MICROWAVE THERMAL ROCKETS
LASER THERMAL ROCKETS
Traditional rockets are marginal at launching things into orbit. Their chemical propellants do not carry enough energy (in the form of chemical bonds) to accelerate their own mass to orbit, let alone a tank and payload on top of that. As well as expelling propellant, traditional rockets also have to jettison parts (stages) as they ascend. The payload that is finally released into orbit is a tiny fraction of the rocket that lifts off from the ground.