by Ryan Whitwam
February 3, 2015

from ExtremeTech Website





NASA has traditionally struggled for funding since the space race died down, but there was a nice little uptick in funding from congress in the most recent annual budget.


The space agency even got more funding that it asked for, including $100 million earmarked for the planning of a mission to Jupiter's moon Europa.


NASA now plans to request an additional $30 million to fund the preliminary study of a plan called Europa Clipper, which could be mankind's first step toward finding out if there's any life in Europa's vast subsurface oceans.

Europa is a little smaller than Earth's moon, but what lurks inside is believed to be much more interesting.


Scientists have long suspected that the network of cracks in Europa's ice sheet could indicate a large volume of water underneath, and recent analysis of magnetic field data from the Galileo probe seems to confirm there is a salty ocean down there.


Europa is far enough out in the Solar System that the Sun is unable to heat water above freezing, hence the ice sheet on the surface estimated to be 100 kilometers (62 miles) thick.

The liquid ocean scientists are so interested in is likely a result of tidal forces working on the moon as it whips around Jupiter. Europa has a highly eccentric orbit, meaning the gravitational pull of Jupiter varies over time and causes flexing inside Europa. This results in heat generation that could keep the water in a liquid state.

The holy grail of Europa exploration would be to penetrate the ice sheet and actually get a look at conditions inside that liquid reservoir.


However, the technology to do that is still decades away. That's not to say NASA isn't thinking about it. There are concept studies being performed on various robots that could conduct exploration of a subsurface ocean like the one thought to exist in Europa.


The Europa Clipper is NASA's first step, though.



This mission would build on what we learned from the Cassini mission to Saturn.


That probe has performed a number of approaches to Saturn's moon Titan, which is famous for having expansive lakes of liquid hydrocarbons and a thick atmosphere. Europa Clipper would settle into an orbit around Jupiter that allowed it to make multiple flybys of Europa at various distances.


The closest passes would be just 25 kilometers above the surface.

Based on early plans, Europa Clipper will be a larger spacecraft with two 29-foot solar panels and a main body the size of a school bus. It will be similar in scale to the Hubble Space Telescope, actually. It will carry heavy radiation shielding to protect it from the dangerous particles zipping around Jupiter's powerful magnetic field.


It will likely also carry a special double shielded "vault" where the most sensitive equipment will be housed.

There's plenty of speculation that Europa could harbor life in its icy depths - not the extinct kind. After all, we have yet to find an environment on Earth with even a tiny bit of water that doesn't have something living there.


Any life in Europa would be shielded from Jupiter's radiation by the water. The proposed NASA mission would carry out spectrographic, topographic, and magnetic studies of Europa.


Of particular interest is what causes the reddish coloration of Europa's fissures.


Is it organic material? There's only one way to find out.

Europa Clipper could become a flagship mission at NASA by next Spring, which would move it from the concept stage to active planning. Scientists believe the spacecraft could reach Jupiter by the mid-2020s if NASA continues to get funding.


The total cost is estimated at $2.2 billion.