Spacelab experiment. Astronaut Gregory Linteris conducts an experiment into combustion in microgravity in the Spacelab module aboard the shuttle Columbia. He is preparing a 35 millimetre camera, one of the three photographic systems used to record the Drop Combustion Experiment (DCE). The DCE apparatus includes an enclosed chamber in which mixtures of helium and oxygen are injected to be burnt as single droplets. Combustion of fuel droplets is an important part of the operation of internal combustion engines, gas turbines and home heating systems. Photographed during mission STS-83 (4-8 April 1997).