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For the project of the Laser Time Transfer (LTT) we have developed the photon counting detector package designed to synchronize the ground and space based clocks by laser pulses. The device flying modules were constructed at the Shanghai Observatory, China, and they were tested for operation in a space environment in 2006. Numerous ground indoor tests of time synchronization of the rubidium clock were performed before the satellite launch. The device was launched onboard the Chinese experimental navigation satellite Compass-M1 on 13 April 2007 to a high altitude orbit of 21,500 km. The world's first space clock synchronization by means of laser pulses was carried out from the satellite laser station Changchun, Jilin, China, 1 August 2007. The results of the space born detector package pre-launch tests along with the first in-flight operation results are presented.