Permanent Human Settlement of the Earth, Space and Ocean Frontiers

Saturday, July 29, 2006

Nuke the Nukes?

I hear complaints all the time that we should be using solar panels for power all over the solar system so that we can finally get rid of the nukes. The fact is, we use solar panels for electrical power everywhere we can! Solar panels in space – while not inexpensive – are a good choice when and where we can use them. They are within the budget of most national space agencies, they are relatively light weight and they can conform to just about any geometry. And these considerations do not mention the political issues involved.
So then why do space craft use nuclear power so much?
The answer is twofold: quantity of power and mass.
When NASA launches for the outer planets beyond the asteroid belt, they use nuclear power generators. Or when space agency needs a lot of power, like the upcoming Mars Science Laboratory, they will use a nuclear power system. The nuclear sources is a lot smaller, has much less mass and can provide much more power than solar cells in these missions. Further, without nuclear power, we simply could not explore the solar system beyond the asteroid belt – there is just not enough sunlight and the spacecraft and its mass would be overwhelmingly large!