The Forgotten Huygens Experiment

jdray writes "An experiment onboard the Huygens probe didn't run as planned because someone forgot to turn it on. The team lead for the experiment has put eighteen years of his life into the project, just to watch it not happen after a seven year ride to its destination on Titan."

Comments

Re:Redundancy...

[Anonymous Coward]

David Southwood (the ESA head of science) was the one who said so - he said "That's scientists trying to screw the system. We don't have redundant systems to get more data down, we have redundant systems for redundancy." http://www.newscientist.com/channel/space/mg185248 33.700

Nothing was lost, all data is safe

[thesp]

The article isn't quite correct. A fuller description would take a while to type, so I summarise:

Two redundant radio channels were used to get data from the lander to the orbiter, which relays the data to earth. The signal for the orbiter to start listening on the high-sensitivity channel, channel A, was never given. The data was transmitted redundantly on both channels, except for images and the output of the Doppler wind speed experiment. Fortunately, all was not lost, as scientists donated radio telescope time around the earth to search directly for the A signal, despite it not being relayed via the orbiter. Thanks to this increase in sensitivity, the data acquired was good enough to fulfill all objectives of all experiments.

So everyone can relax and get one with the analysis...

Latest results from analysis

[zrq]

The Huygens team held a press conference this morning and presented some of the results of their analysis so far.

The first scientific assessments of Huygens' data were presented during a press conference at ESA head office in Paris on 21 January.

Results include:

• Geological evidence for precipitation, erosion, mechanical abrasion and other fluvial activity says that the physical processes shaping Titan are much the same as those shaping Earth
• Huygens' data provide strong evidence for liquids flowing on Titan. However, the fluid involved is methane.
• ... while many of Earth's familiar geophysical processes occur on Titan, the chemistry involved is quite different. Instead of liquid water, Titan has liquid methane. Instead of silicate rocks, Titan has frozen water ice. Instead of dirt, Titan has hydrocarbon particles settling out of the atmosphere, and instead of lava, Titanian volcanoes spew very cold ice ...

Re:D'oh

[SamSim]

Roughly five to ten O's have been omitted. Homer's trademark expression was voice actor Dan Castellaneta's interpretation "[ANNOYED GRUNT]" (which is how "D'oh!" has always been written in scripts for Simpsons episodes). It's based on the "Dooooooooooh!" from the Laurel and Hardy routines, only shortened considerably. Source

Re:D'oh

[Anonymous Coward]

The french spoken in France and elsewhere is quite modern...in small town Quebec they speak a 200-year-old variant almost...it's quite unpalatable to the french ear really.

Re:Redundancy...

[Tablizer]

Perhaps it could be illustrated as follows:

Assume a probe has the bandwidth to send a total of 8 images on two channels, 4 on each channel, on the way down. Each image will be represented by the digits 1 through 8.

With exact redundancy:

A: 1357
B: 1357

With alternating redundancy:

A: 1357
B: 2468

With exact redundency, if you receive both channels, you only get 4 total images in the end. With alternating redundancy, if both channels work, you get up to 8 images in the end. But if one fails, you still get 4, just like under exact redundancy. Thus, it seems like the better choice because you get twice as many images if both channels happen to work, but both techniques still send only 4 images if one channel fails.