'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. ®
..they should give Iran a call.
Essentially, yes. Pu-238 only makes up a few percent of the plutonium output of a normal reactor - too little to make extraction practical. And military reactors are more interested in Pu-239 (Pu-238 is too stable to sustain a chain reaction). Therefore, the only way to produce it is through neutron bombardment of Neptunium-237(itself an expensive-to-extract reactor byproduct). After the US fell out of love with nuclear power, the demand for radioisotopic generators dropped so precipitously that it wasn't worth producing the stuff any more. That and the fact that the US hasn't actually been in the business of reprocessing waste nuclear fuel for some years.
I know a supplier...
I'm sure that there is a new manufacturer in the Middle East just itching to prove that it can supply uranium 238 in large quantities to the US. There may be some haggling over delivery mechanisms and scheduling that need to be worked out.