Modular Laser Launch Systems

BerntB writes "I don't think Jordin Kare's NIAC article has been covered? It's about using new laser tech to build modular laser launch systems. The modular nature makes it easier to test and build. The only other launch ideas as cool are the Orion Project and the space elevator."

Comments

How Ironic...

[Baldrson]

The only other launch ideas as cool are the Orion Project and the space elevator.

Since the prior story is about Carnegie Mellon its rather ironic that the most intriguing launch technology was left off entirely -- and it is out of the robotics department of CM: the Rotovar(tm) by Hans Moravec.

We investigate a cheaper system. A satellite in low circular equatorial orbit has two long cables extending in opposite directions. It rotates in the orbital plane, and the cables touch the planet each rotation, with the rotational velocity canceling the orbital velocity. The system acts like two spokes of a giant wheel rolling on the equator.

The orbit is stable, and the taper is minimized when the satellite's diameter is one third the planet's. On Earth it is 4000 km long and touches down every 20 minutes, every 2 hours at six points. Cable motion near the ground is vertical and uniformly accelerated at 1.4 g. The maximum velocity in the atmosphere is 2 km/sec. One eighth the strength of graphite gives it a taper of 10:1, and it can lift 1/54 of its own mass at each contact.

The central idea in this paper, of a satellite that rolls like a wheel, was originated and suggested to me by John McCarthy of Stanford. He also encouraged the work and provided many of the resources for it. The symbolic mathematics was done with the MACSYMA system being developed at MIT. This program behaves like a programmable desk calculator that deals with algebraic expressions instead of simply numbers. It is capable of solving equations, integrating formulas, taking limits and much more.