Pre-launch information also said that the broadcast would be transmitted using new space infrastructure that was completed in July 2012. This is a reference to the constellation of Tianlian data relay satellites in geosynchronous orbit, the third of which was launched 2012 July. They provide communications links between satellites in orbit and their control centres in China. The space lesson was timed to match a period when Tiangong 1 was in continuous view from the Tianlian 1A satellite stationed at 77° east longitude.

June 18, China's Ministry of Education issued a directive requiring local education departments to ensure all schools and colleges prepare their pupils and students to watch the lecture June 20 between 10:04 and 10:55 local time. It was broadcast live from Tiangong 1 and commenced at 10:10 (02:10 UTC). It can be seen in its entirety in this recording from CCTV, China's national broadcaster, with an English translation.

On the map, the yellow line is the ground track of Tiangong 1 on June 20 between 02:04 and 02:55 UTC. The two white arcs are the limits of visibility from Tianlian 1A of satellites orbiting at Tiangong 1's altitude.

Tianlian saw Tiangong appear from behind the Earth, to its west, at 02:04 UTC. With the lesson set to start at 02:10 UTC, it provided the control centre and schools about six minutes to establish the communications link and settle down before the broadcast went live. The broadcast ended before Tiangong reached Tianlian's eastern horizon.

NOTE - One of zarya.info's Twitter followers, Teny Zhu, pointed out that, for a little over five minutes as Tiangong passed above China, the transmission was carried via the Qashi, Dongfeng (near Jiuquan) and Weinan ground stations. It switched quickly between them as can be seen in the CNTV video. The name of the receiving satellite or tracking station is shown at the top right hand corner of the screen partly obscured by the TV station overlay saying "Live". The switching can be detected through slight discontinuities in timing during the video caused by the longer the distance travelled by the signal when carried via Tianlian 1A.