Solicitation Number: BAA07-65 Notice Type:

(Keith wrote)

>130 W/kg isn't very favorable for power satellites.
What is?
For penny a kWh, the total cost can't be more than ~$850/kW. For two cents, $1700 kW. That's based on a ten year payoff from electricity sales.

So the product of kg/kW and $/kg to GEO needs to be in the $500-1000/kW For 5 kg/kW (which Phil Chapman thinks doable) that means transport cost of $100-200 per kg.

This is measured in space, about 7.7kg/kW. You have to double this for the ground figure because of a 50% electrical to electrical transmission loss. So for a power satellite this would be about 15kg/kW, which would need transport cost down in the $30-70 per kg range.

That's possible. Using a Skylon or similar vehicle for the first 4 km/sec and a figure of a million dollars per flight delivering a 25 ton payload to GEO the chemical part would cost $40/kg. This takes a mass ratio three, 300 tonne vehicle, 200 tonnes propellant, 50 tonnes structure and a 50 tonne mass ratio 2 laser stage. The laser stage would need 8 GW to power it. At $10/watt, and a ten year write off, that would cost $8 billion per year. But it would be lifting 100 tonnes/hr so in a year it would lift 800,000,000 kg or 0.8 billion kg. So the cost per kg for the laser part of the lift would be $10 for a total of $50.

Still, the profit margins would be thin and there is not much room of anything to go wrong at this kg/kW performance.
Wasn't there solitications in the 1980s that wanted about 10-100x that?
I don't remember what the proposed performance was. I do remember that Boeing designed a single module, one with 4 then one with 16. I don't think they ever figured out why the smaller unit designs worked better. See the box on page 6 here: http://www.nss.org/settlement/L5news/L5news/L5news7907.pdf for why.

Keith
David

This is released information. I had a hard time opening it, but was
able to read it through Google.

130 W/kg isn't very favorable for power satellites.

Keith