NASA's new Mars rover "Curiosity" to carry nuclear batteries | Hacker News Reader

NASA's new Mars rover "Curiosity" to carry nuclear batteries

mars.jpl.nasa.gov

18 pointsbalakk8 comments

http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_gen...

They've been in use for decades in everything from Soviet lighthouses to space probes including Cassini, New Horizons, both Voyagers, both (famous) Pioneers, both Viking landers, the Apollo Moon landing missions, etc, etc.

There are probably a lot of clever, new and interesting things about Curiosity, this isn't one of them.

A lot of people don't know that they were also used in pace-makers.

Right, and it's going to be much better than solar panels given that they'll be able to do science before landing and also at night! Here's why it's totally secure: http://www.floridatoday.com/article/20111121/NEWS02/31121001...

Without RTG, missions beyond Jupiter are not possible. There is the Juno probe launched recently, which runs on solar panels, but those things are pretty hefty (60m^2 surface area) and a much greater weight than an equivalent RTG.

This means limited missions up to Jupiter (or perhaps Saturn) and no further exploration of the Kuiper belt.

Some people think that these power sources are actually devices which NASA will use to 'ignite' Saturn or Jupiter into a second Sun: The Lucifer Project [1]

There exist a Skeptoid episode about this, explaining that this is impossible. [2]

"But the main reason that an RTG could not explode like a weapon is its structure. Each of Cassini's three RTGs contains 72 marshmallow-sized pellets of plutonium, each weighing about 150 grams, and each separately enclosed in iridium inside a shock-proof graphite impact shell. Four of each of these are enclosed within one of 18 separate General Purpose Heat Shell modules, each with its own separate heat shield and impact shell. Should any kind of crash or problem happen, including breaking up during a re-entry, these impact shells separate from each other and scatter.

Conversely, in order to detonate Pu-238, you need a single critical mass of solid plutonium weighing at least 10 kg. This critical mass has to be imploded with a simultaneous explosion from all sides, applying sudden pressure precisely from all angles at the same exact instant. Obviously this couldn't happen with an RTG design. Although each RTG does theoretically have enough plutonium to make up a critical mass, there isn't any way that it could all be brought together into the right shape. "

[1] http://en.wikipedia.org/wiki/Lucifer_Project [2] http://skeptoid.com/episodes/4143

I thought Pu-238 was not even fissile.

It isn't.

All plutonium isotopes can be used to make nuclear weapons [1], though Pu-238 would give big problems to weapon designers due to its intense decay heat.

[1] http://cstsp.aaas.org/files/selden.pdf

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