Posted on 06/25/2015 8:28:21 AM PDT by BenLurkin
In just a few short weeks, NASA’s New Horizons spacecraft will make its historic flyby of Pluto and its moons. Solar panels are unable to operate in the dim nether regions of the outer solar system, and instead, New Horizons employs something that every spacecraft that has thus far ventured beyond Jupiter has carried in its tool kit: a plutonium-powered Radioisotope Thermoelectric Generator, or RTG.
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One of the first spacecraft that sported an RTG was the Transit-4A satellite launched on June 29th, 1961. Another similar satellite in the series, Transit-5BN-3, was lost shortly after launch along with its plutonium-fueled RTG, which reentered over the Indian Ocean. The
Soviet satellite Kosmos 954 also reentered over the Canadian high Arctic in early 1978 along with its onboard nuclear reactor.
And when Apollo 13 returned to Earth, the crew jettisoned the Aquarius lunar landing module over the Pacific, where it reentered along with its plutonium RTG meant for the ALSEP experiments that the Apollo astronauts placed on the Moon during every mission.
... NASA estimated a catastrophic launch failure involving an RTG rupture during the New Horizons launch at 1-in-360. ...
A nuclear RTG works by utilizing the waste heat generated by the radioactive decay of plutonium-238. This not only has a half-life of 87.7 years, but it also generates a very respectable 560 watts of energy per kilogram per second. Unfortunately, the stuff we weaponize for nuclear bombs is a separate isotope known as Pu-239, and it can’t be repurposed for RTG use. The production of plutonium-239 for nuclear weapons during the Cold War did, however, also assure that the capability to also create Pu-238 for spaceflight was on hand until production was ended in the United States in 1989.
(Excerpt) Read more at universetoday.com ...
Don’t worry about the plutonium shortage. Iran will fill the gap, though I imagine they’ll charge high prices.
A nuclear RTG works by utilizing the waste heat generated by the radioactive decay of plutonium-238. This not only has a half-life of 87.7 years, but it also generates a very respectable 560 watts of energy per kilogram per second [...]
Sigh!
A watt is not a unit of energy, but rather of power. And a Radioisotope Thermoelectric Generator (RTG) is already nuclear - so there's no need to repeat that word in describing one.
To be brief: An RTG produces 560 watts of power per kg.
Regards,
To be briefer: An RTG produces 560 watts per kg.
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