Three challenges down, and by now the team are starting to look a little worse for wear - and to be honest, they’re not smelling great either. So this time their challenge is to get themselves - and their clothes - clean. 

Jonathan has to build a washing machine from scratch. It’s a task that stretches his ingenuity to the limit. His solution is a toploader made from a bucket, a bicycle wheel, some tennis balls and an old power drill. That turns out to be the easy bit - it's the electronic valves and the control system that really tax his brain cells. Will he have to head off for a launderette after all? 

Ellen helps him out by going in search of a plant that will provide the washing soap. She finds what she's looking for, yucca, but will the strange looking liquid she gets out of the plant really make clothes cleaner? 

The rest of the team attempt different ways to reduce body odour. Hermione makes a deodorant out of rocks. Things don't entirely go to plan when she has a nasty surprise with a supposedly heat-proof beaker. 

Mike sets his sights on stopping sweat by creating the same chemical that's used in most commercial antiperspirants. Using aluminium foil and household bleach he sets to work. But all he seems to succeed in doing is creating some very nasty smells. 

Lastly, Ellen makes a triple action botanical roll-on using a variety of local plants. The three deodorants are put to the test in an armpit sniff trial with Kate as the sniffer dog. For Kate this could be a particularly rough episode of Rough Science.

Clean

Kate Humble

Iain Stewart

Mine

Mountain

Kicking off the new series of Rough Science, at their high altitude base in the Rocky Mountains, the team attempt to make the old mill a little more hospitable - they’ve got to supply the rickety old building with gas and electricity. In just three days they have to use natural resources to generate their own power and produce their own gas.

With no time to waste Hermione hits the road in search of coal deposits and Mike works on a gas production system to try and extract coal gas from any coal she can bring back. Her prospecting takes her out of the mountains and in to the flatter plains to the south where, by reading the landscape, she stumbles across a natural gas seep. Methane is bubbling out of a stream bed - suggesting that coal isn’t far below the surface. Hermione eventually tracks it down late in the day in trees near-by and spends a long evening digging with Kate! 

Ellen and Jonathan try to crack the electricity problem - finding a nearby fast flowing stream to harness. By piping water down from higher up the stream they can produce enough pressure to hopefully drive a water wheel and a generator. Ellen sets to work building a dam 50 metres above where the water wheel will be - drawing her inspiration from the local beaver population. Jonathan cannibalises a bicycle wheel and using some kitchen utensils comes up with an improvised Pelton water wheel. 

By the end of day two the team have some gas, but it’s not burning very brightly and they’ve got a fast spinning water wheel but no power. With so much to still accomplish on the last day it'll be a real rush to complete the challenge before the time runs out...

Power

For this programme the team are tackling two environmental hazards: fire and pollution. 

Fire is a major hazard in the dry Colorado environment and Mike and Jonathan’s challenge is to build a carbon dioxide fire extinguisher. The basis of the extinguisher is a simple reaction of baking soda plus acid, which fizzes up to create the gas they want. 

But to make the acid they need Mike has to go out and find fool's gold and then work out how to transform it. Jonathan's task is to make the extinguisher itself. He needs to find a way to keep the components separate until needed. It's a tricky problem, but Jonathan works out a clever and elegant solution. Unfortunately, the first test goes badly wrong leaving him with less than an hour to fix it in time for the final test when they have to extinguish a blazing fire. Will the pair pull it together, or will their challenge go up in smoke? 

Meanwhile, Hermione and Ellen have an even tougher task. They have to find a way to clean up the polluted water flowing out of an old mine. The mine water is acidic and contains high levels of toxic metals and this mine run-off flows into streams and rivers killing off aquatic life. Hermione's plan is to use a rock - limestone - to neutralise the acidity. She manages to find a local source of limestone - and even proves that it works in a small scale test. But making a full size system that can cope with a continuous flow of polluted water is another matter... 

Ellen's task is to deal with the toxic metals in the water, and she harnesses the power of bacteria from a surprising source - horse manure. She builds a bioreactor hoping that once the bacteria start working they'll take the metals out of the water. But getting the system up and running in 3 days proves a very tough challenge. 

Waiting for them at the end of the test is a highly sensitive panel of judges - a group of water fleas will determine if they've made the water pure enough...

Safety

The Rough Science base this year sits on the slopes of a magnificent mountain: Mount Kendall. And for this week’s challenge the team will have the task of getting to know this peak very well, working out how high it is and how much it weighs. Not just the part we can see sticking up above the Mill, but the root of the mountain, too, right down to the bottom of the Earth's crust. 

There’s a lot of maths to combine with some canny field geology to pull this one off and Hermione and Ellen pull together a unique blend of botany and geology to try and crack the dimensions

Whilst the girls get to grips with the mountain, the boys are tasked with producing a pair of sun glasses to protect Kate from the glare of the Sun. At the altitudes they are working, the Sun is particularly glaring. Mike thinks he can make glass out of sand, but it’ll need Jonathan to build a furnace that can produce temperatures of over 1200oC for hours at a time. 

It’s not something Jonathan feels confident about, and it takes the whole of the first day to come up with a design for an oven that can get anywhere near those conditions. Even when Mike find a possible source of sand nearby, the prospect of making glass, let alone making sun-glasses still seems remote...

Back on the mountain, in a combination of tree line mapping, clay model building, good old geological mapping and weighing their rock samples the girls are close to an answer for the mass of the entire mountain – roots and all. But with all their assumptions, estimates and the general inaccuracies of a flat-out three day attempt to survey an entire mountain how close will they get to the real figure?

Fresh and spiffing after last week's cleaning challenges, our Rough Scientists are about to get all messy again. This week's challenge is to find a way to detect radioactive rocks and flammable gases. But that's not all. On day three they must explore a wet dark mine using the gas detector and a reliable light source. 

Hermione decides to make a cloud chamber using a jam jar. She hopes to see the trail of destruction caused by radioactive particles. First, though, she'll need to make some frozen carbon dioxide which involves a bit of help from Mike. But not all goes to plan... 

Mike and Ellen work on a safety lamp to detect flammable gases, which surprisingly needs a flame. Ellen sets off to make a beeswax candle using a local hive. Meanwhile Mike finds an ingenious way to use the candle flame as a gas detector using kitchen implements. Will two artfully put together sieves and some homemade beeswax candles really detect flammable gas? 

Meanwhile Jonathan sets to work on making a generator to power his rugged torch. With hundreds of coils of wire and some strong magnets, Jonathan can light a dim bulb by turning the magnets constantly. But when Jonathan tries to store energy in his torch, he runs into problems. What seemed simple becomes more and more tricky as the deadline approaches. Will Jonathan be able to get his lamp to illuminate the mine? And when they get there, what will the team find?

The Rough Science team face their final challenge. They must take a memento of the mill and send it, by air, along a valley to Kate. Mike and Hermione decide to take a silver-nitrate photograph while Ellen and Jonathan hope to make hydrogen balloons to get the image to Kate.

As silver compounds were used in early photography, Hermione hopes that some of the rock taken from the mine they explored last time will contain enough silver for their photograph. But when she casts an expert eye over the rock, Hermione can’t find any silver ore. So she decides to search for more promising rocks in an old silver mine. 

Mike’s job is to make nitric acid to react with Hermione’s silver ore and he chooses an unlikely source, horse manure. But can a combination of manure and stones produce a recognisable photograph?

If the photo does get taken, there's still the problem of delivery. Jonathan and Ellen decide to make a hydrogen balloon with a timed release mechanism. Jonathan sets about making hydrogen using bits of zinc and acid while Ellen figures out how to use the wind to their advantage. Having made a wind speed detector from an old fan and voltmeter, Ellen has to figure out how to make the photograph drop into Kate’s eagerly waiting hands. 

It's touch and go as to whether the delivery system will work - and if there's something to deliver. Join the team to discover if they end their time in Colorado with a victory - or if they're heading home defeated.

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Science challenge series in which a team of five scientists pool their knowledge in order to complete a selection of set tasks.

Clean

Seasons6

Season 6 Episodes6

Cast2

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