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Europa: No Longer a "Should," But a "Must"

Posted by Casey Dreier

12-12-2013 19:51 CST

Topics: Jupiter's moons, Europa, Space Policy, Europa Clipper

Throughout history there are tipping points when the reasons to do something difficult become so compelling that no one can rightfully ignore them – times when we cross the threshold from "should" to "must."

Today we hit that tipping point for Europa.

This enigmatic moon of Jupiter has long called out to us with its liquid water ocean that is likely in direct contact with hot spots on a rocky core. We've all read Arthur C. Clarke's 2001 sequels – well, not all of us, but for decades both scientists and the public have felt the draw to this enigmatic moon. Confusingly, missions to explore Europa have languished in conceptual stages, never getting off the ground.

But today's announcement that the moon's liquid water ocean is likely spewing forth from large geysers on its surface changes things. Instead of a call for exploration, Europa cries out to us. It's venting its most habitable environment into space, greatly reducing the complexity needed by spacecraft to analyze its chemistry. Suddenly, we can perform initial scouting for organic molecules in Europa's oceans without the complexities of having to land and drill. That's huge.

It is rare that the universe does us a favor. This is something we shouldn't let pass us by.

NASA, with support from a number key people in Congress, has spent years studying Europa mission concepts. One, the Clipper, was the cover of our 2013 Equinox issue of The Planetary Report. The Clipper flies by Europa something like 45 times in a 3.5-year mission. This minimizes the time spent in the harsh radiation belts of Jupiter and saves a lot of fuel and time by not going into orbit around the moon. It costs half as much ($2.1 billion) as an orbiting mission would have, and would achieve nearly all of the same science.

The Europa Clipper spacecraft concept

NASA / JPL-Caltech / Michael Carroll

The Europa Clipper spacecraft concept
The Clipper spacecraft flies over the surface of Europa in this artist's rendering. NASA is currently studying this reduced-cost mission which would use at least 48 flybys to explore the moon instead of entering into orbit.

This concept is so mature that NASA could have a spacecraft ready to launch by 2021 if we started building this in FY2015. Even better, if the SLS is ready to go, it could launch the Clipper direct to Jupiter. It would arrive in less than 2 years. That's a step up from a seven-year Venus-Earth-Venus-Earth-Earth flyby sequence or whatever we'd need.

The Planetary Society released a statement today calling for the White House and Congress to support a Clipper-style concept to Europa. The White House, if it wanted, could include a request for a "new start" for this mission in their 2015 budget request that they're putting together. A Planetary Science budget of $1.5 billion a year – our recommended number – could support the Clipper, the Mars 2020 rover, and restore funding for scientific research.

If you want to see a Europa mission in your lifetime, make sure your elected officials know about it. It's time to heed this cry.

See other posts from December 2013


Or read more blog entries about: Jupiter's moons, Europa, Space Policy, Europa Clipper


Kim Craig: 12/13/2013 01:12 CST

NASA SMD should prioritize Europa Clipper as its next "new start". If that means deferring the next Discovery mission then so be it. I strongly agree with Casey; "Europa MUST be next"! It is crying out for a new mission, there is just too much yet to be learned there!

Ajith: 12/13/2013 01:35 CST

Sending a nuclear powered satellite or lander to Europa should not be under taken. Even if the risk is 'very very small'. We are already destroying our planet with 'very small risk' nuclear powered satellites and vulnerable nuclear power plants. We have no right to send such a machinery to Europa. Even though the scientists communities are keen on finding what's underneath Europa's ocean, it should wait until we invent conventionally powered batteries for such a mission ( even if that takes 100 or 200 years).

Paul McCarthy: 12/13/2013 01:41 CST

I just posted the following comment on the previous Europa blog item, before reading Casey's: "I agree with Enzo. The plumes should be confirmed, and then Science (ie, ALL of it) should massively and unitedly push for direct development of a sample-return mission in the SHORTEST possible time frame. The existence of these features would provide an amazingly serendipitous short cut to the biggest question there is, potentially "the most profound discovery we'll ever make" (Leigh's words), and what we all want to know IN OUR OWN LIFETIMES. (And for the celestial body long considered most promising). It will make little sense to go through several 30-year mission development and execution cycles simply aimed at gradually accumulating ever-finer geochemical and geophysical data to buttress the scenario! Confirm, then Go,Go,Go!" But, having read Casey's, I retract. The SLS is a must - it'll be the most useful thing it ever does! Clipper straight to Jupiter is an absolute winner and an absolute must, if the new data is confirmed (and even if it isn't!). Meanwhile work on even more sophisticated scenario's like sample return.

kert: 12/13/2013 11:17 CST

If it's such a strong must - and i think i agree - then why not re-prioritize this over other big budget items like JWST, upcoming Mars missions ?

Flechette: 12/13/2013 12:21 CST

@Ajith: I understand your sentiment, but a nuclear powered probe would not endanger any possible life forms. The nuclear generators on spacecraft are not of the same type as used for Earth based power plants like Fukishima. Power plants use a fission reactor, which can melt down and burst, whereas probes use a radio isotope generator (RTG) that simply turn heat into electricity. Aquarius (the lunar lander for Apollo 13) had a RTG that crashed into Earth during the Apollo 13 saga. Nothing got hurt.

Jonathan Ursin: 12/13/2013 01:59 CST

Yay! So exciting! The results would be amazing either way.

rcatier: 12/13/2013 07:43 CST

@Ajith: The terminology "nuclear powered" should not be used for power systems that do NOT use neutron criticality to produce external heating for steam generation, or other coolant phase change, power production. What is powering a rocket is a naturally decaying element that will be depleted at end of mission, and will not "contaminate space" - the space junk will not be "more radioactive" than many meteor fragments or moonlets naturally orbiting out there.

Paul McCarthy: 12/13/2013 11:38 CST

@Ajith and @rcatier: Especially since Europa is in a particularly high-radiation setting anyway.

David Frankis: 12/14/2013 08:59 CST

I think it's worth pointing out that this can be framed as reinforcing and restoring the priorities of the Decadal Survey, since it gave Europa (in the form of JEO) a high priority. Otherwise it comes across as "Ooh look! A shiny scientific paper! Divert billions now!" Suppose we find cryovolcanic water flowing on Titan? Would you want to upend the space program for that?

Matt Colver: 01/24/2014 09:14 CST

Why wait for SLS. You could probably use a Delta IV heavy, Atlas or team up with Europe and use an Ariane 5 to send a spacecraft to fly through the geysers of Europa. I'm 59 this year and have been waiting since I read 2001 when I was 14 for a Europa mission.

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