Sometimes the smallest things can be one
of the biggest headaches. During the
Apollo missions of 1969-72 the tiny
particles of lunar dust turned out to be
a major issue. Described as being as
finest talc but as rough as sandpaper it
also has properties that may be
dangerous for both men and machines and
has been cited as a bigger problem for
future astronauts than radiation by some
scientists the lunar surface is covered
in a thin layer of dust which has been
created by the bombardment of meteorites
and micro meteorites over millions of years.
These Smash in to the moon's surface that
speed about 12 miles or 20 kilometers
per second heating up and pulverizing
rocks and dirt which contains silica and
metal such as iron. Some of the dust is
melted in the extreme heat of the impact
which creates tiny glass beads as the
silicon melts and then cools and falls back
to the surface. This continual smashing
shatters the silica and other minerals to
produce finer and finer grains of dust
but because there is no weathering on
the moon like there is here on earth the
edges of these tiny shards which are not
only very hard
they also remain very sharp and jagged
which makes it incredibly abrasive and
potentially damaging to anything it
sticks to. NASA had an idea about the dust
before the man missions from the
previous survey Landers but it quickly
became apparent that once men were there
but that was going to be far more of a
problem than was first thought. In fact before
the mission started some scientists
thought but because the dust and not
been in contact with oxygen that it may
spontaneously combust if exposed to air.
Before the departure of Apollo 11 from
the moon, Buzz Aldrin and Neil Armstrong
had to carry out a rather ad-hoc
experiment to see if Dust was safe to bring
back into the lunar lander in an air
environment. They got a grab sample of dust
and went back to the lander they placed
some of it on the engine cover of the ascent
module, they then closed the hatch,
re-pressurized the cabin whilst looking out to see
if the dust
to smoke. Luckily it didn't and they got
on with the departure. Aldrin said
later that it had, they would stopped the
pressurization, opened the hatch and thrown out as quickly as possible.
We've seen astronauts bouncing around
on the moon surface and getting covered
in the dust but also they found the
that it sticks to anything it comes in contact
with, from the Sun visors on helmet to
gauges, dials and more importantly
things like seals on the spaces and
containers for bringing back the rock
samples. The dust is electrically charged
by the bombardment of charged particles
from the Sun and this is what makes it
stick to anything it lands on. During
Apollo 17, crew members Harrison "Jack"
Schmitt and Gene Cernan had reported
that the dust was making it difficult
for them to move their arms around
during the moonwalk because it's got
into the joints of their spacesuits. It
also scratched the gold visors on the
helmets to such an extent when they tried
to wipe it off that it made it difficult
to see, a bit like trying to clean glass
with Sandpaper. The same applied to
cameras and other optical surfaces which
had to be cleaned with a small camera
cleaning brush to avoid damage it also
damaged seals between the gloves and the
spacesuit locking ring so they started
to slowly leak air in the vacuum on the moons
surface. Just how abrasive but dust is
was revealed when it wore through almost
three layers of a Kevlar like material
on Schmitt's moon boot that he made his
way around the lunar surface. The Apollo
missions brought back 382 kilograms of
rock samples
these were placed into sealed contains to
keeping the low-pressure atmosphere the
moon in with the samples.
However, when they got back to earth it
was found that every sample box leaked
air from the cabin because the dust
has damaged the seals on the containers.
There was also no way to isolate the
crew from the dust in the landers cabin
either. There were no airlocks and
nowhere to change out of this suits other
than in the cabin.
When the crews returned to the lander
and re-pressurized cabin, on every
mission they noticed that some of the dust
became airborne and floated around the
cabin, not only coaching the inside the
craft but they also breathed it in as well.
They said that it had the smell of spent
gunpowder or wet ashes in a fire and
after the mission Gene Cernan said that it
took about three months for the embedded
dust to grow out from under his
fingernails. On Apollo 17 Schmitt said
he felt congested and complained of
"lunar dust hay fever" but the symptoms
disappeared the next day. It's because of
this but the crews were put into
quarantine when I first returned to
Earth because no one knew if there are
any biological threat on the moon or in
the dust,
although by Apollo 12 this has been
discontinued has it been confirmed from
examination on earth but it posed no
bacterial or viral risks. although the dust is
mostly silica and non-poisonous,
extremely small size of the particles it
posed a similar problem to that which
have been discovered when miners and
tunnels on earth had become ill and died
for silicosis years after dry drilling. Silicosis is where the tiny dust
particles are so small that it gets into
a very deepest parts for lung and cannot be
coughed out. The white blood cells of the
immune system cluster around the
particles and the victim eventually dies
as the lungs become more and more
effective. Another problem with the dust
and the lack of a lunar atmosphere also
came to light again with the Apollo 12
mission. When they landed it was about a
180 meters or 600 feet
from an earlier Surveyor 3 Lander which
has been there for a couple of years. The
Apollo 12 astronauts detached the camera and
mechanical scoop from a Surveyor Lander to
return to Earth. Whilst doing it they
noticed the structure of the lander had
been darkened by the cosmic radiation of
the time but some areas that
actively been sandblasted clean by the
dust blown out by the rocket engine
exhaust from Apollo 12 as it landed. This
was confirmed when the camera and
mechanical scooper examined back on earth
as they have been damaged by the
high-speed particles of dust. It's now
believed that some of the smallest
particles of dust that were rejected by
blast from the engine which can also be
seen from the landing footage could have
been blown halfway around the moon
due to the lack of atmospheric
resistance. Although most of it would
have only gone as far as high side
craters or nearby mountain ranges before
it was stopped.
It's estimated that the lunar soil or
Regolith and the dust had been traveling
at about 1,300 feet or 400 meters per
second which is as fast as a bullet from
a gun.
This means in future craft landing near
other structures buildings or even
astronauts could cause damage to them by
this sandblasting effect even at some
distance away. For future manned journeys to
the moon NASA's scientists around the
world have been working on ways control
the dust using technologies like film
coating that the dust won't stick to and
shaking the dust off with and electric
charge. As the dust particles contained
tiny pieces of nanophase iron or pure
iron and this is affected by magnetic
field,
this could be used to extract the dust
from the air infiltration systems. So if
you thought that the dust in your house
was a pain just be thankful but it's not
lunar dust.
Anyway's I hope you found this little piece
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So until the next time it's goodbye to
me :-)