Inner Space.

That's astronaut John Young, pondering the 1981 launch of Space Shuttle Columbia. But artist Henry Casselli left Young and the shuttle out of his title, instead calling the watercolor, "When Thoughts Turn Inward," thus making it a narrative work. Narrative paintings--they imply a story that the viewer must imagine--haven't had much status since Queen Victoria was buying them. Casselli's work is currently touring the country as part of an exhibit of NASA-sponsored paintings called "The Artistry of Space"; though it is among the least obviously concerned with the final frontier, it's one of the show's most popular.

"Artists," said the late Hereward Lester Cooke, "should be the key witnesses to history in the making." Cooke was the National Gallery's painting curator and an adviser to NASA's self-promotional art program. "In the long run, the truth seen by the artist is more meaningful than any other type of record."

Yet few turn to gallery painters for the "truth" about space. To see space-related art that has had any cultural impact, one must turn to commercial works: pulp art, paperback covers (many of them abstract), Hollywood posters. An essential difference is that commercial artists are emphatically not mere "witnesses."

They either engage you or have failed. In inviting you to detect a story, Casselli has managed to place an old form at the service of a contemporary subject. In so doing, he too has chosen to be something other than a witness.