Multimedia Mania/abacus-multimedia-mania.iso/dp/0097/00976.txt

Text File | 1993-07-27 | 23KB | 400 lines

$Unique_ID{bob00976}
$Pretitle{}
$Title{Apollo Expeditions To The Moon
Chapter 12: Ocean Of Storms And Fra Mauro}
$Subtitle{}
$Author{Conrad, C., Jr.;Shepard, A.B., Jr.}
$Affiliation{NASA}
$Subject{surface
lunar
apollo
crater
moon
samples
feet
first
site
dust}
$Date{1975}
$Log{}
Title:       Apollo Expeditions To The Moon
Author:      Conrad, C., Jr.;Shepard, A.B., Jr.
Affiliation: NASA
Date:        1975

Chapter 12: Ocean Of Storms And Fra Mauro

     Scientific exploration of the Moon began in earnest with the Apollo 12
and 14 missions.  Four astronauts worked on the Moon in four-hour shifts,
walking from site to site.  The Apollo 12 astronauts carried everything:
experiments, equipment, tools, sample bags, cameras.  The Apollo 14 team had a
small equipment cart, and some of the time it was a help.  But the missions
showed that a man in a pressurized suit had definite limitations on the rugged
and perplexing lunar surface.  It was more work than it seemed, and in the
case of Apollo 14, medical advice from Earth ended one phase of activity. But
the two missions produced a wealth of new scientific data and lunar samples,
and both laid a firm foundation for the great voyages of lunar exploration to
follow.

     The sky was cloudy and rain was falling on November 14,1969, as the
Apollo 12 crew prepared for launch.  Half a minute after liftoff a lightning
strike opened the main circuit breakers in the spacecraft.  Quick action by
the crew and Launch Control restored power, and Astronauts Charles "Pete"
Conrad, Jr., Richard F. Gordon, and Alan L. Bean sped into sunlight above the
clouds.  "We had everything in the world drop out," Conrad reported.  "We've
had a couple of cardiac arrests down here too," Launch Control radioed back.

     Their destination was the Ocean of Storms.  Four and a half days later,
Conrad and Bean entered the lunar module Intrepid and separated from Gordon in
the command module Yankee Clipper.  Their landing site was about 1300 miles
west of where Apollo 11 had landed, on a surface believed covered by debris
splashed out from the crater Copernicus some 250 miles away.  The exact site
was a point where, 31 months before, the unmanned lunar scout Surveyor III had
made a precarious automatic landing.  The Surveyor site was a natural choice:
it was a geologically different surface, it would demonstrate pinpoint landing
precision, and it would offer a chance to bring back metal, electronic, and
optical materials that had soaked for many months in the lunar environment.

     Here is Pete Conrad's account of the mission:

     It was really pioneering in lunar exploration.  We had planned our
traverses carefully, we covered them, and we stayed on the time line.  We had
a real-time link with the ground, to help guide our work on the surface.  Of
course we had practiced a lot beforehand, working with geologists in the field
to learn techniques from them while they learned what we could and couldn't do
in the lunar environment.

     Our first important task was the precision landing near Surveyor III.
When we pitched over just before the landing phase, there it was, looking as
if we would land practically on target.  The targeting data were just about
perfect, but I maneuvered around the crater, landing at a slightly different
spot than the one we had planned.  In my judgment, the place we had pre-
picked was a little too rough.  We touched down about 600 feet from the
Surveyor.  They didn't want us to be nearer than 500 feet because of the risk
that the descent engine might blow dust over the spacecraft.

     Our second important task - and of course the real reason for going to
the Moon in the first place - was to accomplish useful scientific work on the
surface.  We had to set up the ALSEP and its experiments; we had to do a lot
of geologizing; and finally we had to bring back some pieces of the Surveyor,
so they could be analyzed for the effects of their exposure.

     Al Bean and I made two EVAs, each lasting just under four hours; and we
covered the planned traverses as scheduled.  We learned things that we could
never have found out in a simulation.  A simple thing like shoveling soil into
a sample bag, for instance, was an entirely new experience.  First, you had to
handle the shovel differently, stopping it before you would have on Earth, and
tilting it to dump the load much more steeply, after which the whole sample
would slide off suddenly.

Little Clouds Around Your Feet

     And the dust!  Dust got into everything.  You walked in a pair of little
dust clouds kicked up around your feet.  We were concerned about getting dust
into the working parts of the spacesuits and into the lunar module, so we
elected to remain in the suits between our two EVAs.  We thought that it would
be less risky that way than taking them off and putting them back on again.

     On the first EVA, the first thing I did was to take the contingency
sample.  When Al joined me on the surface, we started with the experimental
setups.  We set out the solar wind experiment and the ALSEP items.  We planted
the passive seismic experiment, deployed and aligned antennas, laid out the
lunar surface magnetometer, and took core samples.  Some of the experiments
started working right away as planned, sending data back.  Others weren't set
to start operating until after we had left.

     We were continually describing what we were doing; we kept up a stream of
chatter so that people on the ground could follow what was going on if we were
to lose the video signal.  And we did lose it, too, soon after we landed. That
was hard to take.

     One strange surface phenomenon was a group of conical mounds, looking for
all the world like small volcanoes.  They were maybe five feet tall and about
fifteen feet in diameter at the base.  Both of us really enjoyed working on
the surface; we took a lot of kidding later about the way we reacted.  But it
was exciting; there we were, the third and fourth people on the Moon, doing
what we were supposed to do, what we had planned to do, and keeping within
schedule.  Add to that the excitement of just being there, and I think we
could be forgiven for reacting with enthusiasm.

     Our second EVA was heavily scheduled.  We were to make visual
observations, collect a lot more samples, document photographically the area
around the Ocean of Storms, and - if we could bring back pieces of the
Surveyor III spacecraft.  We had rehearsed that part with a very detailed
mockup before the flight, and were well prepared.

     We moved on a traverse, picking up samples and describing them and the
terrain around them, as well as documenting the specific sites with
photography.  We rolled a rock into a crater so that scientists back on Earth
could see if the seismic experiment was working. (It was sensitive enough to
pick up my steps as I walked nearby.) Anyway, we rolled the rock and they got
a jiggle or two, indicating that experiment was off and running.

Tan Dust on Surveyor

     We found some green rocks, and some gray soil that maintained its light
color even below the surface, which is not common, and we finally reached the
Surveyor crater.  I was surprised by its size and its hard surface.  We could
have landed right there, I believe now, but it would have been a scary thing
at the time.  The Surveyor was covered with a coating of fine dust, and it
looked tan or even brown in the lunar light, instead of the glistening white
that it was when it left Earth more than two years earlier.  It was decided
later that the dust was kicked up by our descent onto the surface, even though
we were 600 feet away.

     We cut samples of the aluminum tubing, which seemed more brittle than the
same material on Earth, and some electrical cables.  Their insulation seemed
to have gotten dry, hard, and brittle.  We managed to break off a piece of
glass, and we unbolted the Surveyor TV camera.  Then Al suggested that we cut
off and take back the sampling scoop, and so we added that to the collection.

     Then we headed back to the Intrepid.  We retrieved the solar-wind
experiment, stowed it and the sample bags in the Intrepid, got in, buttoned it
up, and started repressurization.  Altogether we brought back about 75 pounds
of rocks, and 15 pounds of Surveyor hardware.  We also brought back the
25-pound color TV camera from Intrepid so that its failure could be
investigated.

     While we were busy on the surface, Dick Gordon was busy in lunar orbit.
The Yankee Clipper was a very sophisticated observation and surveying
spacecraft.  One of the experiments that Dick performed was multispectral
photography of the lunar surface, which gave scientists new data with which to
interpret the composition of the Moon.

     After Al and I got back to Yankee Clipper following lunar liftoff and
rendezvous, all three of us worked on the photography schedule.  We were
looking specifically for good coverage of proposed future landing sites,
especially Fra Mauro, which was then scheduled for Apollo 13.  That's a rough
surface, and we wanted to get the highest resolution photos we could so that
the crew of the Apollo 13 mission would have the best training information
they could get.

     We changed the plane of our lunar orbit to cover the sites better, and we
also elected to stay an extra day in lunar orbit so that we could complete the
work without feeling pressured.  We took hundreds of stills, and thousands of
feet of motion-picture film of the Fra Mauro site, and of the Descartes and
Lalande craters, two other proposed landing sites.

     Meantime the experiments we had left on the lunar surface were busy
recording and transmitting data.  They all worked well, with one exception,
and were really producing useful data.  One unexpected result came from the
seismic experiment recording the impact of Intrepid on the surface after we
had jettisoned it.  The entire Moon rang like a gong, vibrating and resonating
for almost on hour after the impact.  The best guess was that the Moon was
composed of rubble a lot deeper below its surface than anybody had assumed.
The internal structure, being fractured instead of a solid mass, could bounce
the seismic energy from piece to piece for quite a while.

     The same phenomenon was observed at two ALSEP stations when the Apollo 14
crew jettisoned their lunar module Antares and programmed it to crash between
the Apollo 12 and 14 sites.

     With every mission after Apollo 12, additional seismic calibrations were
obtained by aiming the Saturn S-IVB stage to impact a selected point on the
Moon after separation from the spacecraft.  The seismic vibrations from these
impacts lasted about three hours.

     Apollo 13 was supposed to land in the Fra Mauro area.  The explosion on
board wiped out that mission, and it became instead a superb example of a
crew's ability to turn a very risky situation into a safe return to Earth.

     So the Fra Mauro site was reassigned to Apollo 14, because scientists
gave that area a high priority.  The following account is by Alan B. Shepard,
Jr., the first American into space and one of the original seven astronauts.

     The Fra Mauro hills stand a couple of hundred of miles to the east of the
Apollo 12 landing site.  I was selected to command this mission, my first
since the original Mercury flight in 1961.  With me to the lunar surface went
Edgar D. Mitchell in Antares, while Stuart A. Rosa was the command module
pilot of Kitty Hawk.

Choosing a Smoother Spot

     The targeting data for the Apollo 14 landing site were every bit as good
as the data for Apollo 12; but we had to fly around for a little while for the
same reason they had to.  The landing site was rougher, on direct observation,
than the photos had been able to show.  So I looked for a smoother area, found
one, and landed there.

     Our first EVA was similar to those before; we got out, set up the solar-
wind experiment and the flag, and deployed the ALSEP.  The latter had two new
experiments.  One was called the "thumper." Ed Mitchell set up an array of
geophones, and then walked out along a planned survey line with a device that
could be placed against the surface and fired, to create a local impact of
known size.  Thirteen of the 21 charges went off, registering good results.
The other different experiment we had was a grenade launcher, with four
grenades to be fired off by radio command some time after we had left the
Moon.  They were designed to impact at different distances from the launcher,
to get a pattern of seismic response to the impact explosions.

     While Ed and I were working on our first EVA, Stu was doing the
photographic part of the orbital science experiments.  One job was to get
detailed photographic coverage of the proposed site for the Apollo 15 mission,
near the Descartes crater.

     He was asked also to get a number of other photos of the lunar surface,
in areas that had not been well-covered in earlier missions.  Stu produced
some great photos of the surface, rotating the command module Kitty Hawk to
compensate for the motion of the image.  He photographed the area around
Lansberg B, which had been the predicted impact site of the Apollo 13 S-IVB
stage.  It was calculated that the impact could have produced a crater about
200 feet in diameter, and scientists wanted good pictures of the area so they
could search for the brand-new crater on the Moon.

     Stu also found them another new crater on the back side of the Moon.  It
was serendipity; he was shooting other pictures and suddenly this very bright,
young crater came into view directly under Kitty Hawk.  So he swung the camera
around, pushed the button, and then went back to his original assignment.

A Lunar Rickshaw

     Ed and I worked on the surface for 4 hours and 50 minutes during our
first EVA; after the return to Antares, a long rest period, and then
resulting, we began the second EVA.  This time we had the MET-modularized
equipment transporter, although we called it the lunar rickshaw - to carry
tools, cameras, and samples so we could work more effectively and bring back a
larger quantity of samples.

     Our planned traverse was to take us from Antares more or less due east to
the rim of Cone crater.  That traverse had been chosen because scientists
wanted samples and rocks from the crater's rim.  The theory is that the oldest
rocks from deep under the Moon's surface were thrown up and out of the crater
by the impact, and that the ones from the extreme depth of the crater were to
be found on the rim.

     On our way to the crater, one of the first things Ed did was to take a
magnetometer reading at the first designated site.  When he read the numbers
over the air, there was some excitement back at Houston because the readings
were about triple the values gotten on Apollo 12.  They were also higher than
the values Stu was reading in the Kitty Hawk, and so it seemed that the Moon's
magnetic field varied spatially.

     Our first sampling began a little further on, in a rock field with
boulders about two or three feet along the major dimension.  These were
located in the centers of a group of three craters, each about sixty feet
across.  Like the bulk of the samples brought back, these were documented
samples.  That means photographing the soil or rocks, describing them and
their position over the voice link to Mission Control, and then putting the
sample in a numbered bag, identifying the bag at the same time on the voice
hookup.

     Apollo 14 tried an experiment to do something constructive about the dust
that plagued all of the missions.  NASA engineers wanted to check out some of
the finishes proposed for the Rover and other pieces of operating equipment.
I had a group of samples - material chips with different finishes - and I
dusted them with the surface dust, shook them off, and then brushed one set to
try to determine the abrasive effects, if any, of such dust removal. The other
set was left unbrushed as a control sample.  All this was of course recorded
with the closeup camera.

     The mapped traverse was to take us nearly directly to the rim of Cone
crater, a feature about 1000 feet in diameter.  As we approached, the boulders
got larger, up to four and five feet in size.  And at this time, the going
started to get rough for us.  The terrain became more steep as we approached
the rim, and the increased grade accentuated the difficulty of walking in soft
dust.

The Hunt for the Rim of Cone

     Another problem was that the ruggedness and unevenness of the terrain
made it very hard to navigate by landmarks, which is the way a man on foot
gets around.  Ed and I had difficulty in agreeing on the way to Cone, just how
far we had traveled, and where we were.  We did some more sampling, and then
moved on toward Cone, into terrain that had almost continuous undulations, and
very small flat areas.  Soon after that, the surface began to slope upward
even more steeply, and it gave us the feeling that we were starting the last
climb to the rim of Cone.  We passed a rock which had a lot of glass in it,
and reported to Houston that it was too big to pick up.

     We continued, changing our suit cooling rates to match our increased work
output as we climbed, and stopping a couple of times briefly to rest. For a
while, we picked up the cart and carried it, preferring to move this way
because it was a little faster.

     And then came what had to be one of the most frustrating experiences on
the traverse.  We thought we were nearing the rim of Cone, only to find we
were at another and much smaller crater still some distance from Cone.  At
that point, I radioed Houston that our positions were doubtful, and that there
was probably quite a way to go yet to reach Cone.

     About then, there was a general concurrence that maybe that was about as
far as we should go, even though Ed protested that we really ought to press on
and look into Cone crater.  But in the end, we stopped our traverse short of
the lip and turned for the walk back to Antares.

     Later estimates indicated we were perhaps only 30 feet or so below the
rim of the crater, and yet we were just not able to define it in that
undulating and rough country.

     One of the rocks we sampled in that area was a white breccia (a rock made
up of pieces of stone embedded in a matrix).  The white coloring came from the
very high percentage of feldspar that was in the breccia.  That rock, and
others in the area, were believed to approach 4.6 billion years in age.

     We stopped at Weird crater, for more sampling and some panoramic
photography, and then continued the return traverse.  At the Triplet craters,
more than three quarters of the way back to Antares, we stopped again.  Ed's
job there was to drive some core tubes; I was to dig a trench to check the
stratification of the surface.  But the core material was granular and slipped
out of the tube every time Ed lifted it clear of the surface.  I wasn't having
any better luck with my trenching, because the side walls kept collapsing. I
did get enough of a trench dug so that I could observe some stratification of
the surface materials, seeing their color shift into the darker browns and
near blacks, and then into a surprisingly light-colored layer underneath the
darkest one.

     That was it.  Antares was in sight, as it had been throughout much of the
traverse, and our long Moon walk was almost over.  I went on past Antares to
the ALSEP site to check antenna alignment because of reports from Houston that
a weak signal was being received.  Ed took some more samples from a nearby
field of boulders.

     At that, our surface tasks were done, with the exception of recovering
the solar wind experiment and getting back into Antares for the return flight.
We had covered a distance of about two miles and collected samples during four
and one-half hours on the surface in the second EVA.  I also threw a makeshift
javelin, and hit a couple of golf shots.

     After liftoff there were still experiments to do.  The first of these was
another seismic event, generated by the impact of the jettisoned "Antares" on
the Moon.  Again the Moon responded with that resonant ringing for some time
after the event.  Once we were on our way back to Earth, we did a series of
four experiments in weightlessness.  One was a simple metal casting
experiment, to see what the effects of zero gravity would be on the purity or
the homogeneity of the mass.  The materials included some pure samples, and
others with crystals or fibers for strengthening.  As you might expect, the
materials turned out to be more homogeneous under zero-gravity conditions.  We
measured heat flow and convection in some samples and, sure enough, zero
gravity changed those characteristics also.  We did some electrophoretic
separations, which are techniques used by the pharmaceutical industry to make
vaccines, in the belief that maybe zero-gravity conditions could simplify a
complex and expensive process.  Finally, we did some fluid transfer
experiments, simply trying to pour a fluid from one container to another in
zero gravity.  The surface tension works against you there, and so it was much
easier when the containers being used were equipped with baffles that the
fluid could cling to, as it were.

     That was our mission.  Our return was routine, our landing on target, and
our homecoming as joyous as those before.

     I look back now on the flights carrying Pete's crew and my crew as the
real pioneering explorations of the Moon.  Neil, Buzz, and Mike in Apollo 11
proved that man could get to the Moon and do useful scientific work, once he
was there.  Our two flights - Apollo 12 and 14 - proved that scientists could
select a target area and define a series of objectives, and that man could get
there with precision and carry out the objectives with relative ease and a
very high degree of success.  And both of our flights, as did earlier and
later missions, pointed up the advantage of manned space exploration.  We all
were able to make minor corrections or major changes at times when they were
needed, sometimes for better efficiency, and sometimes to save the mission.

     Apollo 12 and 14 were the transition missions.  After us came the lunar
rover, wheels to extend greatly the distance of the traverse and the quantity
of samples that could be carried back to the lunar module.  And on the last
flight, a trained scientist who was also an astronaut went along on the
mission.

     I'd like to look on that last flight as just a temporary hold in the
exploration of space.