The NEAR Shoemaker spacecraft--the first to orbit an asteroid--embarks on a series of low-altitude passes over 433 Eros this month in a prelude to its daring February descent to the surface of the rotating, 21-mile-long space rock.

The orbit segment of NASA's Near Earth Asteroid Rendezvous mission wraps up Feb. 12 with NEAR Shoemaker's controlled descent to Eros, a tricky maneuver that will allow the craft's digital camera to snap close-ups of the asteroid's cratered, boulder-strewn landscape. But the weeks before the historic event won't be much easier, as NEAR mission operators and navigators take the spacecraft on several low passes over the ends of the potato-shaped Eros from Jan. 24 to 28.

"NEAR Shoemaker is nearly out of fuel, and by the end of January it will have completed its scientific objectives at Eros," says Robert W. Farquhar, NEAR mission director at APL. "The maneuvers are kind of risky, but we want to end the mission getting a lot of bonus science--with images better than we've ever taken."

On Jan. 24, NEAR Shoemaker will dip from its current 22-mile circular orbit to begin a four-day series of flyovers. The spacecraft will complete five to six passes, each within about three to four miles of the surface. In the early hours of Jan. 28 the spacecraft will zip between one to two miles over the surface--closer than it has ever come before.