Dr. Grant Swinger, director of the Center for the Absorption of Federal Funds, is much better liked among the leaders of Washington's science agencies and its science policy community than is his creator, Daniel S. Greenberg.

Not that Greenberg is universally disliked. It's just that through his fractious, sometimes acerbic eight-page newsletter, Science & Government Report, published 20 times a year, he has become a thorn in many sides.

Though SGR has only 1,100 paid subscribers, at $185 a year, they include many of the top leaders in science policy matters in Washington, around the country and in 20 foreign countries, including the Soviet Union. The CIA has five subscriptions. Greenberg says he has seen routing slips clipped to the newsletter in some government offices that relay the publication to 25 individuals.

Outrageous statements by the White House science adviser, disruptive policy shifts at the National Science Foundation, partisan politics at the National Aeronautics and Space Administration and other developments that Greenberg finds questionable are reported in a direct, call-a-spade-a-spade style that amuses many but often enrages the principals. In the 15 years Greenberg has been publishing his newsletter, few of the "mandarins" of Big Science, as he likes to call them, have escaped his word processor.

In the most recent issue, for example, SGR reported President Reagan's naming of William R. Graham as White House science adviser, describing Graham as "a superhawk engineer who came up through weapons research and flopped in pursuit of the top job at NASA."

But when Greenberg departs from straight reporting and turns to satire, taking on the persona of Grant Swinger, few remain unamused.

Swinger, as practically everybody in the science policy world knows, is the person who got the Pan American chair endowed. It's not a Latin American studies chair but a seat on Pan Am, permanently available to members of the Center for the Absorption of Federal Funds as they fly to far-flung planning conferences.

Swinger helped create the University Program for the Comprehensive Handling and Utilization of Knowledge, known as Project UPCHUK.

And Swinger lectures frequently on topics such as how to invent a Russian threat in some obscure area so as to make one's grant application more appealing to U.S. science agencies.

"I get asked a lot whether Grant Swinger is modeled on a real person," Greenberg said during an interview at his Northwest Washington home and work place (SGR's offices are a converted second-floor bedroom). "Grant Swinger lives . . . . He's actually a dear friend but he doesn't know he's the model. He loves the bit, laughs and says, 'I don't know where you get this stuff.' "

In recent months Greenberg has devoted much of his newsletter to the plight of two scientists at the National Institutes of Health whose study of potential fraud on the part of some 35 scientists has been rejected or "sat upon" by every scientific journal to which they submitted it.

The implicated scientists were coauthors of papers that were found to be fraudulent. Although the fraud was initially ascribed entirely to one scientist, Harvard University's John R. Darsee, who admitted faking the data, the "hot" paper suggests that the presumed innocent collaborators were at least negligent in not spotting a number of internal contradictions in the phony data.

Headlining it as "The Fraud Study That's Too Hot to Publish," Greenberg obtained, through the Freedom of Information Act, copies of letters from attorneys for the implicated scientists to the journals' editors and to NIH officials.

"The publication of this article in its present form," one quoted lawyer's letter says, echoing many others, "is malicious defamation and will be treated as such . . . . This letter is notice to you and shall constitute such."

Although Greenberg's critics accuse him of wanting merely to expose science's dirty laundry, he sees his goal as something larger -- the freedom of scientists to publish their findings without lawyers obstructing the process.

"There's nothing more important," Greenberg said, "than protecting the purity of publication of science." At its best, Greenberg argues, science is a self-correcting enterprise. If evidence of fraud is concealed, science is weakened.

"What ticks me off the most is the scientific community presenting itself to the public as doing God's work and then resisting any kind of public or government scrutiny. A little higher standard is to be expected from people who accept canonization as pursuers of the pure truth."

Among Greenberg's frequent targets is the National Academy of Science, a federally chartered body of eminent scientists established by President Abraham Lincoln to advise the government, and its current president, Frank Press.

A few years ago SGR offered a two-paragraph item entitled "Dr. Press, Meet Dr. Press." The first paragraph excerpted a Press statement in December 1981, shortly after he became academy president, bemoaning the lack of real growth in federal spending for science over the previous 14 years. The second paragraph was a quote from January of the same year, when Press was still President Jimmy Carter's science adviser, boasting of "a new, all-time peak" in science spending.

Several other "mandarins," as Greenberg would call them, took the same position, suggesting that although science sometimes needs to have its pomposity deflated, and although he is a charming man in person, Greenberg's newsletter is read more for its "quick hit, cheap shot" gossip-column style than its balanced reporting on important science policy issues.

Plenty of other mandarins, however, not only praise Greenberg's work but allow their comments to be used in SGR promotional literature:

"As soon as Science & Government Report arrives on my desk, it gets my attention," said one, William D. Carey, executive officer of the American Association for the Advancement of Science. " . . . I can count on SGR to be timely, lively and usually a step in front of the breaking news."

Greenberg began his career with no particular interest in science. In the 1950s he was a journalist, working, among other places, as a police reporter for The Washington Post. To escape what he saw as a dead-end job, he took a fellowship that gave him a year on the Hill, working for freshman congressman John Brademas and the late senator Philip Hart.

Then he answered a classified ad through which Science, the premier U.S. general scientific journal, was looking for a reporter to cover political affairs affecting science. He was hired in 1961, quickly became editor of the magazine's news operation, and helped establish it as what he calls a "bumptious, unruly" chronicle of science politics.

"It was amazing," Greenberg says. "Here you had this vast scientific community that was having great sums of money bestowed on it, treated with great reverence and being taken at face value.

"Even back then, it was apparent the scientific community was not the product of an immaculate conception. There was a lot of greedy grubbing for grants. What it came down to was that science was no different from highway building or fast food franchising."

After 10 years at Science, Greenberg tired of repeated, though usually successful, battles with the magazine's parent body, the AAAS. He left to publish his own newsletter.

About 500 independent, for-profit newsletters are published in Washington, most of them dealing with government matters. But only SGR covers science policy. Aided by a network of sources at middle management levels in every government science agency and on congressional staffs, Greenberg has earned the grudging admiration of many.

Said one of the mandarins who asked not to be named, "I often don't like what I read, but I do read it religiously. I've got to know what's going on in this town.