Thread: Impact Craters
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Old 08-12-2007, 09:09 PM   #29
Greg
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Join Date: Mar 2007
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Quote:
Originally Posted by mikedelaney16 View Post
I assumed nuclear power would be the only viable choice for something so large and power hungry.
Yeah, and maybe some hugely huge capacitors. A mass driver is sort of like a microwave oven. When it's turned it, it seriously sucks power.

It's not too horrible, though. Assuming 2.5 g of constant acceleration and a muzzle velocity of 25,000 ft/sec (circular velocity in low Earth orbit), and 80% power conversion efficiency, a 100,000 pound payload would need 1,152 megawatts for 311 seconds.

To put that into perspective, let's use one of my favorite power units--hoovers.* That is the peak power output of Hoover Dam, 2.074 gigawatts.

The power requirement comes out to 0.56 hoovers.

Conclusion: The mass driver needs a dedicated power source equivalent to a fairly large industrial power plant, but only for 5 minutes at a time. Since I doubt that it would be acceptable to brown out Perth every time we launch something, we will need a new power plant. Considering the location, solar dynamic power might be a viable option.


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*Hoovers are much more applicable here than another of my favorite energy units, fudgies. A fudgie is the energy equivalent of a Death By Chocolate hot fudge sundae, 1500 kilocalories.
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