Original URL: http://www.theregister.co.uk/2010/01/13/plutonium_pinch/
'Plutonium pinch' nips NASA
Shortage of fuel squeezes exploration programme
NASA's future solar system exploration programme could be threatened by a shortage of plutonium-238, New Scientist reports.
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 - 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 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 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. ®