ESA transmits first-ever telecommands to Chinese satellite

PRESS RELEASE
Date Released: Tuesday, November 13, 2007
Source: European Space Agency

For the first time, ESA tracking stations have transmitted telecommands to a Chinese satellite. This morning at 07:15 CET (06:15 UTC), China's mission control reported that commands transmitted from Maspalomas station had been successfully received by the Chang'e-1 Moon mission.

ESA ground tracking support to China's Chang'e-1 successfully started on 1 November 2007 at 04:35 CET (03:35 UTC) with the first receipt of telemetry signals from the Chinese mission at ESA's 35m deep-space station at New Norcia, Australia.

Two hours and 39 minutes later, the first telecommands to Chang'e-1 were transmitted via ESA's 15m station in Maspalomas, Spain, when the Chinese satellite was nearly 200 000 km from Maspalomas station. An hour later, the ESA station in Kourou, French Guiana, also successfully received telemetry and transmitted commands to Chang'e-1.

New Norcia, Maspalomas and Kourou stations are part of ESA's ESTRACK ground station network, and are remotely controlled from the European Space Operations Centre (ESOC), in Darmstadt, Germany.

The successful communications mark a major milestone as this is the first time a telecommand to a Chinese spacecraft has been transmitted from an ESA station. In addition to receipt of telemetry and transmission of telecommands, the Maspalomas and Kourou stations also performed ranging and Doppler measurements used to determine the spacecraft's location and direction.

"The support began as planned and without any problems. We were confident it would work given the extensive preparations and intensive testing we did in close cooperation with the Chinese," said Erik Soerensen, Head of the System Requirements and Validation Section at ESOC.

Time-line to success

This morning, engineers working in ESOC's ESTRACK Control Centre reported the following series of events (times in CET = UTC+1):

04:35 ESA's 35m New Norcia station successfully acquired Chang'e-1 telemetry

05:15 Beijing Aerospace Control Centre (BACC) successfully connected to New Norcia via ESOC

05:15 BACC reported receipt of good telemetry Marks the first time that an ESA station has received, processed and routed telemetry signals to a Chinese control centre

05:44 ESA's Maspalomas station successfully acquired Chang'e-1 telemetry signals 06:50 BACC successfully connected to Maspalomas and reported good telemetry

07:04 Maspalomas successfully established the up-link to Chang'e-1 and BACC reported on-board lock 07:14 Telecommands from BACC successfully transmitted from Maspalomas

07:15 BACC reported telecommands successfully received by Chang'e-1