Aircraft, one of the biggest carbon dioxide producers worldwide, do not have a viable alternative. Electric aircraft are slow and extremely short range. Hydrogen powered aircraft have a more normal range but require specialized equipment while still remaining slow and expensive. Synthetic aviation biofuels do exist but are significantly more expensive that fossil fuels. Instead these aircraft can be powered by microwave beamed power from solar power satellites.

Solar power satellites are designed to capture solar energy in space, before it is diluted by the atmosphere, then beam it down to in flight aircraft using microwave beams. The receiver will consist of an array of dipole antennas connected to simple rectifier circuits. Actual beam trajectory will be monitored by measuring voltage at several points on the receiving network of antennas. This data combined with the aircrafts known location and velocity vectors will be used by a closed loop control system.

Initially aircraft will be retrofitted with a flexible film that is applied to the top of the wings and fuselage, and motors that are installed in the aircraft’s engines. Eventually turbofans could be replaced with other engine types that are significantly simpler, further driving down air travel costs.

The first few solar power satellites will be produced on earth, but eventually they could be produced in space from material harvested from asteroids, kick starting space colonization while reducing the dependence on fossil fuels.

This implementation has a very good demonstrated history of technical feasibility. Solar power satellites were first proposed in Isaac Asimov’s short story Reason. It was demonstrated that power beaming is feasible with cavity magnetrons. Unfortunately, it was discovered that solar power satellites were too expensive and too risky to compete with traditional ground based power plants, one of the cheapest sources of energy in any form known to man. There was even an attempt at using microwave beamed power with drone aircraft in 1987 but was canceled when fuel prices fell.

Aircraft retrofitted with this system will have nearly infinite aircraft range limited only by crew fatigue. On takeoff over 50% of a long range aircrafts weight is fuel, allowing a significantly larger fuel capacity. This will mean that transoceanic flight tickets will fall from thousands of dollars to hundreds of dollars. This will in turn cause a major rise in tourism worldwide. In addition to passenger and cargo aircraft this system can be fitted to military aircraft decreasing their reliance on tankers and increasing their combat radius.