ESA and NASDA complete successful data relay tests

Another successful inter-satellite link achieved with Artemis! After a world premiere laser link with Spot 4 in November 2001 and a relay with Envisat last month, Artemis has transmitted data from the Japanese earth observation satellite Adeos II.

ESA and NASDA, the Japanese space agency, had agreed to cooperate on a data relay service between ESA’s Artemis geostationary spacecraft and Nasda’s Adeos II in low earth orbit, using ESA’s ground station in Redu, Belgium.

In this framework, ESA and NASDA performed a series of tests from 27 to 29 March to demonstrate the system’s performance and the operational links between the Adeos II team in Tsukuba, Japan, and the Artemis Mission Control Facility in Redu, Belgium.

Two types of test have been carried out :

– A complete loop was performed as telecommand and telemetry data were transmitted using the Adeos II high and low gain S-band antenna. This test involved generating telecommands in Tsukuba, transmitting them via terrestrial lines to Redu, uplinking them in the Ka-band to Artemis and from there in the S-band to Adeos II. On the return link the Adeos II telemetry data were relayed via Artemis and Redu back to Japan.

– The second type of tests consisted of transmitting Adeos II image data in the Ka-band at a rate of 60 Mbps. The Adeos II Global Imaging Instrument provides earth observation images at 250m resolution via this link.

ESA and NASDA concluded that the tests had been successful. Full compatibility and interoperability between Artemis and Adeos II had been demonstrated. The system is now ready to provide the S- and Ka-band data relay service. This capability is expected to extend the flexibility of earth observation satellite systems.

Prior to these tests ESA and NASDA had performed a series of experiments independently: NASDA has confirmed the good performance of data relay links between Adeos II and the Japanese Data Relay satellite DRTS and ESA had demonstrated the data relay link between Artemis and Envisat.

The successful completion of the Artemis/Adeos II tests is a further demonstration of the excellent cooperation between ESA and NASDA and augurs well for its continuation.

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