Unfortunately, I don't think any chemical only rocket can get the cost
to GEO down to where power satellites make sense. Only 1.3% of a
Falcon Heavy makes it to GEO (19 tons out of 1440). Skylon, because it
burns air a quarter of the way to orbit, gets 6 tons out of 300 to GEO
(2%)

At high traffic rates, Falcon Heavy might get down to $1000/kg and
Skylon to $350/kg. I can imagine 3 Skylon takeoffs per hour. I cannot
imagine launching 3 Falcon Heavy per hour. If power sats must have
$100/kg to make economic sense, then neither one of them will do it.

However, using laser-heated hydrogen, a 125-ton Skylon variation can
deliver 25-30 tons to LEO and 18 tons to GEO. That's 15%. Cost is less
than doubled by the investment in lasers while payload fraction goes
up by 7-8 times.

The front-end investment is over $100 B; it makes power plants cheap
enough to sell the power at 1-2 cents per kWh. The demand is certainly
there at $1.6 B/GW, 1/5th the cost of a GW nuclear plant. Demand at
such a low cost would permit very rapid growth, to one or two TW/year.
At that rate, power sats would end human dependence on oil and coal
within two decades from the start.

Keith

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