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Huygens on Titan

Huygens, now on the surface of Titan, has been transmitting data for five hours now, twice the expected time. Signals received by the Parkes Observatory in Australia first confirmed that the probe had survived the landing. It has also been confirmed that at least one experiment — the Doppler Wind Experiment — has been successful.

Update: Cassini has turned toward Earth and is now transmitting Huygens data, with about forty minutes of preliminaries before the crucial science data are sent. ESA scientists should start looking at the first datasets around 1130 EST.

The key question remains: how sound are the data? From John Noble Wilford’s story on the New York Times Web site (free registration required):

The possibility remains that a design flaw in Cassini’s radio receiver system will hopelessly scramble the data. Engineers anticipated that signals from the wind-tossed Huygens would vary widely in frequency and strength, and thus compensated for it in the receiver’s design. But they had failed to take into account frequency shifts that would also throw off the timing of the encoded data, leaving it a garbled mess.

In early 2000, an ESA engineer recognized the problem. Finally, ESA and NASA engineers found a way to reduce the frequency shifts to acceptable levels by altering the trajectory and orientation of Cassini during the critical maneuvers.