Forty-one years ago, on August 1, 1971, Apollo 15 mission
commander David R. Scott relayed exciting news to Mission
Control and the scientists in the back room.
“Guess
what we just found,” Scott said. “Guess what we
just found! I think we found what we came for.”
That
sample, nicknamed the Genesis Rock, sample number 15415, was
an anorthosite, a piece of the moon’s primordial crust.
Geologists, hoping to learn more about the moon and its origins,
selected the Hadley-Apennines landing site for precisely this
reason. While not the oldest lunar sample brought back from
the moon, geologists at the Manned Spacecraft Center (now
known as the Johnson Space Center) later concluded that this
rock was about 4 billion years old.
Apollo
15 was the first of three J missions, often called the true
scientific missions to the moon. These missions featured the
Lunar Rover equipped with a television camera, a redesigned
Lunar Module (LM) that allowed the crews to stay for extended
periods on the moon and long duration backpacks for the moonwalkers
allowing astronauts to spend more time exploring the lunar
surface. Engineers also made changes to the Service Module,
filling it with remote sensing instruments designed to document
the moon’s surface. During the crew’s three spacewalks,
Scott and James B. Irwin spent almost nineteen hours exploring
the moon and covered 17.5 miles of lunar terrain in the lunar
rover.
To prepare
for this historic flight, the crew trained for months. An
important part of that training included geology field trips
with geologists from universities and the center as well as
the U.S. Geological Survey. Apollo 15, 16 and 17 crews dedicated
much more time to these exercises than their colleagues on
the earlier Apollo lunar landings. Apollo 15 astronauts traveled
to a different geological site each month, which amounted
to about 18 trips, compared to five or six for the previous
flight of Apollo 14. Scott and Irwin practiced in terrain
similar to the conditions they would find on the moon and
within the limitations they would face on the surface.
Gary
E. Lofgren helped train the Apollo 15 crew and now serves
as the lunar curator. “You’d draw a circle around
how far they could go,” Lofgren explained. “So
this is the area that they can move around in. They couldn’t
get farther from the LM than a certain distance … The
amount of area that they could traverse was pretty small.
We would pick out spots, and then we would tell them to collect
the kinds of samples that were obvious to collect at that
site: collect a sample of the soil and a sample of the rocks.”
During
these traverses the crew gained skills in identifying rocks,
describing terrain, documenting samples as well as proper
sampling techniques. Sometimes they test drove Grover, a one-G
rover.
CapCom
Joseph P. Allen and scientists also gained valuable experience
as they sat in a separate simulated control room and science
support room. Scott and Irwin communicated by radio to Allen,
as they would during their flight. Following the simulation,
instructors who walked along with the two men pointed out
what they had overlooked in their traverse.
In preparation
for their landing in the Hadley-Apennine region, the instructors
along with Scott and Irwin, visited volcanic sites like Hawaii
and areas “where they would see the kinds of rocks we
expected to find as part of that primitive crust,” Lofgren
noted. These sites included the San Gabriel Mountains, Ely,
Minnesota, the Rio Grande Gorge and the San Juan Mountains.
Their training paid off in spades. Leon T. Silver, an Apollo
15 instructor from Cal Tech, called the mission the “apotheosis
of all the things we’d been planning to do… it
was the coming together of developing the technical capabilities,
preparing men to be explorers as well as many, many other
things.”
He and
others were confident that they would find a piece of the
ancient crust. Why did these scientists place such faith in
two former test pilots? “Well,” he explained,
“that’s because the human intention, well educated,
well prepared, can squeeze things out, you understand?”
For more
information on the crew training, traverses, and experiences
of some of the instructors for Apollo 15, read some selected
oral history interview excerpts available on the JSC History
Portal: http://www.jsc.nasa.gov/history/special_events/Apollo15.htm
View
the Apollo 15 photo gallery!
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