English subtitles for clip: File:0491 Moon Travel 01 30 24 00.webm

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What would it be like to
be on the moon a question

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that has intrigued men since long before
the invention of the telescope to travel

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across the roughly marked surface of our
nearest neighbor in space is an experience

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that man will soon be having probably
before this decade is over the first

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explorers from Earth will
have arrived on the moon

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but how will they explore a planet without
roads without atmosphere with gravity

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only one sixth that of Earth.

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Scientists are studying
answers to these questions.

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First by gathering information
on the conditions

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that will likely be found on the moon.

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Then by developing new concepts of travel
for vehicles such as we have never seen

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on earth to cross terrain

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that is unique to the moon
the research starts in a

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laboratory here the vacuum conditions found
on the moon are studied for the effect

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they will have on lunar soil.

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The large bell jar has been pumped down
to a very high vacuum inside as a device

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that is designed to measure the strength
of soil at its base there are two discs of

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different sizes

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and an annular ribbon the disks are
pushed straight down into the soil

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and both the vertical force applied
and the penetration are measured.

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This tells something about how much weight
the soil will be able to bear in this

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case the soil used as pumice which is believed
to be similar to certain lunar soils.

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A second test involves the annular rain.

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Or shearing as it's called a
known load is applied at the top

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and then the ring is twisted the
horizontal force being developed

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and the angle of rotation
are both measured.

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This tells us something about the amount
of traction vehicle can develop here

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the same test is shown being applied to
a gravel soil under similar conditions.

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Another effect which is studied is

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that of low gravity air being tested on a
free falling device known as an Atwood

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type machine. It reveals what happens
to a soil in gravity only one sixth

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that of Earth where one hundred
pounds weighs only sixteen arrow soil

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test disk is shown being
attached to a release

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when the test is actually run this disc
will be released into a capsule of soil

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which is falling at an acceleration
which simulates the lunar gravity.

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The entire device is raised high into the
air then dropped during the drop though

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so rapidly it could not be seen
the soil test disc is released

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and the effect of low gravity
on soil is measured.

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Based on such tests of soil properties
several vehicle models designed for Moon

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travel were developed here is a vehicle
based on the Archimedean screw principle

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propelled by the turning of four large
screws this wheeled vehicle rolls on

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six large soft tires
arranged on three axles

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and this track type vehicle is composed
of two units with wrap around tracks.

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These vehicles were tested.

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In a soil bin containing soils of a type
likely to be encountered on the lunar

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surface here the track vehicle is made
to crawl over simulated Doom's of fine

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pumice.

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The wrap around tracks are elastic with
flexible prongs to conform to the terrain

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while staring at the
pivot between the units.

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The Archimedean screw vehicle is designed
to operate only where the soil is so soft

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that it cannot support the weight of a
vehicle and it burrows through the soil.

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It is steered by running the various crew
elements at different speeds managing

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slow but effective turns.

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The electric cord trailing behind it
is used to deliver power to the model.

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It is not intended for actual moon vehicles
which will use batteries or fuel cells.

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Generally this group principle
is not very efficient.

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And would be used only for special applications
such as this exceedingly soft soil.

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The wheeled vehicle is
mechanically the most efficient

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and reliable of the three designs.

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While it cannot perform as well as a track
on soft ground its many other advantages

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make it an attractive solution to the
problem of an all around moon vehicle.

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This particular model has three axles

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or units individually driven by three
separate electric motors the axles are

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connected to each other by elastic
rods which enable the units to dip

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and roll with respect to one another.

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Steering is accomplished by the small
steering Motors mounted on the front

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and rear units. But wheel shown on
this model are made of foam rubber.

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But this would not be the case for a.

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Moon vehicle since foam rubber could never
endure the severe lunar temperatures

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instead of size design might feature
lightweight wire frames which would be covered

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with a thin top plastic material.

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In case the lunar surface does
not turn out to be a fine dust.

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But instead consists of a
rough and rocky terrain

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that wheeled vehicle will perhaps
show itself to its best advantage.

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The individually powered units have
good obstacle climbing ability even

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when the obstacles are more than twice
the height of the wheels the vehicle can

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force itself over

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and around boulders yet always hug the
terrain because of its special design which

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is called articulated.

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If obstacles such as chasms occur such as
the space between boulders the vehicle

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will bridge the obstacle
with its long body.

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Where one unit has lost traction

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and cannot pull the others will push it
along in turn if they lose traction.

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They will be pulled along so that
the vehicle remains in motion.

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Whatever the soil

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or terrain in general the wheeled vehicle
seems a promising solution to the problem

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of Moon travel yet much
work remains to be done.

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Further

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and more realistic testing in the moon
environment must still be accomplished New

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Moon vehicles will be conceived
designed and put through their paces so

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that the astronauts of tomorrow will have
the vehicles to carry them safely to the

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farthest reaches of the moon.