The team set to work on the most explosive build yet – Churchill's Rocket Parachute. During the Second World War, Winston Churchill asked a secret team of scientists to come up with an ingenious way of making supply drops reach the ground quickly and on target. Troops desperately needed ammunition and equipment, and conventional parachute drops were constantly being shot down by the enemy or blown off course. What was needed was a faster, more accurate route from plane to ground. The scientists came up with the Rocket Parachute, in which three small parachutes would keep the load upright during a high-speed descent, and rockets would kick in to slowthe load down as it approached the ground. However, these retro-rocket tests ended in spectacular disaster. In some cases, the load even ended up being fired back into the air. Can the team succeed where WWII's greatest minds failed? They will only have one chance to find out whether they have got their calculations right when they drop their load from the sky. During the wartime trials, Churchill's scientists destroyed their workshop and injured members of the team. It will not be just the supply drop that the 'Beat the Ancestors’ crew needs to worry about! The blueprints Dick gives the team are based on recently declassified top-secret documents. In three days, the experts will need to make a pallet to hold the cargo, a rocket system, a trigger mechanism and a parachute. The cargo will be ammo boxes and an army-issue motorbike, which must land in a usable condition for the mission to be deemed a success. The team gets the chance to try out some small test rockets by fitting them into a simple wooden frame with bottles of water attached to it to increase the weight. When the rockets are ignited, the frame lifts up slightly, then flips over! Burn marks on the workshop floor reveal that one of the rockets did not fire – exactly the kind of situation experienced by the ancestors. As the team wrestle with t