As of late-December 1997, the Mars Global Surveyor spacecraft has been in orbit for somewhat over three months. During that time, the orbital period was reduced from about 45 hours to about 26 hours. Owing to problems with the spacecraft's solar panel, aerobraking will take longer than originally planned, and the spacecraft will not achieve the mapping orbit (sun-synchronous, 400 km circular polar orbit) until March 1999 (the original date was March 1998). The plan is to slowly aerobrake to an orbit with an intermediate period (just under 12 hours), rise up out of the atmosphere in the Spring 1998 and observe the planet from that orbit for several months, and then resume aerobraking in the Fall.
The Mars Orbiter Camera has been imaging the planet during a roughly 10-15 minute period shortly after passing through the atmosphere, as the spacecraft rotates from the aerobraking attitude (with the camera pointed in the opposite direction of travel and parallel to the surface) to the spinning, sun-and-earth-facing attitude it maintains during the rest of the orbit. The limiting factor for the amount of images that can be taken is the size of the camera's internal digital memory or buffer(about 80 Mbits). One "buffer load" is acquired each orbit. Errors in commanding, ground data system losses, unplanned spacecraft events, and other factors have led to about 20% loss of data (the MGS Project has a requirement of meeting 70% data return during the mapping mission, but has no requirement on returning data during aerobraking). The bits are divided between low resolution wide angle (WA) camera and high resolution narrow angle (NA) camera images on an orbit-by-orbit/image-by-image basis, based on what parts of the planet are to be overflown, the state of the atmosphere (whether or not there are clouds, hazes, or dust, etc). Early in the mission, wide angle images were very poor owing to the bad illumination conditions, and only a few, small WA images were acquired. During the recent dust storm, when surface definition was very poor, NA images showed very little, but the WA images showed details of the dust clouds, so more of the bits were allocated to WA imaging.
Click on images or the name below each image to proceed to that release.
Schiaparelli Crater Rim and Interior Deposits (Orbit 23, Images 2 and 3)
Medusae Fossae Formation (Orbit 31, Image 4)
Flow-ejecta Crater in Icaria Planum (Orbit 45, Image 5)
A Regional
View on Orbit 63 (Orbit 63, Images 1 and 2)
Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
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