Steam engines in space

 作者:高矜溥     |      日期:2019-03-07 07:18:01
By Ian Sample GENTLE puffs of steam could one day propel tiny spacecraft round the cosmos, say space scientists in Beijing. Steam power would provide a green alternative to toxic fuels in miniature rocket motors. Fei Tang and his colleagues at Tsinghua University have etched water thrusters from two silicon wafers, each less than a centimetre square. One wafer has a water inlet channel and a vaporisation chamber. The other has an outlet nozzle. The two wafers were then joined together. To fire the steam rocket,