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Twin Robots Scope Out Titanic, Europa Next?
jmichaelg writes "Wired is running an article on a pair of submersible robots that work in tandem to film underwater scenes. One robot illuminates a scene by placing the light source as close as possible to the object being filmed while the other bot manuevers for the best camera angle. That, and a host of other innovations, makes the pair significantly different than the equipment used when the Titanic was originally filmed. Significant enough that JPL has expressed an interest in using the technology to swim in Europa's seas. How JPL will overcome the time delay isn't mentioned but it's an interesting read nonetheless."
In 2008, NASA is currently planning to launch a probe to the Jupiter system called the Europa Orbiter. Its objectives are to determine the presence of or the absence of an Europan subsurface ocean, to find out where exactly is this ocean and to understand how the surface features formed. The Europa Orbiter will also find candidate-landing sites for missions to Europa's surface.
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The gravitational field probe on Galileo measured Europa to be "mostly rock, with an outer shell of water about 60 miles thick." Other instruments gave readings that supported oceans under Europa's surface. The near-IR spectrometer found evidence of salts and sulfuric acid that came out of cracks on the ice. The magnetometer reported changes in Europa's magnetic field which scientists say to resemble a salty liquid ocean.
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We will not likely go to Europa in the near future. However, we should go there.
Europa has probably the best prospeacts for life anywhere in the solar system. It most likely has a liquid ocean underneath the ice, warmed by the tidal effects of Jupiter. Deep sea vents would emit chemicals that could start life. Some people think now that life on earth may have started near deep-sea vents.
We would probably get there using nuclear propulsion if we were using a probe. Nuclear-thermal propulsion has around twice the specific impulse of conventional chemical rockets. When the probe gets to Europa, it will send down a small submersible. It will burrow through the thick ice by melting it with radioisotopes.
For a manned mission to Europa and the Jovian system, which may happen in maybe 60 years, we would probably use VASIMR engines. These are plasma rocket engines under development that would get around 30,000 seconds, or 60 times the efficiency of conventional rockets. They work by using magnetic fields to accelerate high-temperature hydrogen plasma.
VASIMR is so efficient that it would allow slow intersteller missions with 1-2% C.
For interplanetary missions, it would allow missions to Mars in about 2 months and missions to Jupiter lasting a year. Also, upon return to earth, the VASIMR ships can just be refueled and resupplied and sent on their way for very cheap.
Also, VASIMR's have some power. They have more power than ion engines.
For interplanetary missions, we really need an inexpensive space plane, like the X 34. That would slash launch costs.
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No, no and no.
Radio/radar have nothing to do with it. Nor does a "still hot core." Any body the size of Europa would have cooled by now, even with radiactive heat. (Mars, being much larger, is also largely cooled.)
We are pretty sure that there is a liquid ocean because 1) The pattern of cracks imaged on the surface. 2) The types of surface features, which are generally held to be consistent with a liquid ocean under the ice. And 3) the Galileo magnetometer measurements of an induced magnetic field, indicating a lquid interior. Modelling indicates that the field is only consistent with a liquid near the surface, not the in the core.
The heat needed to keep the water liquid comes from tidal flexing due to the forced eccentricity of Europa's orbit, unlike the usual situation for rocky bodies
NASA is already making sure that they do not contaminate Mars/Europa/etc with probes. In fact, they have been thinking about that since 1999. Check out http://centauri.larc.nasa.gov/outerplanets/Europa_ PPR.pdf for a rather laborious read.
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Solar sail, Microbots stuffed into a small capsule, and you could get to Europa at very fast speeds.
u g99_1.htm
Solar Sails at 150,000 mph, which is far faster than nuclear
Nuclear also has heat problems, and sure it can
Solar Sail
See how it works http://science.nasa.gov/newhome/headlines/prop19a
Also we could use Mini-Magnetospheric Plasma Propulsion
Plasma or ionized gas is trapped on the magnetic field lines generated onboard, and this plasma inflates the magnetic field much like hot air in a balloon.
See prototype
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"How about, the speed of sound is slowed underwater, therefore isn't a viable option for what they are trying to do."
Erm, I may be wrong - GCSE physics was a long time ago - but isn't sound faster underwater because it's more dense? I think they're just saying that sound can't provide the bandwidth for video at any decent framerate.
Maran
As a signatory to the Outer Space Treaty, the United States is obliged to ". . . pursue studies of outer space, including the moon and other celestial bodies . . . so as to avoid their harmful contamination. . . ". Non-contamination of Europa is already being dealt with
.If you were blocking sigs, you wouldn't have to read this.
It's a quote from the SF book '2010: Odyssey 2' by Arthur C. Clarke
Apparently you don't understand, because you got it wrong. Sound is 5x faster in water than in air. Nevertheless, sound (even underwater) doesn't have the bandwidth to carry video signals (not to mention noise, transmission loss, etc). You need radio or cable or something. That was their point.
They probably wont drill into the ice. One idea is to launch a nuclear powered heat "drill". This would simply heat up and melt into the ice. Simple and nothing to break with no moving parts like drill bits. Trouble is what happens if it crahes into the moon instead of landing like it should...
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