Week one's challenges are heavily focused on the "exploration" theme.
Jonathan's challenge is to
make a rover; a remote controlled vehicle that could
explore strange new worlds. NASA come to Death Valley
to test out their machines, so for Jonathan's ultimate
test we subject his rover to a NASA style experiment
in the desert. But unlike NASA, Jonathan has just three
days and whatever he can find lying around the mine
to come up with a working rover.
Staying with the theme of exploration, Iain
and Ellen have to use their
geological and botanical skills to search for water
in the desert. Death Valley and the deserts around it
are some of the driest places on the planet, so they're
going to have their work cut out.
Assuming they find some water, Kathy
and Mike are going to have to
find a way of purifying it to make it safe for drinking
- an essential component for any mission into deep space.
But just to make it a bit harder, not only are they
going to have to purify it, they're going to have to
make it taste good as well, because at the end of day
three we're going to have a blind tasting. Kathy and
Mike's purified water will be up against drinking water.
Jonathan's rover is based on a wooden chassis, supported
by small bicycle wheels. It's powered by a couple of
electric drills which he cannibalises and attaches directly
to the front wheels. To steer it he changes the power
going to each wheel. But the really clever bit is the
remote control. He decides to control it by making a
musical instrument, and sending the tones to the rover
via walkie-talkie. Each different tone gives the rover
a different instruction - forward, back, turn right
or turn left.
Ellen and Iain aim to find water using the same principles
that NASA use to search for water on other planets -
they look for features in the landscape where water
has left its mark. Iain spots a gully with signs of
a recent flash flood, so they follow it in the hope
that somewhere along its course water will have been
trapped in the rocks or in the soil. Along the way Ellen
finds plants which indicate that water isn't too far
below the surface. And then they come across a tiny
desert oasis - just a few straggly trees. But even though
the soil is moist here, when they dig down they find
that the damp layer isn't very thick. So Ellen sets
up a solar still to evaporate water out of the soil.
At the same time she wraps plastic sheets around a branch
to collect the water that transpires off the leaves.
Next day they have miraculously collected 2 small jars
of rather mucky looking water. Not much for Kathy and
Mike to purify. But on the way back to base Iain uses
his geological knowledge to find one more source of
Kathy and Mike have a two pronged strategy for cleaning
the water. Mike makes activated charcoal to filter out
contaminants - it's exactly the same way that NASA clean
water on the space shuttle. But to be extra safe Kathy
makes a solar cooker to boil the water, to remove microscopic
bugs that might have crept through the filters.