| 12 August 1999
For Immediate Release
NEAR Engine Burn Puts Spacecraft on Target for EROS
At 1 p.m., today, a 2-minute hydrazine engine burn put the NASA Discovery Program's NEAR spacecraft, on a direct path to intercept asteroid 433 Eros early next year. Commands from the Near Earth Asteroid Rendezvous Mission Operations Center at The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., were carried out flawlessly by the spacecraft.
"The burn was a good test of the orbit correction process we will be using when we reach Eros," says Mark E. Holdridge, NEAR Mission Operations Manager. "We'll be using the same flight software and systems to put us into orbit around the asteroid so we're really pleased to see how well they worked." The burn was the last scheduled major trajectory correction of the mission. It slowed the spacecraft's velocity by 47 mph (21 meters per second) relative to the sun, or slightly more than half the change needed to put NEAR in the correct position and speed to rendezvous with Eros on Feb. 14. The final velocity changes will be implemented in early February 2000.
Robert W. Farquhar, NEAR Mission Manager says, "We had to complete this burn in order to reach Eros on February 14, 2000. Without it we would have missed the asteroid by about 106,000 miles."
The craft is now approximately 335,000 miles (539,000 kilometers) from Eros. If any additional trajectory correction is needed it will take place on Oct. 20. "The spacecraft and instruments are all operating well," Farquhar says. "We see smooth sailing from now until we reach Eros on Valentine's Day."
The spacecraft is now operating, and will remain operating, on its main computer (Flight Computer 1). All of NEAR's instruments are turned on and for the next few months the mission operations team will be calibrating instruments and testing systems in preparation for rendezvous and the yearlong study of the asteroid.
NEAR will carry out the first comprehensive study of a near-Earth asteroid. After rendezvousing with asteroid Eros on Feb. 14, 2000, it will spend the next year orbiting the asteroid to determine its physical geology, composition, and geophysics.
For more information on the NEAR mission, visit Web site: http://near.jhuapl.edu
The Applied Physics Laboratory is a not-for-profit laboratory and independent division of The Johns Hopkins University. APL conducts research and development primarily for national security and for nondefense projects of national and global significance. APL is located midway between Baltimore and Washington, D.C. in Laurel, Md.