Now,

imagine a 200 GW laser power satellite on orbit. It has the capacity
to beam energy to the upper stage of the vehicle just described. Now
imagine that a second stage engine is equipped to receive laser energy
from space, sufficient to produce 339,556 metric tons of thrust by
heating 167 metric tons of hydrogen per second - to exhaust it at 20
km/sec.

This requires the power 33 TW of laser energy - the output of 167
power satellites.

The second stage is equipped with a stretched second stage hydrogen
tank with a 16.84 meter spacer between spherical end caps, which is
filledwith 129,644 metric tons of hydrogen in the 105.55 m long
stretched tank. the base of the second stage is the same, but has a
16.84 m long 88.71 m diameter cylinder inserted mid way through the
stage, before narrowing to a 64.61 meter at the top - with a 112.81
meter base.

This vehicle delivers 102,658 metric tons to GEO - using the same
booster and an improved upper stage.

A stretched deep space stage is attached to the top of this two stage
booster. The deep space stage is a stretched version of the third
stage which is capable of landing on the moon and returning to Earth -
with 20,000 tons of payload. The vehicle is also capable of executing
a powered touchdown on Mars and returning to Earth - again with 20,000
tons of payload.

A laser propelled version of this vehicle is capable of flying to the
asteroid belt, surveying to find rich feedstock for human industry,
and attaching laser powered rockets that use the asteroid itself as
propellant.