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Original URL: http://www.theregister.co.uk/2010/01/13/plutonium_pinch/

'Plutonium pinch' nips NASA

Shortage of fuel squeezes exploration programme

By Lester Haines

Posted in Science, 13th January 2010 11:50 GMT

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NASA's future solar system exploration programme could be threatened by a shortage of plutonium-238, New Scientist reports [1].

Many of the agency's spacecraft rely on the nuclear fuel, but the US no longer produces the stuff, and despite previous estimates that the lack of plutonium-238 wouldn't bite until 2020, NASA is "already tightening its belt".

While missions such as Juno [2] - slated to depart for Jupiter in 2011 - will rely on substantial solar arrays for power, this technology isn't suitable for more distant destinations "or even darkened regions closer to the sun, like the polar regions of Mars".*

Jim Green, head of NASA's planetary science division, told NS: "Without the plutonium, there's just a huge dimension of science we're going to be missing."

One programme already feeling the "plutonium pinch" is New Horizons, which recently announced [3] three contenders for a 2018 mission to either the Moon, Venus or an asteroid. One of the criteria for candidate spacecraft is that they be solar-powered.

While the US Department of Energy is "currently analysing what will be required to restart plutonium-238 production", it won't be able to supply the fuel required for NASA's proposed Europa Jupiter System Mission [4] in time for its slated 2020 lift-off.

Accordingly, NS says NASA will rely on supplies bought from Russia to fuel its Jupiter Europa Orbiter's radio-isotope power source.

The National Academies Press has a detailed report on the US's plutonium-238 supply situation and the need for radio-isotope power sources here [5]. ®

Bootnote

* To a point. NASA's Phoenix lander [6], which operated until November 2008 in the Red Planet's arctic region, is solar-powered, although the Martian winter appears to have killed it [7].