The solar power satelline suggested as a cure for Earth's energy ills would heat up the ionosphere to the point of jamming most of the world's police and citizens band radio transmissions.
That's the tentative conclusion of scientists at the National Astronomy and Atmospheric Center in Arecibo, Puerto Rico, where experiments with the world's biggest radio telescope have beamed microwave signals up into the ionosphere the same way a solar power satellite would beam them down from 22.400 miles in space.
"What people were afraid might happen really does happen," said Dr. Frank D. Drake, professor of astronomy at Cornell University and director of the Arecibo Observatory. "When the beam goes through, the temperature of the ionosphere goes up 20 or 30 percent and radio waves get reflected that are normally not reflected by the ionosphere."
Radio waves not normally reflected by the ionosphere include the frequencies used by citizens band and police radio. They also include taxi radios, which transmit on frequencies that don't get scattered by the ionosphere and tend to stay in the same localities from where they're transmitted.
These local radio transmissions would be beamed halfway across the United States if they were reflected by the ionosphere. Police radio from metropolitan Washington could be heard in Kansas City. Truck drivers in California could be listening to CB transmissions from truck drivers in New Jersey.
"You get too many transmissions, is what happens. Everbody jams everyboday else," Drake said the other day. "Every taxicab radio will be heard in every taxicab radio in Amercia."
The solar power satellite is a brainchild of Arthur D. Little scientist Peter Glaser, who has said that for $10 billion the United States could orbit an array of mirrors and solar cells that could convert solar energy to microwave energy for continuously beaming up to 5 million kilowatts of electricity power plant can create 1 million kilowatts continuously.
Spending for the SPS so far is what's called "study" money. The National Aeronautics and Space Administration is only studying the concept, with no firm plans to orbit any solar mirrors.
The radio telescope at Arecibo found that the microwave beam heated and expanded the layers of gas and charged particles that makeup the ionosphere at an altitude betwen 50 and 200 miles.
Once the ionosphere expands, the electrons in the ionosphere start to bunch up like sausages along Earth's lines of magnetic force. The "sausages" of electrons are dense enough to reflect radio waves not usually reflected - CB, police and taxicab transmissions.
The scientists at Areciobo want to be super-sure their first experiments were right, so they plan to repeat them in the next six months using a larger transmitter to generate more heating of the ionosphere. Explains Drake: "We want to duplicate more closely what the solar power satellite would do."