LM
|
Launch and transfer
Apollo 12 launched on schedule, during a rainstorm. 36.5 seconds
after lift-off from Kennedy Space Center, the vehicle triggered a
lightning discharge through itself and
down to the earth through the Saturn's ionized plume. Protective
circuits on the fuel cells in the service module falsely detected
overloads and took all three
fuel cells
offline, along with much of the CSM instrumentation. A second
strike at 52 seconds after launch knocked out the "8-ball"
attitude indicator. The telemetry stream
at Mission Control was garbled nonsense. However, the Saturn V
continued to fly correctly; the strikes had not affected the Saturn
V's Instrument Unit.
The loss of all three fuel cells put the CSM entirely on batteries.
They were unable to maintain normal 28V DC bus voltages into the
heavy 75 amp launch loads. One of the
AC
inverters dropped offline. These power supply problems lit
nearly every warning light on the control panel and caused much of
the instrumentation to malfunction.
EECOM John Aaron
remembered the telemetry failure pattern from an earlier test when
a power supply malfunctioned in the CSM Signal Conditioning
Equipment (SCE). The SCE converts raw signals from instrumentation
to standard voltages for the spacecraft instrument displays and
telemetry encoders.
Aaron made a call: "Try SCE to aux". This switched the SCE to a
backup power supply. The switch was fairly obscure and neither the
Flight Director,
CAPCOM, nor Commander Conrad
immediately recognized it. Lunar module pilot Alan Bean, flying in
the right seat as the CSM systems engineer, remembered the SCE
switch from a training incident a year earlier when the same
failure had been
simulated. Aaron's quick
thinking and Bean's memory saved what could have been an
aborted mission. Bean put the fuel cells
back on line, and with telemetry restored, the launch continued
successfully. Once in earth
parking
orbit, the crew carefully checked out their spacecraft before
re-igniting the
S-IVB third stage for
trans-lunar injection. The lightning
strikes had caused no serious permanent damage.
Initially it was feared that the lightning strike could have caused
the command module's parachute mechanism to prematurely fire,
disabling the explosive bolts that open the parachute compartment
to deploy them.
If they were indeed disabled, the command
module would have crashed uncontrollably into the Pacific Ocean
at the end of the mission and killed the crew
instantly. Since there was no way to figure out whether or
not this was the case, ground controllers decided not to tell the
astronauts about the possibility. Fortunately, the parachutes did
deploy and function nominally at the end of the mission.
After lunar module separation, the S-IVB was intended to fly into
solar orbit. The S-IVB auxiliary propulsion system was fired and
the remaining propellants vented to slow it down to fly past the
moon's trailing edge (the Apollo spacecraft always approached the
moon's leading edge). The moon's gravity would then slingshot the
stage into solar orbit. However, a small error in the state vector
in the Saturn's guidance system caused the S-IVB to fly past the
moon at too high an altitude to achieve earth escape velocity. It
remained in a semi-stable earth orbit after passing the Moon on
November 18, 1969. It finally escaped earth orbit in 1971 but was
briefly recaptured in Earth orbit 31 years later. It was discovered
by amateur astronomer
Bill Yeung who gave
it the temporary designation
J002E3 before it
was determined to be an artificial object.
Landing
The Apollo 12 mission landed on an area of the Ocean of Storms that
had been visited earlier by several unmanned missions (
Luna 5,
Surveyor 3, and
Ranger 7).
The International Astronomical
Union, recognizing this, christened this region Mare Cognitum
(Known Sea). The landing site would
thereafter be listed as
Statio
Cognitum on lunar maps (Conrad and Bean did not formally
name their landing site, interestingly enough, though the intended
touchdown point was nicknamed
Pete's Parking Lot by
Conrad).
The second lunar landing was an exercise in precision targeting,
using a
Doppler Effect radar
technique developed to allow the pinpoint landings needed for
future Apollo missions. Most of the descent was automatic, with
manual control assumed by Conrad during the final few hundred feet
of descent. Unlike
Apollo 11
where Neil Armstrong took partial control of the lander and
directed it further down range when he noticed that the intended
landing site was strewn with boulders, Apollo 12 succeeded, on
November 19, in landing within walking distance (less than 200
meters) of its intended target - the
Surveyor 3 probe, which had landed on the
Moon in April 1967.
Conrad actually landed
Intrepid short of
Pete's
Parking Lot because the planned landing point looked rougher
than anticipated during the final approach to touchdown. The
planned landing point was a little under from
Surveyor 3,
a distance that was chosen to eliminate the possibility of lunar
dust (being kicked up by
Intrepid's descent engine during
landing) from covering
Surveyor 3. But the actual
touchdown point — from
Surveyor 3 — did cause a thin film
of dust to coat the probe, giving it a light tan hue.
EVAs
When Conrad, who was somewhat shorter than
Neil Armstrong, stepped onto the lunar
surface, his first words were "Whoopie! Man, that may have been a
small one for Neil, but that's a long one for me." This was not an
off-the-cuff remark: Conrad had made a $500 bet with reporter
Oriana Fallaci he would say these
words, after she had queried whether NASA had instructed Neil
Armstrong what to say as he stepped onto the Moon. Conrad later
said he was never able to collect the money.
To improve the quality of television pictures from the Moon, a
color camera was carried on Apollo 12 (unlike the monochrome camera
that was used on
Apollo 11).
Unfortunately, when Bean carried the camera to the place near the
lunar module where it was to be set up, he inadvertently pointed it
directly into the Sun, destroying the
vidicon tube. Television coverage of this
mission was thus terminated almost immediately.
Apollo 12 successfully landed within walking distance of the
Surveyor 3 probe. Conrad and
Bean removed pieces of the probe to be taken back to Earth for
analysis. It is claimed that the common
bacterium Streptococcus mitis was found to
have accidentally contaminated the spacecraft's camera prior to
launch and survived dormant in this harsh environment for two and a
half years. However, this finding has since been disputed: see
Reports of
Streptococcus mitis on the moon.
Astronauts Conrad and Bean also collected rocks and set up
equipment that took measurements of the Moon's seismicity, solar
wind flux and magnetic field, and relayed the measurements to
Earth. The instruments were part of the first complete
nuclear-powered
ALSEP station set up by
astronauts on the moon to relay long-term data from the lunar
surface. The previous
Apollo 11
instruments were not as extensive or designed to operate long term.
The astronauts also took photographs, although by accident Bean
left several rolls of exposed film on the lunar surface. Meanwhile
Gordon, on board the
Yankee Clipper in lunar orbit, took
multispectral photographs of the surface.
The lunar plaque attached to the descent stage of
Intrepid
is unique in that unlike the other
lunar
plaques, it (a) did not have a depiction of the Earth, and (b)
it was textured differently (the other plaques had black lettering
on polished stainless steel while the Apollo 12 plaque had the
lettering in polished stainless steel while the background was
brushed flat).
Return
Apollo 12 recovery by the
USS
Hornet.
Intrepid's ascent stage was dropped (per normal
procedures) after Conrad and Bean rejoined Gordon in orbit. It
impacted the Moon on November 20, 1969 at . The seismometers the
astronauts had left on the lunar surface registered the vibrations
for more than an hour.
The crew stayed an extra day in lunar orbit taking photographs, for
a total lunar surface stay of thirty-one and a half hours and a
total time in lunar orbit of eighty-nine hours.
On the return flight to Earth after leaving lunar orbit, the crew
of Apollo 12 witnessed (and photographed) a solar
eclipse, though this one was of the Earth eclipsing
the sun.
Yankee
Clipper returned to Earth on November 24, 1969, at 20:58
UTC (3:58pm EST, 10:58am HST), approximately 500 miles
(800 km) east of American Samoa
. During landing, a 16 mm camera
dislodged from storage and struck Bean in the forehead, rendering
him briefly unconscious. He suffered a mild concussion, and needed
six stitches.
The
Yankee Clipper is displayed at the Virginia Air and Space Center,
Hampton,
Virginia
.
Its
recovery ship, the USS Hornet
, is now open to the public as a museum in Alameda,
California
.
The
Surveyor 3 camera retrieved by the Apollo 12 astronauts now resides
in the Exploring the Planets gallery at the National Air and
Space Museum
.
Attempted stunts
- Alan Bean smuggled a camera-shutter self-timer device on to the mission with the
intent of taking a photograph with himself, Pete Conrad and the
Surveyor 3 probe in the frame. As the timer was not part of their
standard equipment, such an image would have thrown post-mission
photo analysts into confusion over how the photo was taken.
However, the self-timer was misplaced during the EVA and the plan
was never executed.
- The Apollo 12 backup crew managed to insert into the
astronaut's lunar checklist (attached to the wrists of Conrad's and
Bean's spacesuits) reduced sized pictures of Playboy centerfolds, surprising Conrad and Bean when
they looked through the checklist flip-book during their first EVA.
The Lunar Surface Journal website [110] contains a PDF with the photocopies of their
cuff checklists showing these photos. The checklists also contain
two pages of pre-prepared complex geological terminology at the
back, to be used for the confusion of the ground crew.
- The artist Forrest Myers
claims to have installed the art piece "Moon Museum" on "a leg of
the Intrepid landing module with the help of an unnamed engineer at
the Grumman Corporation after attempts to move the project forward
through NASA's official channels were unsuccessful."
- Alan Bean left two mementos on the moon at Statio
Cognitum: his silver astronaut
pin, and Clifton Williams's
pilot wings. Williams was originally
scheduled as Apollo 12's command module pilot, but died in a
training accident. Bean left his silver astronaut pin, signifying
an astronaut who completed training but had not yet flown in space,
for personal reasons. He was to get a gold astronaut pin for
successfully completing the mission after the flight and felt he
wouldn't need the silver pin thereafter.
Mission insignia
The Apollo 12 mission patch shows the crew's Navy background. It
features a
clipper ship arriving at the
moon. The ship trails fire and flies the flag of the United States.
The mission name APOLLO
XII and the crew names
are on a wide gold border, with a small blue trim. Blue and gold
are traditionally Navy colors. The patch has four stars on it — one
each for the three astronauts who flew the mission and one for
Clifton Williams. Williams was
killed on October 5, 1967, after a mechanical failure caused the
controls of his T-38 trainer to stop responding. He trained with
Conrad and Gordon as part of the back-up crew for what would be the
Apollo 9 mission, and would have been
assigned as Lunar Module pilot for Apollo 12.
Spacecraft location
The Apollo
12 Command Module Yankee Clipper is on display at Virginia
Air and Space Center, Hampton, Virginia.
The Lunar Module
Intrepid impacted the Moon November 20,
1969 at 22:17:17.7 UT (5:17 PM EST) .
In 2002, astronomers thought they might have discovered another
moon orbiting Earth, which they designated J002E3. But it turned
out to be the third stage of the Apollo 12 Saturn V rocket..
In 2009, the
Lunar
Reconnaissance Orbiter photographed the Apollo 12 landing site.
The
Intrepid lunar module descent stage, experiment
package (ALSEP), Surveyor 3 spacecraft and astronaut footpaths are
all visible.
Depiction in media
Portions of the Apollo 12 mission are dramatized in the miniseries
From the
Earth to the Moon episode entitled "
That's All
There Is". Conrad, Gordon and Bean were portrayed by
Paul McCrane,
Tom
Verica and
Dave Foley, respectively.
Conrad had been portrayed by a different actor,
Peter Scolari, in the first two
episodes.
See also
References
Notes
- Lunar sites
- source NASA History
- "Apollo 11: 1969 Year in Review, UPI.com"
- Video footage of landing on YouTube
- WaPo July 1999
- Andrew Chaikin, A Man on the Moon. Penguin Books,
1994, p. 261.
- hq.nasa.gov , One Small Step . See also:
Apollo TV
camera
- NASA Headlines
- National Air
and Space Museum
- Boing Boing
- NASA
- Moon Museum
Bibliography
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