View Single Post
  #2  
Old April 7th 17, 10:11 AM posted to sci.space.policy
William Mook[_2_]
external usenet poster
 
Posts: 3,840
Default Reusable Laser Launcher

On Thursday, April 6, 2017 at 2:10:06 PM UTC+12, William Mook wrote:
A 50.0 MW laser beam energising a rocket with a jet power of 35.7 MW produces a laser energised rocket to create a 20,572 mph exhaust jet from inert material like water. This jet produces 1,741 pounds of thrust lifting a vehicle that weighs 1,358 pounds at lift off. 1,100 pounds (132 US gallons) contained in a sphere 39 inches in diameter, is energised over 12 minutes to boost the 330 pound payload to orbit aboard the 311 pound vehicle. After one orbit, the booster derbies and descends back at the launch centre, landing under laser power, 84 minutes after launch. Within 120 minutes after launch the booster is ready to go again!

Payload 330 pounds
Structure 311 pounds
Propellant 1,100 pounds (water)


A satellite at an altitude of 250 miles the satellite rises 1371.3 mile on one side of the laser and sets 1371.3 miles on the other side, arcing across the sky in 9 minutes 16.3 seconds.

The laser has 9 minutes to energise the rocket for a deep space boost! Boosting a 330 pounds vehicle from 17,665 mph to 23,373 mph - puts it on course to the moon by adding a 6,708 mph delta vee. At 4 gees, it takes 75 seconds to accelerate from 17,665 mph to 23,373 mph, and covers 437.9 miles during the acceleration boost!

With a 20,571.4 mph exhaust speed 92.8 pounds of propellant is required to accelerate to that speed. 238.2 pounds sent to the vicinity of the moon.