NBC Television bought the exclusive U.S. TV rights to the 1980 Summer Olympics here for $87 million. and will spend close to $30 million to produced 150 hours of glossy coverage of the Games nexy July 20-Aug. 3. The network will nevertheless make a healthy profit on the deal and could reap an important bonus as well.

Like an eager pole vaulter trying to soar over a challenging height, NBC executives hope to use the unprecedented Olympic extravaganza - which almost doubles the 76 hours that ABC Sports televised from the 1976 Summer Games at Montreal, and increases considerably the prime time exposure - as a springboard to bigger and better things.

Specifically, they hope to use the Olympics, as ABC did in 1976, as a means of vaulting from last to first place in the network ratings derby. This numbers game is as competitive as the one between nations at an Olympics, but only gold medals count and a third place bronze might as well be lead.

The Olympics are considered to be of enormous value in generating late-summer viewers and previewing the new fall lineqp of shows that commonly pass for entertainment on American TV.

"There is no doubt that in television terms, as far as attracting an audience and at the same time telling that audience about the shows you will have coming up in the fall, the Olympics is very, very important," said NBC President Robert Mulholland, one of several top-level NBC executives who came to Moscow last week for the opening of Spartakiade, the Soviet sports festival that is giving broadcasters - as well as athletes - a chance to preview Olympic facilities.

NBC, decidedly an underdog initially, acquired the rights to the Moscow Games early in 1977 after a wild and almost insane auction conducted by the Soviet organizers, with the International Olympic Committee, which shares the rights money, cheering from the sidelines for ABC and CBS to keep upping the ante.

NBC finally got the Games for $35 million in rights, plus $50 million toward the construction of the Olympic broadcast center, which will become the property of the government-controlled Soviet broadcast network Gosteleradio after the Games.

Subsequently, NBC ordered $2 million in equipment and facilities at the broadcast center, which has been used for the first time - and has gotten favorable reviews - during Spartakiade.

"So far the Soviets have been very good about giving us everything we have asked for. Of course, everything costs," said Alan Baker, NBC's vice president for corporate information, recently. "They are very aware of our ability to spend."

When the Olympic deal was first made, some people in the industry were certain that NBC would never make back its investment. But it will do that, and then some.It is estimated that the total sales of commercial time on the Olympic telecasts will be around $200 million.

Demand for advertising time has been strong, and the rates have been raised four times. About 94 percent of the available commercial minutes already have been sold, at an average cost per minute of $130,000. The minimum package an advertiser may buy - just in case you wanted to flack some wares during the Olympics - is $1 million. This buys 6 1/2 minutes of time divided, at NBC's scheduling discretion, among morning, weekend afternoon, prime time and late-night telecasts.

NBC Sports currently has the equivalent of 40 people working full time on the Olympics: readying equipment, working out logistics, compilling information, filming profiles and feature pieces on athletes, preparing for the care and feeding of 660 workers and 1,100 guests of the network who will be in Moscow a year from now.

In October, a team of NBC engineers will set up in residence and start wiring the installations for $20 million worth of cameras, videotape machines, switching stations, and other equipment NBC will bring with it when it comes - and presumably take out again after the Games.

The general of this army is Don Ohlmeyer, 34, who was involved in televising five Winter and Summer Olympics for ABC before joining NBC Sports as executive producer and de facto Olympics major domo in 1977.

When Ohlmeyer took charge, NBC Sports was known primarily for its live coverage of events, but had relatively little experience in "post production" - the taping and editing of events into stylized highlight packages - because it did not have a weekly sports anthology such as ABC's "Wide World of Sports" or CBS' "Sports Spectacular."

Soviet coverage of the Spartakiade is stereotyped and rather inflexible, precisely the same for every competitor in a given event, as if directed by a computer rather than a human being.

Despite shortcomings in variety, Ohlmeyer was favorably impressed by the Soviet camerawork he saw at Spartakiade, in comparison with the tapes NBC has been critiquing for the Soviets the past 18 months in an exchange program designed to upgrade the Soviet coverage that will comprise the international feed for the Olympics.

NBC will have available all pictures originated by the Soviets' 140 cameras, but will utilize its own equipment and personnel for the vast majority of its coverage, relying on Soviet pictures only for comparatively minor events such as water polo and team handball.

NBC will have twice as many cameras in Moscow as ABC had at Montreal, and will have vastly more equipment available to it than any network has had before at an Olympics.

In addition to the cameras at all the major venues used for the sporting events, NBC will have six one-camera vans - in effect, mini-mobile units - around Moscow doing feature pieces and travelogues. NBC has told the Soviets from the outset that if news stories occur - for instance, any sort of political demonstration, a rare happening in the U.S.S.R. - it would not hesitate to put them on the air, even if the Soviets turn their cameras away.

The one means of censorship the Soviets have is the drastic last step of "pulling the plug" on NBC - that is, physically preventing the Americans from sending a signal to the transmitting satellite and on to American screens.

This is an unlikely circumstance, but it has happened before. As recently as the World Ice Hockey Champiohships here last winter, the Soviets blocked out the signal - they attributed the blackout to "technical difficulties" - when Soviet and Czechoslovakian players got into a massive fistfight. Seeing Socialist brothers bloodying each other in a free-for-all was offensive to a Soviet director, and so the plug was pulled on telecasts all over Europe.

On other occasions, Soviet broadcasters have attributed interruptions in telecasts to technicians and laborers, whom they said found it against their consciences as Soviet citizens to send transmissions that they felt put the Soviet Union in a bad light.

"We are playing in their ballpark . . . If there is something that we're doing that they find dreadfully distasteful, their option is to pull the plug and they can do that," Ohlmeyer said.

"We have alternative plans. I don't want to say any more than that because then they would cease to be alternative plans. And we need alternative plans because their pulling the plug is a very real possibility. They pulled the plug on a presidential tour will President Nixon, so who are we to say they would never pull the plug on us?" CAPTION: Picture, Wardell Gilbreath signals victory in 200 meters.