WIRED Science offers an update to one of the many substances the planet risks depleting – plutonium-238. This has been a problem since at least 2009. While the government has finally restarted production of that isotope (one that is very difficult to use for nuclear weapons production) after a 25-year absence, it will take some time to replenish the supply. At current capacity the expectation is production of three pounds per year. The country currently has 36 pounds left.
The scarcity of the plutonium comes into play when the requirements of deep space explorers are taken into account. NASA has used radioisotope generators to power its spacecraft since the Voyager craft left the earth in the late 1970s. As the spacecraft energy demands fluctuate, so will the demand on the plutonium. For instance, the power plant behind the rover Opportunity requires roughly 10 pounds of it. NASA personnel estimate that with current plans for missions, the plutonium-238 supply will disappear by the end of the decade.
The restarting of production is just a first step. There needs to be at least one more production facility, and that seems to be far from a done deal. Upcoming mission cuts may be seen as responding to budget pressures, but a dearth of fuel is as much of a constraint.
Hopefully readers of this blog may pick up on a theme, with challenges in securing sufficient supplies of helium, medical isotopes, plutonium-238 and other critical elements. Some of the critical ‘high-technology’ issues are hidden. They are embedded in other things and processes that we come to accept as commonplace. Unfortunately, when we stop seeing these hidden things, we forget about what it takes to make them in the first place. And that makes it much harder to make them again.