12 May
2003
12 May
'03
1:51 p.m.
--- Dan Wright <dtwright(a)uiuc.edu> wrote:
chris said:
From what I remember, those probes (and most (all?) other deep space
probes, I think), use a radioisotope decay generator for power.
This is a sub-critical-mass nuclear power plant; it uses the heat
produced by a near-critical lump of plutonium to generate electricity,
rather then using fission to produce heat to produce electricity.
Exactly. Sorry for not being clearer - RTG is "Radioisotope Thermal
Generator" - It's a multi-kg sphere of plutonium with a wad of embedded
thermocouples. The plutonium just fissions and produces heat (and
neutrons) which the thermocouples turn directly (albeit inefficiently)
into heat.
They are favored for remote devices (deep space, Antarctica, etc.)
because they do not depend on sunlight. Further out than Mars (and
for ~six months out of the year on the Ice), solar cells aren't a
viable option.
The big worry is that the launch vehicle will explode or the probe will
fall to earth from a failed booster stage and scatter the contents of
the RTG over a wide swath. They are designed to take a lot of abuse,
but nobody wants to be a test case.
-ethan
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In the
case of a Voyager-class probe, with RTG-sourced power,
For the few of us on the list that are idiots (ok, fine, just for me
then), what is RTG sourced power?