National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
News & Events
Spirit Mission Status
Spirit Mission Status
20 Nov 2003
(Source: Jet Propulsion Laboratory)

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov

Guy Webster (818) 354-6278
Jet Propulsion Laboratory, Pasadena, Calif.

NEWS RELEASE: 2003-153
November 19, 2003
Mars Exploration Rover Mission Status

NASA's Spirit spacecraft made its third trajectory correction maneuver on Friday, Nov. 14, fine tuning its flight path toward Mars with an engine-firing operation planned into the seven-month trip.

The trajectory adjustment was designed to alter Spirit's velocity by 0.6 meters per second (1.3 miles per hour), moving the arrival point by 770 kilometers (478 miles) and arrival time by 16.5 minutes closer to the planned target location and time, said Louis D'Amario, the project's navigation team chief. To accomplish that adjustment, the flight team commanded Spirit to fire its engines for 132 seconds in the direction of the spacecraft's rotation axis and for short pulses totaling 27 seconds in a direction roughly perpendicular to the rotation axis.

Spirit has three more scheduled dates for additional trajectory corrections before reaching Mars less than seven weeks from now. The spacecraft is carrying the first of two Mars Exploration Rovers equipped to examine the geology around their landing sites for evidence about past environmental conditions.

Both Spirit and its twin, Opportunity, have rebooted their computers in the past two weeks. Mission controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., sent commands for that procedure on each spacecraft to correct possible corruption of computer memory registers by radiation from powerful solar flares in late October and early November. The flares were among the most intense ever recorded.

"We had no evidence of memory problems, but we considered it prudent to reboot both spacecraft to assure memory integrity, using the sleep-wake cycle that we plan to do each night after the rovers are on the surface of Mars," said JPL's Peter Theisinger, project manager for the Mars Exploration Rover Project.

High-energy protons ejected by the stormy Sun appeared on Oct. 28 as bursts of bright spots in star-tracking instruments used by both Spirit and Opportunity to sense the spacecrafts' orientation. The instruments interpreted the proton hits as stars, so the bursts overwhelmed their ability to recognize star patterns and determine spacecraft attitude. Both spacecraft temporarily switched to a backup method of attitude sensing, using the Sun. They resumed use of the star trackers last week.

Spirit's target is arrival at Mars' Gusev Crater at 04:35 Jan. 4, 2004, Universal Time (8:35 p.m. Jan. 3, Pacific Standard Time and 11:35 p.m. Jan. 3, Eastern Standard Time). These are "Earth received times," meaning they reflect the delay necessary for a speed-of-light signal from Mars to reach Earth; on Mars, the landing will have happened nearly 10 minutes earlier. Three weeks later, at 05:05 Jan. 25, Universal Time, Opportunity will arrive at a level plain called Meridiani Planum on the opposite side of Mars from Gusev. Each rover will examine its landing area for geological evidence about the history of water there, key information for assessing whether the site ever could have been hospitable to life.

As of 6 a.m. PST on Nov. 19, Spirit had traveled 396.5 million kilometers (246.4 million miles) since its June 10 launch, with 91.5 million kilometers (56.2 million miles) to go before reaching Mars. Opportunity, launched on July 7, had traveled 326 million kilometers (202 million miles) and has 130 million kilometers (81 million miles) yet 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://mars.jpl.nasa.gov/mer and from Cornell University, Ithaca, N.Y., at http://athena.cornell.edu/ .

News Archive Search  Go!
Show  results per page
 
 
Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writer: Autumn Burdick
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> USA.gov
> ExpectMore.gov
> NASA Advisory Council
> Open Government at NASA
Last Updated: 20 Nov 2003