The performance of a normal micro gravitational heat pipe was investigated using the analytical and numerical models previously developed. An innovative structure of the heat pipe, i.e. the micro gravitational heat pipe with artery, was then proposed in an attempt to overcome some of the drawbacks of the normal pipe. The thermal behaviour of the new type of heat pipe was simulated, and this was compared with that of a normal micro heat pipe. A performance estimation of both pipes was carried out based on the simulation results. Copyright (C) 2002 John Wiley Sons, Ltd.