January 16, 2004
With barely a week before reaching Mars, NASA's Opportunity spacecraft adjusted its trajectory, or flight path, today for the first time in four months.
The spacecraft carries a twin to the Spirit rover, which is now exploring Mars' Gusev Crater. It will land halfway around Mars, in a region called Meridiani Planum, on Jan. 25 (Universal Time and EST; Jan. 24 at 9:05 p.m., PST).
For today's trajectory correction maneuver, engineers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., commanded Opportunity at 6 p.m. PST to fire thrusters in a sequence carefully calculated by the mission's navigators. The spacecraft is spinning at two rotations per minute. The maneuver began with a 20-second burn in the direction of the axis of rotation, then included two 5-second pulses perpendicular to that axis.
"Looks like we got a nice burn out of Opportunity," said JPL's Jim Erickson, mission manager. "We're on target for our date on the plains of Meridiani next Saturday with a healthy spacecraft."
Before the thruster firings, Opportunity was headed for a landing about 384 miles west and south of the intended landing site, said JPL's Christopher Potts, deputy navigation team chief for the Mars Exploration Rover Project. The maneuver was designed to put it on course for the target.
Opportunity's schedule still includes two more possible trajectory correction maneuvers, on Jan. 22 and Jan. 24, but the maneuvers will only be commanded if needed.
As of 5 a.m. Sunday, PST, Opportunity will have traveled 444 million kilometers (276 million miles) since its July 7 launch, and will have 12.5 million kilometers (7.8 million miles) left to go.
JPL, a division of the California Institute of Technology, manages the Mars Exploration Rover project for NASA's Office of Space Science, Washington, D.C. Additional information about the project is available from JPL at http://marsrovers.jpl.nasa.gov and from Cornell University, Ithaca, N.Y., at http://athena.cornell.edu .
Guy Webster (818) 354-5011
Donald Savage (202) 358-1547
NASA Headquarters, Washington, D.C.