While NASA doesn’t have any definite plans to send a probe to study Jupiter’s moon Europa, many planetary scientists consider the exploration of this enticing moon to be a high priority. Evidence from the Voyager and Galileo spacecraft suggests Europa contains a deep ocean of salty water under an icy outer shell. NASA is, however, helping to fund a prototype of an underwater autonomous vehicle to investigate ice covered lakes here on Earth, to demonstrate if such a vehicle could operate in an environment similar to Europa. The next test of the vehicle will take place Feb. 12-15, 2008 in Lake Mendota on the campus of the University of Wisconsin, Madison.
The Environmentally Non-Disturbing Under-ice Robotic Antarctic Explorer, also known as Endurance, will swim untethered under ice, and collect data to create three-dimensional maps of underwater environments. The probe also will look at the conditions in those environments and take samples of microbial life. Later this year, researchers plan to ship the probe to a permanently frozen lake in Antarctica for more operations. The probe is a follow-up to the Deep Phreatic Thermal Explorer, a NASA-funded project that completed a series of underwater field tests in Mexico in 2007.
“We’re using extreme environments on Earth as our laboratory,” says Peter Doran, associate professor at the University of Illinois at Chicago. “Ice-covered lakes are good, small-scale analogs to what we might find on Europa.”
Mendota Lake is only 25 meters deep, while the lake in Antarctica, West Lake Bonney is 40 meters deep. Scientists believe that Europa’s ocean could be up to 100 kilometers deep.
Hot water drills will bore a hole for Endurance to enter the water. If all goes well, the probe will be tested again in 2009.
But many hurdles remain before an underwater vehicle could possibly head to Europa. Presently, Endurance is too massive to send on interplanetary travel. Scientists will also have to come up with a way to drill through Europa’s icy crust and lower the sub safely through the ice.
And before a probe would be sent to land on Europa, many scientists feel that an orbiting spacecraft would be the best way to study the moon. The Jet Propulsion Laboratory is currently working on a concept called the Europa Explorer which would deliver a low orbit spacecraft to determine the presence (or absence) of a liquid water ocean under Europa’s ice surface. It would also map the surface and subsurface for future exploration.
Original News Sources: NASA Press Release, Washington University Press Release
..or perhaps send this probe to Enceladus?
This research is important, but I suspect it’s the next generation after a Europa lander, which itself will come at least ten years after the Europa orbiter. And that orbiter mission will challenge space technology in a significant way.
We have yet to put a spacecraft in orbit around a moon of a giant planet. The only reason Huygens was able to soft-land on Titan was because of that body’s atmosphere. And before NASA will risk a billion-dollar mission, they will want detailed maps of Europa first–something on the scale of Mars Reconaissance Orbiter.
Enceladus is a way tougher mission. An Enceladus orbiter would be the first step, and with present space technology, we have no way of slipping a probe into orbit: the moon’s gravity is too weak.
If we were going to send a mobile probe to an outer solar system moon, Titan would make sense. But again, an orbiter there would tell us a lot.
My optimistic guess would be a Europa orbiter in the late 2020’s, a lander in the 2040’s, and maybe crack the ice by 2060.
I think we could do a Titan rover by 2020, but the longer Cassini extends, the longer a Saturn follow-up of any kind will probably wait to reach the drawing board.
Todd wrote:
“… with present space technology, we have no way of slipping a probe into orbit: the moon’s gravity is too weak.”
How do you figure this? Europa is only slightly smaller than our moon and has nearly the same gravity. Furthermore, NASA successfully orbited the asteroid Eros in 2001, a body with only 0.45% the gravity of Europa.
While a probe traveling to one of the Jovian moons would certainly have far greater approach velocity than that of a Lunar orbiter, Jupiter could provide a gravity assist to slow the spacecraft, much like Venus recently did for the MESSENGER probe en route to Mercury. As best I can determine, the only possible issue is that of orbital resonances among the Jovian satellites.
Your thoughts?
Edward, thanks for responding. I meant entering Enceladus orbit is tricky
I do think a Europa orbiter is doable now. And as you suggest, a series of gravity assists from Ganymede, probably Callisto, and Europa itself to maximize fuel economy, much like the Messenger mission to Mercury would do the trick.
Eros was easier because of the similar velocities of Earth and the asteroid relative to the sun. NEAR-Shoemaker had a very slow relative approach.
Enceladus is super tricky because a Saturn orbit phase one would find any probe travelling pretty fast relative to the moon. When Cassini reaches periapsis in its elliptical orbit, it is travelling significantly faster than any moons in the neighborhood. Aiming to Enceladus for a fly-by is easy. Slowing down a possible orbiter with today’s rocket technology would be costly. Titan has the only significant gravity field in the Saturn neighborhood, but is too far away to be helpful beyond a Titan-to-Enceladus orbit.
We would need an ion-propulsion probe tweaking a Saturn orbit bit by bit, lowering the apoapsis until it matched Enceladus’ orbit. The NASA Dawn mission will test an ion engine for orbiting Ceres and Vesta, good analogues for Enceladus. If that mission succeeds, I suspect the technology may be employed for a future Saturn mission.
Seems like we should be able to figure out the technology to air-brake an orbiter/lander using Titan’s/Saturn’s/Jupiter’s atmosphere to slow it down and get it into orbit around Enceladus/Europa.
So NASA is spending all there big money on Mars? You don’t think that Europa takes prority over Mars. Hello NASA!!!! Europa has a much better chance of life than mars. Lets also send the media attention to Europa and not Mars.
Europa does not excite me as much as Mars. Microbes could exist as easily on Mars as Europa, maybe more so. Mars is so much more accessable, and is infinately more possible to land on, explore and colonize than Europa.
Europa lies too close to Jupiter’s magnetic field and absorbs too much radiation for safe human exploration.
It’s not that I don’t want to send a robot there eventually, I just think that Mars is a better option.
Any life on Mars is gonna be below the permafrost, where liquid water exists. That could be about a half mile down, maybe less (but I suspect that thermal imaging from the orbiters in service would have found good hot spots by now) and drilling down that far and then bringing a sample up for analysis-unmanned-is going to be very difficult with our current technology. In the case of Europa, once you land the thing, you melt through the ice to get into the ocean (probably a couple of miles thick) and are immedietly sheilded from the rads (it’s a robot anyways) to release a submarine. Sounds to me like Europa would be easier, but still not easier than sending a Stardust sample return through Enceladus’ geysers.
Wouldn’t we need lots more thermal imaging to even think of drilling in Europa? Because what if, below the outer shell of ice, the solid middle of the planet is spinning faster/slower, or in a different direction than the outer shell. this would make the underwater currents very swift and make an underwater mission almost impossible?
And if the ice was connected to europa, wouldn’t there be lots of places where the ice was connected to the planets middle?
Any Europa ocean probe will be a nuke and 2 miles or 20 miles thick ice to melt through wont make much of a difference. All the mass of the planet is in the mantle and core under the ocean; the mantle/core will be tidally locked to Jupiter. Most probably the ice crust sloshes around atop the mantle with a period of a few million years (not much for currents). It would be best to have an orbiter first to confirm the ocean (radar soundings) and find the thin spots, with a handful of siesmic probes dropped (later) on the surface (at high velocities) to sound out the crust, ocean, mantle, etc.
Once we have Martian presence, there will be a renewed interest in solar system research and development. I’d say that there won’t be 20 years between probes. There might not be a Europan submarine by 2050 but we’ll be well established in both gas giant systems by then. Robotically represented anyway.
I see all that discussion about Mars or Europa or Enceladus, but I think that Titan is little bit underestimated. Just imagine atmosphere pressure of around 1 bar, just comfortable for people. Ice is all around you together with methane and ethane to create fuel and water. Atmosphere is important for reachability, for braking of probes. You don’t need pressurized space suit to be there just good coat and breathing apparatus. Atmosphere is not toxic, mostly nitrogen 500 km deep, protecting from space radiation. I would like to see more missions to Titan, ending with human mission.
Dont rember the name of the location in Mexico , But I read an artical where nasa was planning to test this prototype uav in .
I want to say an underwater sink hole but what it looks like to me , is a pond maybe 50-75 yards across and Very deep . Reported one diver lost his life trying to reach the bottom . Has anyone else heard about this planed test ?
If so, know the outcome , maybe a site to go to that has info. on the findings .
thanks
Ok, maybe you clowns didn’t hear me, so here we go again:
All these worlds are yours EXCEPT Europa
ATTEMPT NO LANDING THERE!!
Use them together
Use them in peace
I feel Europa is likeliest place out side of earth to find life.
According to evolution, life on earth begin in ocean. Life may also evolved in Europa’s ocean.