Kathy's Spacesuit diary

Production team

Day One

Now this seems like an intrinsically funny challenge to me. What a completely barking thing to be trying to do - keep someone cool in Death Valley on their "Mars Mission".

Barking? Yes. Easy? No. In the series on Carriacou, we completely failed to make ice, so the stakes are up for making a cooling system.

We're all quite hopeful - zeolite is amazing. The image I have is that it just sucks up moisture like mad, so using it and a partial vacuum together could help us enormously (it should help get a lower pressure by sucking the moisture out of the air).

But different zeolites will have different abilities to 'suck up' water. And even if Iain finds some, it may not be very pure - so it's great Mike is getting some from detergent too.

I spend a while thinking about the design for the 'fridge' and talking to the others. It would be easier to have one compartment with water in to cool, and zeolite suspended above it to extract evaporated water. But the zeolite gets hot, and having something hot in the same volume as the water we're trying to cool just can't be a good idea.

But the separate container I decide to make for the zeolite needs a load of holes to make the connections to the main container, and none of the drill bits are a good size for any of the decent tubing I have. It's such a small issue, but such a pain in the neck, as holes that are much too big will be hard to seal. Anything that isn't sealed will trash the vacuum we're trying to get.

A lot is frustrating here!

Day Two

Yesterday evening we all tried to pump the fridge down. Hard work. It all seemed to be working well - the pump pumped, the pressure got lower and lower, the containers all withstood the low pressures - but the blasted water temperature didn't go down very impressively. 2 degrees Celsius, maybe? That's hardly going to cool Ellen in Death Valley, and we'll all have died of heat exhaustion. Really disappointing.

We seemed to reach a pressure that we just couldn't get lower than. Jonathan's PhD required a lot of playing around with vacuums, so he has loads of experience with them, thankfully. He says we just need to be really careful about potential leaks, that seals can work really well until you hit a particular pressure, when they would start to leak, which means you just can't get to a lower pressure.

I spend the day trying to make improvements. Everyone is helping everyone else, and we're all beginning to discuss other ways of trying to reduce the temperature. For instance, chemical reactions that cause a big temperature drop. Various reactions are used to make mixtures that can freeze water (they've been used to make ice cream), so Mike B is starting to think about of trying something else ... we need all the help we can get!

Production team

Day Three

We give up all ideas of a fridge! It's a cool box. We have been able to create low pressures, which are good for insulating, like the way a thermos flask uses a vacuum to keep drinks hot or cold. Our attempts to actually reduce the temperature were pathetic, so we’ll go for an insulating cool box instead and try find other ways of getting cool water. So I wrap up water bottles in material, tie them to the top of the vehicle, water them down and we swoop off to Death Valley. We have to stop on the way to keep the material wet - it just dries out so fast in the heat and wind.

It worked, though - a load better than our attempts at fridges! Ellen, dressed like one of the sperm in Woody Allen's "Everything You Always Wanted To Know About Sex" film, heaving the trolley and 'cool box' across the jagged surface of Death Valley, was almost too funny to bear.

We all get so tense and excited at the ends of the shows. We only had one attempt, and everything had to work first time:
* the pump Jonathan and Ellen made had to pump
* the cooled water had to get used quickly and Mike's chemical reaction had to work
* the seals had to hold and the pump work for the fridge to act as a cool box

The wheels of the trolley were the thing that gave, and Ellen just kept pulling that trolley. It was hysterical, we were weeping with laughter. It was probably the best moment of the series for me (which is funny, given the failure of the fridge).