Space.com (October 14, 2009)
"One of NASA's next great adventures could take place with a raindrop-flecked camera bobbing around on extraterrestrial waves. Or at least, that's the hope of several researchers who want to sail an unmanned, nuclear-powered capsule on Saturn's moon Titan.
"Titan eerily resembles Earth with characteristics such as wind, rain and lakes, but all within the bounds of a frigid environment where methane and ethane replace liquid water. The many lakes dotting the moon's surface suggested an alternative mission proposal compared to the usual rovers and hard surface landers that NASA has sent to other destinations.
" 'We got funded to look at the possibility of sending a lake lander to Titan,' said Ellen Stofan, a geologist with Proxemy Research in Maryland. 'Scientifically, it's sort of a beyond obvious thing to do.'..."
On radar maps, quite a lot of Titan's northern hemisphere, above around 60° latitude looks like the lake country, north of my home here in Minnesota. The 'water' there is most likely hydrocarbons and the temperature averages around -292 degrees Fahrenheit or -180 Celsius: substantially colder than a Minnesota winter.
Still, the article says that two of Titan's lakes are about the size of North America's Great Lakes or Eurasia's Black Sea: big enough to be quite certain of landing a probe in the lake, and not on the surrounding land.
Sure, the lake's 'water' is ethane and/or methane; and really cold: but it's liquid. Which is much easier to land - safely - in than solid ground. That's why America landed its pre-shuttle spacecraft in water - and the former Soviet Union and now Russia probably would have, except that Russia is frustratingly short on usable seaports.
The roboship - if it gets funded - would probably be powered by an ASRG - Advanced Stirling Radioisotope Generator.
Horrors! Was That "Radioisotope"?!!
Yeah: a (shudder) nuclear reactor.Sort of. The things use heat from nuclear decay - not actual fission. The heat runs a piston which in turn runs an electrical generator. Compact, fairly efficient, and the new generators use about a quarter of the plutonium needed by earlier models.
Why the (shudder)? Well, as anybody who's seen "Godzilla" and "The Swarm" knows, nuclear anything is pretty much awful and dangerous and shouldn't ever be used because something dreadful will happen. (The Lemming is lazy today: I used the same two movies in this blog's last post.)
If the Titan lake lander gets launched, I'm pretty sure there will be the usual protesters with signs. I'm concerned about the (remote) possibility of plutonium getting dropped, if something goes wrong during launch. But I also recognize that life is inherently risky: and that the benefit/risk ratio in this case seems very favorable.
But then, I'm rather of the 'follow knowledge like a sinking star, beyond the utmost bounds of human thought' sort. I like knowledge.
And dangerous pollution is nothing new.
Smog Blows Away - - -
Before internal combustion engines replaced horses as a power source for vehicles, cities like London had pollution problems that'd give your standard-issue environmentalist activist fits. For good reason: I've shoveled enough of the stuff, myself - and it's no picnic to handle, even for someone without much of a sense of smell.Great Science; Doable Technology; Funding Could be a Problem
The lake lander mission may never get off the ground. NASA has a finite budget and may not give the go-ahead for the project.Which will be a bit of a disappointment, but hardly the end of the road for landing a buoy in Titan's lakes.
It'll take a while for private-sector efforts to get the vehicle inventory and investors for a project like that, but my guess that even if NASA abandoned Saturn-system exploration entirely, my children - or their children - would see the launch of a non-government robotic expedition to Titan. (October 4, 2009)
Think Jacques Cousteau and the Calypso in space.
Cool Maps
(NASA/JPL, via Space.com, used w/o permission)
(NASA/JPL, used w/o permission)
"Titan's North Polar Region"
(October 11, 2007)
"This Cassini false-color mosaic shows all synthetic-aperture radar images to date of Titan's north polar region. Approximately 60 percent of Titan's north polar region, above 60 degrees north latitude, is now mapped with radar. About 14 percent of the mapped region is covered by what is interpreted as liquid hydrocarbon lakes.
"Features appearing darkest to the radar, which are thought to be liquid, are shown in blue and black, and the radar-bright areas likely to be solid surface are tinted brown. The terrain in the top center of this mosaic is imaged at lower resolution than the remainder of the image...."
(NASA/JPL)
Vaguely related posts:
- "When it's Time to Build Spaceships, People Will Build Spaceships"
(October 4, 2009) - "Two Decades Later: Voyager 1 Flyby of Triton, August 21, 1989"
(August 21, 2009) - "Atomic Science Set"
(March 30, 2009) - "Futurists Through the Centuries"
(November 1, 2007)
No comments:
Post a Comment