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Huygens 5th checkout successfully completed during night of 2 February

Huygens 5th checkout successfully completed during night of 2 February

The fifth in-flight Huygens checkout was successfully completed during the night of 2 to 3 February. The Probe was switched on at 23:00 UTC on 2 February and switched off at 02:50 UTC on 3 February. The data came down with a 25 min delay due to the propagation time of the radio signal from Cassini/Huygens to the Earth. The telemetry data were made available to the Huygens Flight Operations Team at HPOC at ESOC in Darmstadt (D). A preliminary evaluation of the data by the Flight Operations Team indicates that all subsystems and experiments performed as expected.

Earth seen from Cassini-Huygens

The receiver AGC values were expected with some excitement as this was the first checkout to be performed with the HGA turned away from the Sun. The team were in for a nice surprise. The AGC values were even higher than the values obtained during the special off-Sun test performed in May 1998. The values varied between about -92 and -94 dBm.

The Probe and the Probe Support Equipment (PSE) have been switched off to let them cool down. The Probe will now sleep until the next regular checkout scheduled in early September 2000. The PSE will be switched on tomorrow again for the Probe S-band relay test. The Huygens flight control team has prepared the data for distribution to the principal investigators for a detailed analysis. We expect to provide a complete preliminary report within two days.

Probe S-band relay test

Now that the Probe checkout has been completed, over the next two nights a sequence of Probe S-band relay tests will be conducted to exercise and calibrate the Huygens radio receivers on board the Orbiter. The S-band relay test will be performed by transmitting from the Goldstone DSN an S-band signal (2.040 and 2.098 GHz) to the Orbiter's HGA. The Probe itself will remain OFF during the Relay test. The Huygens Probe Support Equipment - the piece of Huygens equipment that remains permanently attached to the Orbiter after the Probe release - will see this signal and process it as if it were coming from the Probe itself during its descent in through Titan's atmosphere. This will provide a complete end-to-end test of the radio link between the Probe and the Orbiter.


Last Update: 1 September 2019
21-Sep-2021 23:49 UT

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