Calling all spacecraft! Calling all spacecraft! Be on the lookout for Captain Midnight! He is armed (with a high-powered uplink) and considered dangerous (by money-mad cable companies). Approach with caution, if at all!

The search continued yesterday for the mysterious Captain Midnight, notorious satellite hacker and video avenger who very late Saturday night committed a colossal stunt on Home Box Office (HBO), the nation's largest pay-TV network.

At 12:32 a.m. eastern time, just as the HBO film "The Falcon and the Snowman" was beginning -- for the umpteenth time -- the screen went suddenly black. Then came the familiar video "color bars" over which was superimposed this message: "Goodevening (as one word) HBO from Captain Midnight. $12.95 a month? No way! (Showtime/The Movie Channel, beware!)"

The silent message, seen by HBO viewers in the East and Midwest, stayed on the screen until 12:36, when HBO either overpowered the electronic interloper or he just got tired, depending on which experts you believe.

HBO wants the culprit apprehended and brought to justice. But a spokesman for the Federal Communications Commission said yesterday the FCC has notified HBO it can only pursue the sky pirate if he strikes again. "We told them to notify us if there should be a recurrence of this, and we will then attempt to track the source," the spokesman said.

The signal interference is a violation of Section 501 of the Communications Act and is punishable by a $10,000 fine and/or a year in prison, the FCC spokesman said.

Clearly the unprecedented interruption of HBO's programming was meant as a protest against the Time Inc.-owned cable network's new policy toward owners of home satellite dishes, who until earlier this year could pick up HBO's signal free of charge (HBO's programming is distributed by satellite to cable systems). Now HBO has electronically "scrambled" the signal and wants home-dish owners to buy a $395 descrambler and to pay $12.95 a month for the pay TV service.

Without the descrambler, the signal is just so much video gibberish.

Showtime/The Movie Channel plans to begin scrambling its signal on May 27, but will charge dish owners only $10.95 a month for the service. Even the Cable News Network (CNN) will be scrambled soon, but that isn't likely to cause protests in outer space.

HBO's decision to scramble has been a bull in the dish industry's china shop, causing sales of the home receiving stations to drop from a 1985 high of 60,000 a month to a current low estimated at 10,000 a month. Home dish owners are angry about the pay-cable industry's new barriers and tariffs but Saturday night's prank was the first time hostilities were conducted 22,000 miles up.

Space -- the final frontier. But this battle above the Earth is also taking place here at ground level.

"This is not something we take lightly, and clearly not something the federal government should take lightly," David Pritchard, an HBO vice president, said yesterday of the incident. Pritchard says HBO will attempt to identify and cite the offending birdnaper (a satellite is called a bird, see). He also said the protest will "not impact" on the HBO decision to scramble.

Surprisingly, Captain Midnight does not appear to be much of a hero with the 1.8 million home dish owners in the country. At least not according to Jeff Miller, executive editor of the Satellite Times magazine.

"I can't say that even a small part of me agrees with Captain Midnight," Miller said from his office in Denver. "We're very concerned that the consumer press could turn him into a Robin Hood figure. But what he did is something we have to realize is just wrong. It's something that has to be stopped."

Miller worries about the public perception of dish owners. He fears people will think their dish-owning neighbors are capable of playing Captain Midnight. "There are people who think the dishes cause cancer or sterility or what-have-you," Miller said. "If people can believe that, they can believe that one of their neighbors who owns a dish can do this to HBO. But that can't happen."

In fact, experts believe, it took enormously sophisticated equipment to beam up to HBO's satellite transponder in the sky and interrupt the signal it was feeding back to Earth. Captain Midnight would have needed 4,000 watts of power and a dish 30 to 40 feet wide, as opposed to the 6- to 8-foot home dishes, to pull off the caper.

From the way the pirate signal started to fade away and then returned, it appears that HBO tried to increase its power to overcome the interloper and that Captain Midnight then increased his power to stay on the circuit. In other words, what you had were two guys with joy sticks each trying to juice the other one out of the air -- perhaps the ultimate video game.

HBO will not comment on the technical aspects of the incident. Obviously, though, Captain Midnight may have opened up a whole new battleground in the sky with his attempt to chastise HBO. Maybe this, and not the Strategic Defense Initiative, is what deserves the nickname "Star Wars."

Or Signal Wars at the very least.

"I don't believe this individual will become a folk hero," said HBO's Pritchard. "From the home dish owner's perspective, the thing could backfire. The government has basically said, 'Yes, if you want to pick up these transmissions for free, go ahead.' That could change if they're going to turn around and interfere with an authorized signal."

Congressional hearings on satellite TV issues will resume on May 21. Martha Donovan, director of communications for the House communications subcommittee, said of Captain Midnight's stunt, "It's a strange event, indicative of the frustration some people feel." She said the issue of satellite jamming was announced as one of the topics for the upcoming hearings in a press release that went out just last week.

Until then, HBO and Showtime and who-knows-else will be on the alert for another attack from Captain Midnight. They'll be doing what the reporter in "The Thing," that science fiction chestnut, told us all to do at the end of the movie: "Keep watching the skies! Everybody, keep watching the skies!"