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Cassini Huygens Probe is Ready for Separation
Lucas.clemente writes "According to The Register, the Huygens probe has been given a clean bill of health and is ready for separation. The probe will enter the atmosphere of Saturn's moon Titan sometime around Christmas, and is expected to give us some of the most Alien landscape pictures ever taken."
Or experience some kind of shattering 'Separation'. (I hope not)
There's something stunningly cool about pictures from 'other worlds' - amazing really. I do wish we would drop the 'financial' business sense, and just go in to space because we can. Does there even need to be a valid reason beyond 'why the hell not'
The thing that's sad to me is that for the amount of money we have sunk into the shuttles and various space stations, we could already have an entire fleet of robotic explorers throughout the solar system. As part of that, we'd have developed better propulsion systems, better navigation, stunning scenery, and a wealth of scientific results. If we were to follow such a course, we'd probably even have manned interplanetary voyages sooner than wasting our money on shipping people back and forth with dead-end technologies.
So, while I agree that exploration is good in its own right, we need to apply financial sense to the effort of exploration itself, and we aren't doing that as much as we should.
True. But the ESA doesn't really have a good track history of landing probes on other celestial objects. I'm really hoping that this is successful. But if you consider that they are:
1) Landing in an environment of which we don't have a detailed understanding.
2) Landing without reconnosaince photographs (for example, the Viking probes and the Russians failed landings had orbiters that could see the surface and make an educated guess about the safety of landing there. Even more recent probes had a good idea of the geography of the area that they were landing).
3) Landing a probe that has been in space for 7 years! The longest that I know of a probe that landed on another object is 1 year for the Viking probes. There are alot of variables with space travel that don't get better with age.
4) Landing a probe in an atmosphere that at launch time had only been studied by the Voyager probes 20 years before with a brief flyby. The characteristics of the atmosphere have until recently been largely unknown. And the data is still being evaluated. As we learned with Skylab, an atmosphere can change a significant degree from launch to the operations phase (Skylab burned up prematurely due to higher solar flux resulting in the expansion of Earth's atmosphere causing increased drag of the spacestation). Could there also be a chemical reaction with the atmosphere and the spacecraft (heat shield and parachutes in particular) that would destroy its ability to land softly? How will the critical reentry window vary for this atmosphere?
5) And most importantly, trying to communicate after landing. Radiation doesn't do much good for any solid state components, but communications systems could easily have components fail (compared to other systems except the landing electronics) due to the high power used.
If ESA succeeds with this landing, it will be (IMHO) the greatest accomplishment of their space program. But if they fail, it certainly won't be suprising seeing how daunting the challenge is.
While it's true that this is a risky mission, it's a calculated risk. It's not like we could spend decades studying the surface of Titan in preparation for a landing, like Mars has been explored by telescope, when the cost of doing so would probably exceed that of the probe itself. We simply have few options besides waiting for improved technologies.
And, while the characteristics of Titan's surface are essentially unknown, the composition of the atmosphere is somewhat better understood, and Huygens is supposed to transmit data during its estimated two-hour descent. I hope that will include pictures of the surface as well (after the heat shield has been dropped). Whatever is transmitted after a successful landing will be an extra bonus, but it's not like the mission will be a complete failure if the probe drops dead on impact. The precise extent of Titan's atmosphere is probably not much of an issue; Skylab was orbiting Earth for years while Huygens will plunge directly into it in a matter of minutes, and I suppose the parachute and other mechanics are designed to react to actual descent speed of the probe, not to the timer started by Cassini three weeks earlier.
I know nothing of the physical testing this design has undergone, and I'm also curious about how the chemistry will affect Huygens' components. Still, those compounds aren't unknown on Earth, and chemical tests may very well have been performed.
You mention communication problems after landing, but one problem threatened to render the Huygens-Cassini radio link unusable if it hadn't been discovered in time to be circumvented (by changing Cassini's planned trajectory to reduce its speed relative to Titan during Huygens' descent). Let's hope there are no more such flaws waiting to be discovered, because now is probably a bit late to work around them.
Even if Huygens itself were to fail completely, Cassini will spend at least four years orbiting Saturn, and so far I find that just as exciting as waiting for January 15. Given the success of the Mars rovers, what says Cassini won't have learned a few more tricks before 2008 and have its mission extended a little?
the closest english equivalent would be "uy" as in "buy". the G would be best pronounced as in "good" not "germ" should be real easy for americans - just say "Buy guns" and replace the B with an H ;)
A probe that fails to land probably has had a failure that would ruin the rest of the mission anyways. If the probe enters the atmosphere at the wrong time (for its window) it will burn up or be deflected giving no useful data. If the probe fails to actuate its parachutes it will have a very short mission giving little useful data. If there is a failure in the parachutes themselves the probe will have a very short mission giving little useful data. In fact my points 3-5 are still completely valid and I would argue at least that point 1 is important. Very smart people worked on this probe and this gives it a reasonable probability of success. But as another poster mentioned an at-launch time unknown communications failure almost lost the ability to get data from the Huygens mission. I think it is completely reasonable to be skeptical.