??????????????????????????????????????????????????????According to the announcement of China Manned Space Agency(CMSA),on Mar.29,2018, Tiangong-1 stayed at an average altitude of about 196.4 km (perigee:188.5 km; apogee:204.3 km; inclination:42.67°). The estimated reentry window is between 31 March and 2 April, Beijing time.??????????????????????????????????????????????????

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