Everybody knows how frugal the Reagan administration is but the National Aeronautics and Space Administration may have carried frugality beyond a conservative Republican's wildest dreams.

NASA took possession recently of something called Spacelab, a fully equipped laboratory developed and built by the European Space Agency, at a cost of $900 million, to fly inside the cargo bay of America's space shuttle. But while it took possession of Spacelab, NASA refused to take ownership of it because it would have had to pay an import duty of almost $17 million on it if it did.

"Spacelab has had a curious history," said one source familiar with both the European and American sides of the transaction. "It's almost as if nobody wants to own it."

First, said the source, ESA insisted on keeping ownership of Spacelab because that's the way ESA's 10 member states wanted it. That's all right with us, NASA replied, as long as ESA takes over third-party liability.

Well, ESA hesitated, that's not what we had in mind so why don't we transfer ownership of Spacelab to NASA. Wonderful, said NASA, until it learned it would have to pay an import duty of about 8 percent on the estimated Spacelab worth of almost $200 million.

"In effect, NASA refused to take ownership and that's where it stands," said the source. "ESA owns it but NASA has it."

Even though it still owns it, ESA formally turned over Spacelab to NASA at a ceremony held at the Kennedy Space Center in Florida. Said ESA's Michel Bignier: "This is a very important step for Europe, the first time it has truly been involved in manned spaceflight. The next step is the actual flight of Spacelab. We hope it will not be the end but the start."

Spacelab will fly for the first time in September, 1983, the ninth flight the space shuttle will make. It will carry 16.5 tons of scientific instruments designed and built by 70 scientists from the United States and Western Europe. Already scheduled are three more Spacelab flights through 1985, including one that will carry ultraviolet telescopes to take the first look at Halley's Comet as it begins to approach the earth.

Spacelab will be manned by two scientists, one from the United States and the other from Europe. They will enter Spacelab through a tunnel connecting the laboratory with the space shuttle's crew cabin where they will eat and sleep with the astronauts flying the shuttle.

A second Spacelab will be delivered by ESA in 1983 to NASA, which will buy the second laboratory and accept ownership. But NASA is still wrestling with a $17 million import duty on the second Spacelab, which it would rather not pay. The answer? It hopes to get Congress to pass special legislation exempting NASA from paying any import duty on something that has no earthly use or purpose.