In his 21 years at the ticklish business of naming new astronomical discoveries, Harold Masursky has resolved countless delicate quandaries of cosmic diplomacy. But assigning names to the newly found moons of Uranus may prove the stickiest challenge of his career.

Masursky, a GS15 astrogeologist with the U.S. Geological Survey here, will preside over the June meeting of the international Working Group on Planetary System Nomenclature, where the new moons and hundreds of other celestial features recently discovered near Uranus by the Voyager space probe will be named.

As president of the 10-nation nomenclature group, Masursky has been inundated with letters, pleas, petitions and official resolutions from fellow Americans asking that seven of the new Uranian moons be named for the astronauts who died Jan. 28 in the explosion of the space shuttle Challenger.

Unfortunately, Masursky says, the non-American majority on the nomenclature committee seems reluctant to go along.

"It would be a total break with tradition," Masursky said. "There's a lot of precedent for naming moon or planet craters after people. But moons! You see, we have always given moons literary or mythological names."

As a further obstacle, the nomenclature group has a "waiting period" rule dictating that no Earthling can be honored with celestial appellation until at least three years after death.

This moratorium was waived in the case of the prominent Soviet scientist Msitislav V. Keldysh, who received an eponymous moon crater within months of his earthly demise, and presumably it could be ignored again.

In an informal conversation with Masursky, a Soviet member of the nomenclature group has proposed honoring some of the Challenger astronauts, but not with Uranian moons. That plan calls for two craters on Venus to be named for the two female members of the Challenger crew.

This comports with nominal precedent, because all the features of Venus have been named after women (among other things, there's a crater on Venus named "Sacajawea," the Shoshoni Indian who guided the explorers Lewis and Clarke on their way to the Pacific Coast). But Masursky said it is not clear whether the Soviets proposed this honor instead of or in addition to the moons of Uranus.

Meanwhile, a British observer, Sara Herschel Dunkerly, has filed a strong appeal asking the committee to name the newly found moons in "traditional" fashion. Her request may carry weight because she is the great-great-great-granddaughter of William Herschel, discoverer of Uranus.

"All in all, it could be a difficult question to settle," sighs Masursky, a precise, witty Yale-trained geologist whose cosmically cluttered office at the USGS station here is decorated with a globe of the Earth's moon, an Altimetric Shaded Relief Map of Venus and a huge color photo of a Marscape bearing the label "East Mangala Proposed Mars Landing Site."

"There's no question we'll honor the Challenger astronauts," Masursky said. "The only question is what's the best way . . . . This requires a great deal of diplomacy. What I've learned after many years is that it's very difficult to have a dispassionate discussion of names. People get totally irrational. They get hysterically angry."

Sometimes nomenclatural disputes can be resolved with finesse.

A few years back the Soviet members of the nomenclature group wanted to name moon craters after the workers' collective that builds Soviet space rockets.

"We didn't want to give them a direct no, because we must have their cooperation in this business," Masursky recalls. "So we said, 'Fine, you do that, and we'll put Martin Marietta and Rockwell on the moon.' And then they withdrew their proposal."

To soothe the Soviets, the international group did permit a moon crater to be named Mare Moscoviensis -- Lake Moscow -- even though most lunar seas bear the names of emotions, such as Tranquility Bay. At all costs, the working group wants to avoid a dispute such as the one surrounding a moon of Jupiter discovered eight years ago. The French astronomer who found the moon wanted to name it "Janus," but the working group "had many bitter arguments about that" over three years, Masurky said. "The problem was, the name was proposed by a Frenchman, and many people in the profession don't like this Frenchman."

Further exploration revealed that the moon tentatively named "Janus" was two satellites, and one was permitted to remain "Janus" on the celestial charts.

The Janus dispute points up an issue in the naming of the 10 new moons of Uranus, which have been given the temporary names 1985U1 and 1986U1 through 1986U9 pending the international nomenclature group's June meeting.

"Before you put a name on a satellite, you have to make sure it's really there -- not just some noise i.e., electronic static in the transmission from Voyager," Masursky said. "And you need to establish an orbit to make sure it's only one moon."

Over the next two months, a commission of the International Astronomical Union is expected to certify that the moons photographed by Voyager are real. Because their discovery of the moons came just days before the Challenger tragedy, Americans by the thousands have been lobbying Masursky to name them for the seven astronauts who died.

Bridge clubs, Brownie troops, corporate chieftains and both houses of Congress have sent petitions. "We're getting letters from all sorts of weird administrative bodies," Masursky said. "They say, 'The commissioners of this or that water board or soil district respectfully urge. . . . ' "

The intense U.S. campaign to honor the astronauts with Uranian moons has made little impression on non-American members of the nomenclature group, said Masursky, who has been conducting informal telephone polls on the question since the first mail bags showed up six weeks ago.

The five previously known moons of Uranus carry names of characters in English literature. Three are from Shakespeare: Titania, Oberon and Miranda; two are named for Arieal and Umbriel, the light and dark spirits in Alexander Pope's "The Rape of the Lock." Anticipating that more Uranian moons would be found, the nomenclature working group has compiled a list of names of Shakespearian dramatis personae.

If that makes the moons of Uranus unlikely repositories of astronautical appellation, what honors will the Challenger crew receive when the nomenclature group meets in Toulouse, France, late in June? One idea floating around the world astrogeology community is to give the astronauts' names to asteroids, which are sun-orbiting bodies somewhat smaller than planets. Masursky demurs. "The asteroids don't strike the right note. There are thousands of them out there."

But the most likely alternative, Masursky said, is a plan that will adhere to nomenclatural tradition while recognizing the coincidental link between the Uranus discoveries and the Challenger accident. It calls for giving the astronauts' names to seven big craters on Miranda, a Uranian moon named for a character in Shakespeare's "The Tempest."

The newly found Uranian moons, after all, are "just dots of light in a crowded picture," Masursky said. The craters of Miranda, in contrast, are "important features of an important body that will be the subject of fascinating study."

While Miranda's craters may seem eminently logical to astrogeologists, the proposal has received a lukewarm political reception. Rep. Bill Nelson (D-Fla.), who sponsored a congressional resolution asking the nomenclature committee name the moons for the astronauts, said he would "have to object to the crater alternative."

Nelson said, "The cause is so strong, we think those traditional rules should be set aside."