Tsinghua-1 is the first demonstrator for the Disaster Monitoring Constellation and carries multi-spectral Earth imaging cameras providing 39-meter nadir ground resolution in 3 spectral bands. The Disaster Monitoring Constellation, being led by Surrey for launch in early 2002, will comprise five microsatellites able to provide daily world-wide high resolution imaging for the monitoring and mitigation of natural and man-made disasters. The Chinese Tsinghua-1 satellite will also carry out research in low Earth orbit using digital store-and-forward communications, a digital signal processing (DSP) experiment, a Surrey-built GPS space receiver and a new 3-axis microsatellite attitude control experiment. Tsinghua-1 utilize three reaction wheels to provide full 3-axis agility on a microsatellite platform. Ten engineers and scientists from Tsinghua University have spent 12 months during 1998-99 at the Surrey Space Center - working alongside SSTL engineers on the design, construction and test of the advanced microsatellite.