A combination of manure and stones produce a recognizable photograph.
In order to safely explore a dark, wet mine, the team must find a way to detect radioactive rocks.
The challenge for the team is for the members to get themselves and their clothes clean.
How high and how much the peak weighs.
Two environmental hazards: fire and pollution.
At their high altitude base in the Rocky Mountains, the team attempts to supply the old mill with gas and electricity.
The scientists must build an underwater breathing device.
The scientists must invent a system that can alert boats that they are entering a coral reef area.
The team's challenge is to build a lighthouse on the tiny island of Bawe, which is covered by dense tropical forest and has no electricity.
The team's challenge is to find a way of eavesdropping on the sounds of the reef.
The team's task is to prepare Kate for being lost at sea, providing her with a distress flare, a life jacket and a beacon.
Scientists mount an expedition to find a shipwreck off Zanzibar's west coast.
Mike Bullivant, Jonathan Hare and Kathy Sykes try to build three different rockets using water as fuel; launching a raw egg and returning it safely to earth.
Designing an aerial surveyor; locating the epicenter of California's huge 1872 earthquake; making a carbon dioxide filter.
The team is challenged to measure a giant crater and determine the size of a meteor.
The team is challenged to design a cooling system for a spacesuit.
Carrying a voice on a sunbeam; the botanists try to invent a zero-gravity pen; plaque for deep space.
The scientists must make a rover, then find water and purify it.
The teams builds a furnace to smelt and forms gold into souvenirs.
Extracting gold from rock and sand; building an altimeter and using it to find buried gold from a treasure map.
Measuring the speed and melt of the Franz Josef Glacier.
The team makes a waterproof tent and a seismograph using alarm clocks to measure earthquake activity.
The team builds an automated gold-panning machine.
Five scientists try to collect gold from a river.
The challenge is to create a concert and spectacle to light up the sky.
The challenge is to build an underwater light to examine marine life.
Thermometers and sunscreen are part of the assignment to lower the effects of the island's heat.
The island's resources help the five tackle a transmitter, a portable clock and a botanical kite.
The scientists try to construct a biology lab, microscope and weather station within three days, using a basic tool kit and the island's plants.
The team of scientists must make a scale map, botanical paper and ink, and a sound-recording device to chart the sites and sounds of the tropical island.
The scientists grow food, make soap and use seaweed, shells and mint for toothpaste.
The group races to generate power; pharmacy of natural potions.
Using sea water, seaweed and urine, the scientists construct a camera and film, a compass, and dye for a flag.
The scientists try to find their latitude and longitude, make an insect repellent and construct a radio from a saucepan.
The team must build a lighthouse so that the research vessel can navigate to shore.
Communicating without the use of sound waves.