Chuck Yeager could always smell the Wrong Stuff from a mile away. He never signed on with the Mercury space program despite a stellar career as a test pilot. Asked why some years ago, he said, "Let's just say I don't want to fly anything where you have to sweep the monkey crap off the seat before you sit down."

Wise man, Chuck Yeager.

In the demure diction of this week's news reports, the "waste products" of two monkeys and 24 rats have been floating free in the gravityless space shuttle Challenger.

It's not a case of anything foul hitting the proverbial fan. Nothing like that. The cages, which cost $10 million and have special lighting and feeding systems, developed cracks and allowed the pungent particles to sail from their mooring.

Do we have an etiquette dilemma?

Apprised of the atmospherical conditions by telephone, Judith Martin, also known as Miss Manners, advised, "One does not inflict one's waste products on others if one can help it."

But, she added, "I don't believe we have an etiquette problem here. We have a waste disposal problem."

Carl Sagan noted a historical precedent: "Actually, it's a very old story. There's lots of human feces and urine floating in lunar orbit from astronauts and cosmonauts."

Wearing surgical masks, smocks and gloves -- but bearing no umbrellas in weightless space -- Fred Gregory and William Thornton tried sucking the excrement out of the air with vacuum cleaners. One observer at the Johnson Space Center in Houston said Thornton looked like a "walking pigpen." Of Thornton's condition, Gregory remarked to ground control yesterday that it might "be useful to clean his clothes."

The monkeys, according to the astronauts, are having a great time wiggling and jiggling in their new-found weightlessness.

The rats may be taking a rather cavalier attitude toward the discomfort they have inflicted. They have nothing to lose. When they return to earth they will be guillotined.

The animals are aboard the craft for medical experiments in preparation for the launching of a space station in 1993. Observers are betting that pets will be barred.

Space jockey Norman Thagard spoke for the benefit of future generations: "Offhand, I don't know what else you could do other than some sort of bag that would fit over the cage."

Pending improvements in the cages, there are no plans to send elephants into space.