Huygens Probe Prepares for Saturn Moon Landing

Nathan writes "A probe is about to land on one of Saturn's 35 moons, Titan. The probe is a collaboration with NASA, the European Space Agency and Italy's space program. The probe is apparently about the size of a Volkswagen Beetle. This landing should lead scientists toward new information about the atmosphere and the magnetosphere."

Not just images...

[YrWrstNtmr]

but hopefully audio as well.
From SpaceflightNow [spaceflightnow.com]
"Also among the expected post-landing data are sounds from a microphone that might capture the rustling of frigid nitrogen winds or lapping waves."

VLBI observations of Huygens' descent

[zennor]

The data transmitted by Huygens will be uploaded to the Cassini spaceprobe and then transmitted by Cassini back to Earth several times. This data will be received by the NASA DSN dishes such as that a Tidbinbilla near Canberra in Australia.

Separate to this will be a unique experimental observation organised by JIVE, the Joint Institute for VLBI in Europe that will involve 17 radio telescopes around the world including the Parkes dish in NSW. They will monitor the weak signal of the Huygens probe directly to detct any doppler shift in the signal. Using VLBI (Very Long Baseline Interferometry) astronomers hope to be able to pinpoint the entry of Huygens into Titan's atmosphere to within 1 km. As it descends under parachute they also hope to use doppler shifts to measure the speed of the wind at different levels in the atmosphere. Should be an interesting observation.

(Disclaimer; I work for one of the institutes involved in this experiment)

Re:Timeline and (better) coverage...

[Basehart]

When I watched this launch I remember wondering what I'd be doing in January 2005. It seemed like so far in the future back in 1997. Meanwhile that spaceraft has been getting further and futher away from us, travelling thousands of miles an hour, and now we're only a few hours from touchdown on a distant moon.

How totally exciting, to be here in the future :-)

Re:A sight no one has ever seen before...

[spaceyhackerlady]

What gets to me about this is the fact that we will truly be seeing something that no human being has ever seen before...

What I've thought was so cool about all of this is that they've taken IR pictures throgh the haze. They can see things, but they haven't a clue what they're looking at. Now that's cool!

I've seen Titan myself many times, but only as a tiny spark of light along for the ride with Saturn. I've seen 5 of the 35 moons through my backyard telescope.

I wish the ESA folks all the best.

...laura

Re:Umm .... mars?

[britneys 9th husband]

In other words, sending out space probes is like hitting a baseball. If you're successful four times out of ten, you're doing a great job.

Seriously though, "successful missions per billion dollars spent" is a more important metric than "successful missions per 10 missions attempted."

Re:A sight no one has ever seen before...

[andreMA]

If I recall, anything more than 30 minutes of Huygens life on the surface would be pointless because Cassini will be out of range (below the Titan horizon for Huygens) and no data can be sent back from the extra time.

Huygens NASA/ESA probe?

[drachton]

This story wrongly calls the Huygens probe a NASA/ESA/(italian spage agency?) cooperation, whereas Huygens is actually strictly the work of ESA. The Cassini-Huygens mission *is* however a NASA/ESA undertaking. I'm not trying to play down NASA's contribution, which is of course critical to the success of the whole enterprise, however since a previous slashdot story [slashdot.org] about the mission talked about "NASA's Cassini probe", I feel it's only fitting that the credit for the success (or impending failure, naturally) be given to ESA.

Variable-heat RTGs

[Sloppy]

Maybe I don't understand RTGs too well, but .. can't you just have the materials spaced far apart when it's in vaccuum, and then once the probe enters a heat-conducting medium and starts to get cold, have it use some little motor to move the the materials closer together?

Um, and then move them even closer together, really fast, if the probe is ever captured by hostile Martians and needs to self-destruct. ;-)

Or does the stuff in RTGs not decay faster when it gets neutrons sprayed at it?

Re:A sight no one has ever seen before...

[Seahawk]

Surface touchdown is at 12:34 GMT, and cassini stops receiving data at 14:44 GMT - so the probe could in theory send for 2 hours from the surface.

Huygens' carrier signal detected!

[EdibleEchidna]

According to ESA's website [esa.int]: The Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, USA, a part of the global network of radio telescopes involved in tracking the Huygens Titan probe, has detected the probe's carrier signal.

This means that the probe survived the entry (heat-shield) phase of the descent and the main parachute opened, but we still have to wait for the main part of the show...

Titan

[Antonymous Flower]

This mission is very exciting. In an introductory chemistry course one might learn of the "triple-point" of a substance. This is the point at which a substance may exist as a vapor, a liquid, or a solid. Earth's atmosphere allows for the triple-point of water which we all should know is vital to our functionality as living beings. Titan's atmosphere allows for the triple-point of methane. It is speculated that this may allow for a mechanism of life based on methane. Discovery of extraterrestrial life WILL change everything. Good Luck on your mission, gentleman. The world is with you and eager.

The probe is alive !

[mbone]

Good News from Titan !

The Great Big Telescope (officially the Robert C. Byrd Green Bank Telescope) at Green Bank, West Virginia has detected [esa.int] the carrier signal from the Huygens probe.

This means that the spacecraft is alive, has made it through re-entry, and the parachute has deployed.

A total of 17 radio telescopes here on Earth are tracking [esa.int] the Huygens probe, using a technique called Very Long Baseline Interferometry, or VLBI [nasa.gov]. Using phase referenced VLBI, it should be possible to track the Huygens descent to within about a kilometer on Titan, and to get descent velocities to within a few millimeters / second along the line of site. This will give us a pretty good idea of the winds that the probe encounters as it descends, and also should really nail down the rotation of Titan if the probe makes it to the surface. Here [www.oan.es] is a more detailed description (pdf file) of what's being done using VLBI from Leonid Gurvits.

While this does not mean that the Huygens mission is a full success (I personally want pictures from the surface!), it does mean that some scientific data will be returned. I can't wait to see more.