Launch was expected December 9 at 03:26 UTC from the Taiyuan Space Centre. It would have put CBERS 3 into a sun-synchronous orbit with its Descending Node at 10:30 local time. Because of the Brazil involvement, organisations in that country were the main sources for the launch date/time information.
The CZ-4B launch vehicle took off on time and the launch appeared to go well. In fact everything seemed normal enough for the Brazilian National Space Reseach, INPE (Instituto Nacional de Pesquisas Espaciais), to announce success. The INPE announcement appeared within thirty minutes of launch and began to filter out to mainstream news organisations. The timing was a little quicker than is usual for Chinese space missions where the interval between launch and acknowledgment is usually around one hour.
The earliness was not unexpected because of Brazil’s interest in the launch through being a partner in the satellite. INPE’s press release said that the launch had gone well, the satellite parted company with the rocket using a system of springs after 12.5 minutes as expected and it was in orbit. The INPE press release contained no other information.
A pointer to a possible problem with the launch came in the silence from China.
About five hours after launch, stories started to appear on Brazilian news websites that all was not well and the launch had failed. Reports quoted INPE as confirming that separation was as planned and that the solar panel on CBERS had opened. However, none of the expected radio transmissions from CBERS were detected as it proceeded round its orbit.
By that time, experience says that the first orbital data should have been coming out of US Space Command through the SpaceTrack website but that source was silent too.
Seven hours after lift-off a statement came from China, through the state Xinhua news agency, formally confirming what was already known. Referring to the satellite by its Chinese name of Ziyuan 1-03, it quoted a military spokesman as saying that the rocket malfunctioned during the flight, and the satellite failed to enter orbit. An investigation was said to be under way to determine the cause.
A parallel statement from INPE re-iterated that CBERS 3 had reached space but said it had then fallen back to Earth. From other directions, but attributed to INPE, came information that radio transmissions from CBERS 3 had been detected for fifteen minutes after it separated from the rocket. It was said to have fallen in the region of Antarctica.
The reported fifteen minutes of radio reception is interesting as it runs through to L+27.5 minutes when CBERS 3 would have been well away from China and out of view from mainland tracking stations. The Yuanwang 6 tracking ship is reported to have been on station in the Indian Ocean to monitor the launch. L+27.5 minutes would have been about the time it expected to lose signal from CBERS 3, and probably also the launch vehicle, as it headed along a track that took it over the south pole.
The tracking ship may have collected sufficient information to determine what happened. It will be interesting to know whether everything can be passed back through radio communication channels or whether it will have to wait for the ship to return to a port.
On the surface, it has the hallmarks of a failure in the launch vehicle’s third stage. A first or second stage issue would have occurred while the rocket was still over China and, potentially, the launch vehicle destruct sytem could have been activated.
More likely, the third stage failed to impart sufficient speed either by being low on thrust or shutting down early. A timer system probably released the satellite at a pre-determined moment. It must have reached orbit altitude and then fallen back because of the low velocity.
The shortfall could have been quite small. CBERS 3 would have been in an orbit with perigee inside the atmosphere or even below the Earth’s surface. The result was an inevitable destructive re-entry with the tracking ship standing by helplessly observing it.