Not quite nine years ago Neil Armstrong set foot on the moon and ushered in a new era. Little did he know what he was doing for popular music. On small step for man, one giant leap for rock'n'roll.

Since the '70s, rock has nurtured a small but influential subset called "space rock" that is only now coming to full fruition. It doesn't have its own section at Korvettes, nor is it always discernible from "electronic music" or "classical rock," but a flurry of recent releases shows it's here and growing.

Space rock is recognizable by its heavy use of synthesizers and lyrics that sometimes stretch the bounds of secular comprehension. It concentrates on sound, and the cosmic texture of the compositions has the same feel as a good episode of "Star Trek."

That deep, enveloping sound is nothing new. Todd Rundgren put some on his early Nazz albums and experimented with it in the studio with varying degrees of success. King Crimson's "In the Court of the Crimson King" often took on a spaceflight tranquility, and bands like Yes; Emerson, Lake and Palmer; and Genesis blended machines and instruments for fuller resonance.

Later, German bands like Kraftwerk and Tangerine Dream, Dutch groups Focus and Passport, and individual innovators like Brian Eno took the effects a step further, with almost totally electronic music; Eno even devised an entirely new system of producing recorded sound that David Bowie used on "Low" and "Heroes." Those extremes hav yet to catch on commercially, and the trend seems to be toward a more accessible mix of nebulous and pipular.

That mix is apparent on "U.K.," the selftitled debut album from a new band peopled by four certified musical astronauts. Eddie Jobson (electric violin, keyboards and electronics - ex-Roxy Music), John Wetton (voice and bass - ex-King Crimson), Allan Holdsworth (guitars - ex-Soft Machine) and Bill Bruford (kit drums and percussion - ex-Yes) are not to be confused with U.K. Squeeze, a British punk bank; U.K.'s music is about as far from punk as you can get.

Wetton's vocals are, not surprisingly, reminiscent of early King Crimson (Wetton was late King Crimson), and Jobson and Holdsworth produce a compelling blend of tones and colors. U.K. doesn't let its gimmickry get out of control and its pretension level - always a concern in this type of music - stays well below annoyance.

Roxy Music always mixed electricity with eccentricity, and it was guitarist Phil Manzanera who provided the power behind Bryan Ferry's quirky suaveness. Now Manzanera has formed 801 and almost simultaneously released two albums: "801 Live" and "801/Listen Now," a studio effort. "801 Live" concentrates more on arrangements than "801/Listen Now," primarily because Simon Ainley is a far stronger vocalist than anyone on the live set. "801 Live," though, features some remarkable synthesizer work by Brian Eno and Manzanera's own guitar is tastefully bizarre. The studio piece presents straight-ahead rock with shimmering harmonies and pulsing electronic backdrops. "801 Live" uses fewer people and more extended instrumental experimentation. The two albums cover 1975 through 1977 and range from the eerie lives strains of "Lagrina" to the near pop-single catchiness of "Flight 19." Like space itself, Phil Manzanera and 801 have infinite possibilities.

Speaking of space, "Go Live in Paris" is a two-record documentation of Stomu Yamashta's first major concert. Yamashta, one of music's true space captains, set his native Japan on its ear with his wild "classical" pieces and then loosed Go, his percussion-crazed jazz/rock fusion band, on the masses. This 1976 performance marked Go's first mass exposure and was carried on syndicated radio programs throughout America.

Vocalist Stevie Winwood is haunting as ever on "Crossing the Line" and "Winner/Loser," but Go is Yamashta's band and this is Yamashta's album. Klaus Schulze's synthesizers alternately mesh and mash with the guitars of Pat Thrall and guest Al Di-Meola. Yamashta's percussion plays off Michael Shrieve's drums and you sometimes feel caught in an intergalactic crossfire. Still, Yamashta can be gentle ("Solitude") and his titles ("Space Song," "Stellar," "Space Requiem") suggest worlds beyond our own, described in the flow of his music.

Other recent products also suggest that the universe is expanding. Pink Floyd's David Gilmour and U.K.'s Bill Bruford have their first solo albums. Two space-rock artists who have already achieved a modicum of mass acceptance - Alan Parsons and Peter Gabriel - recently marketed new records, as did Brian Eno and Genesis alumni Steve Hackett and Anthony Phillips. Genesis itself is bigger now than ever, and the latest albums by Yes and Emerson, Lake and Palmer sold well enough to show that their popularity hasn't waned. All in all, it doesn't seem far-fetched that, before long, the space shuttle will be a new dance.