In fact, plasmas burn hot enough to instantly melt the metal walls of standard combustion chambers. Instead, powerful magnetic fields confine the burning fuel in a plasma rocket's combustion chamber. As a result, the burning fuel hangs suspended inside, without touching the chamber walls. The rocket would burn liquid hydrogen inside a plasma controlled by three magnetic cells. Electromagnetic tethers will only work in places with natural magnetic fields, like Earth orbit.
Sails seem to fit best with lightweight science probes to distant locales.
A Lightcraft depends, for now, on ground-based lasers. About the size of an Apollo spacecraft, the capsule should deliver 12 people into orbit. Current experiments have pushed a prototype to about 100 feet in altitude, although researchers say they could loft it higher. Sails, pushed by the solar wind or high-powered lasers, would propel the spacecraft toward its destination. Designed for robotic exploration missions, sails can vary from yards to miles wide, depending on the weight to be carried.