everyone thinks of space as very cold, in fact, if you
stood on the sunny side of the moon, the temperature would
be hot enough to boil the blood in your body. Spacesuits
are designed to protect astronauts from these extremes
of temperature. So for this week's challenge the Rough
Scientists have to collectively design a cooling system
for their very own spacesuit. And to test it out, at the
end of day three, they're going to have to go to Death
Valley and do a mock moon walk in their spacesuit - hopefully
staying deliciously cool.
They decide that they need to make a portable Rough
Science fridge. Ellen creates
a copper pipe system that will go from the fridge to
the spacesuit, carrying cool water from the fridge to
the astronaut. Jonathan devises a pump to keep the water
moving through the system.
Kathy suggests that the fridge
should use the principle of evaporation - the same principle
that cools us when we sweat. She needs to get water
evaporating inside the fridge. And the best way to do
that is to lower the pressure; this speeds up evaporation
and therefore cooling. But there's a problem - all that
evaporating water is trapped inside the fridge, and
unless they can get it out then it will destroy the
vacuum. Fortunately there's a magic mineral called zeolite
that has a special property - it absorbs water vapour.
So if they can find zeolite and put it in the fridge
it will suck up the water vapour, preserving the vacuum.
Mike attempts to extract zeolite
from washing powder, whilst Iain
tries to find naturally occurring zeolite in the rocks
around the mine.
So at the end of day three the Rough Scientists decamp
to Death Valley where Ellen is dressed in their spacesuit
for a spacewalk which will reveal whether their cooling
system really can keep someone cool in one of the hottest
places on Earth.