THESE ARE thin times for the nuclear power industry, but its prospects are, literally, looking up.

On earth, things have gone badly since the accident at Three Mile Island. No new nuclear plants have been ordered in the United States in a decade. The costs have gone up to the prohibitive level. So has public apprehension, although at this moment, concern over what happened at Chernobyl is competing with universal outrage over Soviet efforts to cover it up.

Even before the Ukrainian meltdown, the industry was being lashed by a tidal wave of protest from two New England states, New Hampshire and Maine, which are in a state of near-insurrection over their selection as candidates to become one of two proposed nuclear-waste dumpsites for the nation.

Nuclear power still has a few good friends on Capitol Hill. One of them, James T. Broyhill (R-N.C.), is attempting a little transfusion to the invalid by way of a bill to "reform" licensing procedures -- by making them less exacting and cutting down on public participation in the decision to build or not.

Broyhill is in a difficult position. North Carolina is a conspicuous consumer of nuclear energy and is served by five nuclear plants, three of them well within the state, two at its border with South Carolina. But Broyhill's state has made the list of possible dumpsites, and the distinction is unpopular with his constituents. So he has introduced a bill that would eliminate the proposed "eastern" dumpsite -- leaving the "western" dumpsite (in Washington, Nevada or Texas) to hold the bag for the whole country.

The agitation over the waste has increased anti-nuclear sentiment to the point where angry citizens are clamoring for the shutdown of the 98 plants now in existence. Maine anti-nukes, led by their governor, Joseph Brennan, are talking about putting their Yankee reactor to referendum once again. And New Hampshire's governor John Sununu, a nuclear booster, is hearing rumblings about a new push to block the opening of Seabrook, the country's most fiercely contested facility.

Other congressional allies, mindful of out-of-sight expenses to the industry, are striving, in the debate over the Price-Anderson Nuclear Insurance Act, a benign measure passed in palmier days, to reduce the liability of nuclear utilities to damage claims from $8 billion to $2 billion.

But amid the encircling gloom is a powerful shaft of light.

Ronald Reagan is riding to the rescue.

What operators lost on earth, they may recoup in the heavens.

Thanks to Star Wars, the industry may be on the brink of resurrection.

The scientists who are working on Reagan's illusion of a "non-nuclear" space-based defense system -- which is seen by some as a trillion-dollar shield against any arms control treaty with the Soviets -- say it could require dozens, maybe hundreds, of nuclear power plants in outer space.

It's not a new idea. It's been hovering over us since June, 196l, when the U.S. launched its first nuclear-powered satellite. Forty-five have been sent up by us and the Soviets since then. A discouraging number of them, nine, in fact, have fallen down.

But the Reagan administration is going at it with great zeal and optimism and is launching a program called "Sp-100," which would cost $900 million over the next five years. Working in concert, the Department of Energy, NASA and the Defense Department are planning to orbit little nuclear factories, which would ride aloft in a shuttle and provide "steady, reliable" power for all sorts of devices and fantasies that are designed to repel, one way or another, incoming Soviet missiles.

Rep. Edward J. Markey (D-Mass.), the most conspicuous opponent of nuclear weapons and nuclear power on Capitol Hill, thinks it's a crazy idea. He challenges DOE officials who tell him that we have to go forward -- not, mind you, because we want to deploy Star Wars but only because we must meet a "threat assessment" of what the Soviets are doing to the heavens.

Markey suggests that a comprehensive test ban treaty, which is anathema for the administration, would eliminate the need for pressing forward with this extravagant nonsense.

But the DOE maintains that Soviet research would continue even under a verifiable comprehensive test-ban, although they do not trouble to explain how this could be the case.

Obviously if you are going to launch potential Three Mile Islands and Chernobyls over the world's head, you must not only do a great deal of testing, but you must persuade a great many people who don't fancy having the skies rain down radioactivity.

Maybe when people stop talking about the repulsive Soviet handling of the Chernobyl crisis, they will go back to pondering the real question about nuclear power, which is simply: Is it too dangerous? Or any less dangerous when it is 100 miles up than when it's next door?