Launch Loop Stats

2017 March 11

5700 km

length of rotor

100 km

launch path altitude

0.472 km/s

Earth rotation speed at altitude

0.9647 km²/s²

0.9647 MJ/kg

Surface to altitude energy difference

14 km/s

rotor speed at altitude, not including rotation

3 kg/m

rotor density at altitude

14.074 km/s

rotor speed at surface



rotor expansion at surface

2.985 kg/m

rotor density at surface

17e6 kg

rotor mass


estimated cost of electrical steel


cost of rotor electrical steel

1.7e15 J

460 GWh

rotor kinetic energy

≈ 5.6 days

energy use in Portland, Oregon

300 MW

"maintenance" power and losses

2600 GWh

annual maintenance energy

> 95%

incremental launch energy efficiency

1.59 km/s apogee

10.33 km/s perigee

GTO transfer orbit ( GEO at 42164 km )

9.86 km/s

launch velocity to GTO minus rotation v.

50 GJ

launch energy per tonne to GTO


WAG estimate, electricity cost


electricity cost per tonne to GTO

400 tonnes/hr

maximum launch rate

3.5e6 tonnes/year

maximum launch rate

5.9 GW

power needed for maximum launch rate

Saturn V rocket

3e6 kg

launch mass

50 tonnes

est payload to GTO

A launch loop rotor weighing as much as 6 Saturn V rockets can launch as much as those six rockets in 45 minutes. Of course, launch loop stationary mass is much larger, including power plants, floats and anchoring cables, turn around magnets, sheathing, etc., but that in turn is much smaller than the construction and power plant mass of Kennedy Space Center.

Apogee insertion motors and surface operations will cost more than the launch energy.

Assume orbiting, reusable rocket motors: if tanked propellant is launched and attached to the insertion motor prior to the payload, the cost of apogee insertion will be the cost of the fuel and tank, manufactured in very high quantities. If the loop launches 80 5 tonne packages per hour, consisting of 60 payload packages and 20 triple-fuel-tank packages, that is 50,000 fuel tanks manufactured per year, not particularly lightweight but sturdy and reliable, which should result in low prices. At 85% learning curve rates, per each, 50,000 tanks should cost 20% of the cost of 50 tanks.


Stats (last edited 2017-03-11 23:58:06 by KeithLofstrom)