The First Baby Steps to Interstellar Travel

Engineer Neil Wallace peers into a huge vacuum chamber designed to replicate - as far as possible - the conditions of space. Cryogenic pumps can be heard in the background, whistling away like tiny steam engines. Using helium gas as a coolant, they can bring down the temperature in the vacuum chamber to an incredibly chilly 20 Kelvin (-253C). The pressure, meanwhile, can drop to a millionth of an atmosphere. This laboratory in a leafy part of Hampshire is where defence and security firm Qinetiq develops and tests its ion engines - a technology that will take spacecraft to the planets, powered by the Sun