deliver us the moon electric cables rotation engine

ln = natural logarithm of x, the 'ln' key on your calculator.Bε = efficiency with which engine converts beam power into exhaust kinetic energy (0.0 to 1.0, currently about 0.3).Bp = Beam power (watts) of either laser beam or solar energy collected.Δ v = ship's total deltaV capability (m/s).The equations for delta V and mass ratio are slightly different for a Solar Moth or Laser Thermal rocket engine: Having said that, the Mirror Steamer has an alternate solution. The seeding make the hydrogen more opaque so the blasted stuff will heat up. As always the reason for seeding is that hydrogen is more or less transparent so the laser beam will mostly pass right through without heating the hydrogen. Propellant is hydrogen seeded with alkali metal. The drawback include the fact that there is a maximum effective range you can send a worthwhile laser beam from station to spacecraft, and the fact that the spacecraft is at the mercy of whoever is controlling the laser station.

In some science fiction novels, combat 'motherships' will have batteries of lasers, used to power hordes of ultra-high acceleration missiles and/or fighter spacecraft. The reduced mass also increases the acceleration. Or the reduced mass makes for a higher mass ratio to increase the spacecraft's delta V. With the mass of the power plant not actually on the spacecraft, more mass is available for payload. Basically the propulsion system leaves the power plant at home and relies upon a laser beam instead of an incredibly long extension cord.Īs a general rule, the collector mirror of a laser thermal rocket can be much smaller than a comparable solar moth, since the laser beam probably has a higher energy density than natural sunlight. Similar to Solar Moth, but uses a stationary ground or space-station based laser instead of the sun.

Deliver us the moon electric cables rotation engine