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A NASA spacecraft arrived at the planet Jupiter yesterday. The Juno mission will spend over a year studying the gas giant. Enjoy it while it lasts because as NPR's Nell Greenfieldboyce reports, NASA's exploration of the solar system is about to hit a real slump.
NELL GREENFIELDBOYCE, BYLINE: Right now there's only two space probes orbiting planets in the outer solar system - Juno around Jupiter and a spacecraft called Cassini around Saturn. Within the next couple years, both will be gone. They're slated to plunge into the gas giants and burn up. Casey Dreier is Director of Space Policy at The Planetary Society, a group that promotes space exploration.
CASEY DREIER: It'll be the first time since the 1970s that there will be no NASA presence in the outer planets. For the first time in 40 years, the lights will go out in the outer solar system.
GREENFIELDBOYCE: Oh, NASA does have stuff going on closer to home. In September, one mission will go off to an asteroid and return a sample to Earth. And there's a couple of missions that will go back to Mars. But besides that, there's nothing planned for a while.
DREIER: So there is a real precipice that we are approaching.
GREENFIELDBOYCE: Usually NASA has one or two launches a year, so what's going on? Jason Barnes chairs the Division for Planetary Sciences of the American Astronomical Society.
JASON BARNES: Basically we're suffering now from what were budget cuts to the planetary budget that started in 2013 with the sequester.
GREENFIELDBOYCE: Remember the sequester, those automatic cuts imposed by Congress? NASA's Planetary Science budget got slashed by about 20 percent. Managers scrambled to save missions that were already underway. Barnes says almost all planning for future missions got put off.
BARNES: No missions were able to get started during that sort of 2013 to 2015 period.
GREENFIELDBOYCE: So NASA is now trying to whip up some new adventures, and Congress is getting involved here, too. Lawmakers recently ordered NASA to visit an icy moon of Jupiter. This moon called Europa may have vast underground oceans. That makes it an intriguing place to look for life. The Planetary Society's Casey Dreier says last year's Appropriations Act requires NASA to launch a Europa mission by 2022.
DREIER: People kind of jokingly refer to it as the only mission that would be illegal for NASA not to fly.
GREENFIELDBOYCE: Now, the law doesn't just say, go there. It says, go there on a certain rocket, one that Congress demanded NASA build after the retirement of the space shuttles. Jim Green runs Planetary Science at NASA.
JIM GREEN: It's the most powerful rocket humans have ever built. It will take astronauts to Mars.
GREENFIELDBOYCE: Critics have argued that this massive rocket is too expensive and won't fly astronauts often enough to make sense. So if this rocket needs more missions...
GREEN: Launching unmanned probes, particularly to the outer part of our solar system, might indeed be a good thing for everyone.
GREENFIELDBOYCE: Places out there like Europa might be good targets because this big rocket can get there in under three years instead of the usual seven or eight. So Green is happy to obey the law.
GREEN: I'm delighted to say we're going to Europa, OK? Whether, you know, the law helps us there or not, our plan has always been to go to Europa at some time or another.
GREENFIELDBOYCE: There's other places in the outer solar system they'd like to go, too, like Saturn's moon Titan which has lakes of liquid methane and another moon, Enceladus, which clearly has an underground store of water.
GREEN: We see geysers coming out of the Southern Hemisphere.
GREENFIELDBOYCE: Green says early next year NASA will put out a call for new mission proposals. Both Titan and Enceladus are on the list of possible destinations. Nell Greenfieldboyce, NPR News.
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