In the last 5 1/2 years, the Soviet Union has sent 45 cosmonauts into space where they have logged the equivalent of almost two years in Earth orbit. Not a single American astronaut has visited space in the same time span. The last Americans to fly into space were Tom Stafford, Deke Slayton and Vance Brand, who rendezvoused in earth-orbit with two Russian cosmonauts in July of 1975.

One reason the score is Soviet Union 45-United States 0 is the returnable space shuttle, now two years late and almost $1.6 billion over cost. rTonight at 11 p.m., the issues of why the shuttle is late and why it's costing so much are examined in a one-hour television special ("CBS Reports," Channel 9) that is more noteworthy for its pessimism than anything else.

"If the shuttle program works the way it's designed to work, it will be a technological feat rivaling America's visit to the moon, proof that this country can still do big things," CBS correspondent Morton Dean tells us in sepulchral tones. "If it fails, the damage will be incalculable. This is America's future in space."

Looking and sounding like he's reporting a state funeral, Dean goes on to suggest that America's future in space is glum indeed, that the space shuttle is shrouded in so many question marks that there is doubts it will even work when it goes off on its maiden flight in March. Says Dean at the start of the program: "Some space experts, including Dr. Marshall Kaplan, say there's plenty to worry about."

What Dean doesn't do for his audience is to identify Marshall Kaplan, who is a professor of aerospace engineering at Pennsylvania State University. His experience with the space program amounts to one subcontract he was given by NASA to predict the reentry path Skylab would make when it fell back to Earth in 1979. He was also a rejected astronaut candidate who once said he'd love to fly on the space shuttle.

"I don't think I want to fly the first flight," Kaplan tells Dean on the program, "because I probably know a little too much about what might go wrong."

What is wrong with the CBS broadcas is Dean's gloomy assessment of what could go wrong with the shuttle. Of course, something could go wrong with the shuttle. It is a brand-new spacecraft. Its hydrogen-fueled engines are 10 times as powerful as any jet engine ever built. Its Fiberglas heat shield is unlike anything else ever developed to prevent a spacecraft from overheating during reentry.

The program is at its best when the cameras take over and the NASA test engineers do the talking. The cameras peer into the faces of the engineers as they count down through a simulated liftoff, then fire the enormous engines on their test stand in the bayous of Mississippi. The concern and concentration of these men as they conduct a test firing of the world's most powerful engine make you feel as if you're there, witness to a little bit of technological history.

Trouble is, there isn't enough history. There isn't enough of the sweat and tears of the thousands of engineers who worked to bring the shuttle where it is today. Granted, it's two years late and way over cost, but the delays and the cost overruns are only a piece of the story. CBS has failed to tell us the rest of it.