Spaceflight Now: Breaking News

Rescheduled rendezvous burn to keep NEAR on course
Posted: Feb. 3, 2000

Mission operators were set to send commands to NEAR Wednesday night for a revised engine burn that will keep the spacecraft on course for asteroid Eros.

Set for noon EST (1700 GMT) today, the burn will cut NEAR's approach speed from 45 mph to 21 mph (relative to Eros) and refine its trajectory toward the giant space rock.

A rendezvous burn scheduled for Wednesday was canceled when NEAR went into a "safe" hold early in the morning, soon after turning on its accelerometers for the maneuver. During safe mode, NEAR's onboard computers halt operations and await instructions from Earth.

The NEAR team continues to study the anomaly, but to avoid a similar occurrence today, the team has decided to leave the accelerometers on until after orbit insertion on February 14.

Near sees Eros' saddle. Photo: JHU/APL
On February 1, the multispectral imager on the NEAR spacecraft acquired this image of the asteroid 433 Eros. When the image was acquired, NEAR was approximately 7,800 miles (11,600 km) from the asteroid. The image is part of a series taken during calibration tests being conducted during in the last stages of approach to the asteroid.

At this resolution of 0.7 miles (1.2 km) per pixel, a "saddle" is apparent at the upper left of the asteroid, near the terminator separating the day and night sides. This saddle, discovered in NEAR flyby images taken in December 1998, is the location of unusual bright rock deposits that scientists are eagerly waiting to see in high resolution images from Eros orbit later this month.

On February 14 NEAR will fire its thrusters and begin to orbit Eros, becoming the first artificial satellite of any asteroid. NEAR is designed to return science data to answer fundamental questions about the origin and composition of asteroids, comets and our solar system.

Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions.

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