Huygens!
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It's not as bad as it sounds. They said there are two channels as a safety device in case one failed. It seems that one channel did fail, but both relay the same information so nothing will be lost.
By the way I just realised that when they say 'tonight' they're on European time, so us folks in the Americas may be able to see the results by this afternoon. Yay!
By the way I just realised that when they say 'tonight' they're on European time, so us folks in the Americas may be able to see the results by this afternoon. Yay!
Re: Data vs carrier signal
Harry wrote:AFAIK this was never planned. It's just a way to quickly check that Huygens is/was alive.andersa wrote:I thought the idea was to use radio telescopes on Earth to try to pick up the faint Huygens data signal as a backup measure just in case the there were still problems with the Cassini relay operation
The carrier signal is also analyzed using interferometry, to determine the precise descent path of Huygens through the atmosphere. I wasn't aware of this experiment until recently, so I guess I must have misread something about it earlier in connection with the Cassini relay doppler problem, thinking the radio telescopes were for data backup.
I also watched the ESA press conference (via NASA TV webcast) where Huygens mission manager Lebreton explained they had been surprised by reports from Australia that Huygens just continued transmitting, and they were now busy requesting time on radio telescopes also in Europe to continue receiving the signal as Saturn rises in the night sky (Saturn is currently in opposition). The batteries on Huygens are told to last for up to seven hours under optimal conditions, which means they have probably run out by now.
There were several questions from the press about the redundancy of the data channels. As I understand it, the carrier signal from the A channel was supposed to be used to obtain additional interferometry data. That opportunity may now have been lost, if the A channel failed as has been indicated. While all instruments onboard have been made to deliver their data via both A and B channels, they haven't spent valuable time transmitting every picture twice, but instead twice as many pictures, half of which may now be lost. Given that they will largely show the same piece of ground, this is hardly a disaster, just less redundancy in the data.
First pictures are expected to be made public around 19:45 GMT (11:45am PST).
Anders Andersson
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The webcast is up and running again.
Last edited by The Singing Badger on 14.01.2005, 20:00, edited 1 time in total.
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- Posts: 125
- Joined: 18.12.2003
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- Location: Canada
Where did you see this, Badger?
...I'm also interested in the sound files, if any, that Huygens recorded. Did we get any audio recordings with the data?
NASA TV is apparently slashdotted (or shatters.netted, to coin a phrase) and this link keeps timing out, but I think it's the best bet anyway.
http://spaceflightnow.com/cassini/050114pic1.html
OR try
http://www.astrobio.net/news/modules.ph ... _photo.php
Cheers,
Joe
http://spaceflightnow.com/cassini/050114pic1.html
OR try
http://www.astrobio.net/news/modules.ph ... _photo.php
Cheers,
Joe
Last edited by alphap1us on 14.01.2005, 20:18, edited 1 time in total.
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- Posts: 125
- Joined: 18.12.2003
- With us: 20 years 11 months
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- Posts: 125
- Joined: 18.12.2003
- With us: 20 years 11 months
- Location: Canada
I was somewhat annoyed to tune in to the broadcast expecting to see images from Titan and instead to see mainly images of ESA VIPs giving their predictable reactions to the achievement. But at least they did show one image (and I think they may also have inadvertantly shown another for a few seconds). It was enough to indicate that the imaging experiment was successful, so we can relax about that now. And hopefully they'll be willing to show us a few more images in a little while.
- Hank
- Hank
I wonder if there is any data coming in beyond what Cassini relayed. I think I read that since the probe lasted at least 2 hours longer than its three minute surface life span, that Earth radio telescopes would be attempting to receive the data that Cassini is unable to receive?
Is Huygens still active as of now, does anyone know?
Is Huygens still active as of now, does anyone know?
"To make an apple pie from scratch, you must first create the universe..."
--Carl Sagan
--Carl Sagan
lot's of raw data:
http://www.lpl.arizona.edu/~kholso/data.htm
http://www.lpl.arizona.edu/~kholso/data.htm