Abstract: Using the universe as a unique laboratory for probing the laws of physics in regimes not accessible on Earth, such as the very early universe or strong gravity fields near the event horizon of a black hole, is a new common frontier between physics and astronomy. The hard X-ray modulation telescope (HXMT) mission is the first dedicated astronomy satellite in the 2006—2010 five-year plan for space science unveiled by the National Space Administration of China. The HXMT mission will perform a wide band (1—250 keV) all-sky survey with the best sensitivity and angular resolution in the hard X-ray range as a black hole finder and cosmic hard X-ray background observer, and make sensitive pointed timing and spectral observations for studying the underlying physics processes of black holes and other compact objects. Fifteen years have passed since the submission of the HXMT proposal based on a new imaging technique. It is still a challenge for China to see if the scientific opportunity created by such a technological innovation can be finally grasped.