Two satellites destined to join China’s Beidou network successfully launched Thursday aboard a Long March 3B rocket, the first two of up to 18 new Chinese navigation craft scheduled for deployment this year.

The mission, dubbed NG-21, was the second out of three planned launches of a Cygnus spacecraft onboard a Falcon 9 rocket. Liftoff happened on Sunday, Aug. 4, at 11:02 a.m. EDT (1502 UTC).

The launch of the next crew to China’s Tiangong space station late Monday (U.S. time) added three astronauts to the population of humans in space, which reached a record number of 17 people in orbit — six Chinese citizens, five Americans, three Russians, two Saudis, and one Emirati astronaut.