Kathy's Rover Diary

Production team

Day One

We're all after water ... Ellen and Ian finding it, me and Mike B purifying it, Jonathan perhaps finding it with a Mars Rover.

Mike B and I decide to separate the tasks - I need to boil the water for at least ten minutes to kill all the bugs, and he will filter it. Of course, I could simply throw it on a fire in a tin but I'd probably lose too much by evaporation, get junk in it from the fire, and I wouldn’t be able to see when it began to boil anyway. The sun's so intense here - I must be able to use its energy to boil water.

Ellen and Jonathan boiled water in Series 2 in Cariacou, so I could just use a parabolic mirror. But they take a lot of time to make and they just focus the light onto one point. I decided to try a funnel-shaped mirror, so that the light is focused all along the length of a whole jar with water in it, so the heating effect is spread out more.

Given we have the tin foil, it's relatively straightforward to focus light. I managed to build a funnel, find some jars with decent seals and spray them black so they'll absorb energy well. I had a go at getting them hot in the sun too. Not quite sure they'll boil water though. Played around with a few different shapes of funnel, too.

Day Two

I try out an alternative material for the funnel. The tin foil is easy to use, but it creases up too easily, scattering light in lots of different directions. So I cut a funnel out of thicker metal. It's a bit of a nightmare to handle, but will do the job better I think.

I also try out a black pot, between glass sheets, inside an inner tube. It actually worked quite well, but nowhere near boiling. Hmm ... this may be a harder challenge than I'd thought.

Production team

Day Three

Woke last night at 2.00 am feeling FOUL. Screaming headache that painkillers wouldn't touch. Lay awake for hours in agony. Stomach's gone bananas too - seems like food poisoning.

As soon as I heard Ellen open her door, I hauled her into my room. Just not capable of getting up and out. Shaky, fevery, weak and very pathetic.

I talk to a few of the others, give some instructions and hope I'll feel like a human being in a few hours. I've decided I need a larger funnel made of the thicker material to be sure I have a hope of boiling the water.

I manage to stagger up after a few hours, after downing litres and litres of rehydration fluids. Seriously needed salts back in me!

A huge 'funnel' solar oven had begun to take shape. We hung the jar inside, and finally after over an hour, we saw bubbles. Very, very pleased and relieved! Felt awful to have had to get others to help so much - but thought I'd be more likely to survive the day (and the 'finale') by turning up later on.

The solar oven ended up working a treat and boiled water happily. Mike's two filters were harder work than we'd thought, and we needed to use a foot pump to force the liquid through (Producer's note: there wasn’t time to show the foot pump in operation on the finished programme). Theoretically, the water Ian and Ellen collected should have been fine after our treatment. I have to say though, that after starting the day off with food poisoning, I'm a touch relieved I didn't have to try it.

Mars Rover was strikingly impressive. Very exciting to be out in the desert, not able to see where it was going and not sure it would survive the terrain. Amazingly, the signal worked - it was all based on being the right pitch - and we'd screamed so much it's astonishing we didn't override it!