(Translated by https://www.hiragana.jp/)
MGS Mars Relay---MSSS/MOC Role
The Wayback Machine - https://web.archive.org/web/20140811124051/http://www.msss.com/mars_images/mars_relay/




The First Interplanetary Internet Service Provider:
Data from Deep Space 2 and Mars Polar Lander
via the Mars Global Surveyor Mars Relay and Mars Orbiter Camera


January 3, 2000: The Mars Relay has been used repeatedly since December 3, 1999, in attempts to communicate with the Deep Space 2 probes and Mars Polar Lander. The Mars Relay sends its data through the camera (MOC) onboard the Mars Global Surveyor (MGS). Each attempt to listen for the lander uses some fraction of MOC's computer space that might otherwise be used for new pictures of the martian surface. Attempts to hear from Mars Polar Lander are continuing into January 2000.

January 19, 2000: Attempts to communicate with Mars Polar Lander via the Mars Relay and Mars Orbiter Camera onboard Mars Global Surveyor were concluded on January 17, 2000, with no successful contact. NASA/JPL declared the end of the Mars Polar Lander mission on that date. The Mars Relay is not anticipated to be used again until some future date when there is a new Mars lander on the surface of the red planet.

January 29, 2000: The Mars Relay was turned on once again this past week as part of renewed efforts to recover a signal from the Mars Polar Lander. The Mars Global Surveyor Mars Orbiter Camera relays data about the health of the Mars Relay during this search period. A Jet Propulsion Laboratory release dated January 25, 2000, explains.... CLICK HERE.

March 22, 2000: The Mars Relay was once again turned off in early March after unsuccessful attempts to "hear" the Mars Polar lander in January and February 2000. At this time, the Mars Relay is not expected to be used again until such time when a new lander arrives at Mars--an event not expected until 2003 or 2004 at the earliest.


From Mars to Earth

Data from the surface of Mars are sent by radio using either a direct-to-Earth link from an antenna on the lander, or through the Mars Relay antenna on the orbiting Mars Global Surveyor spacecraft. Read More...


Role of MGS MOC and Malin Space Science Systems

Malin Space Science Systems (MSSS) plays a unique role in the Mars Relay process. Data received by the Mars Relay antenna on Mars Global Surveyor (MGS) are stored in the Mars Orbiter Camera (MOC) buffer and returned to Earth with the MOC images. MSSS decompresses the raw data and transfers them to the Mars lander teams. Read More...


Relay from Deep Space 2 (Amundsen and Scott) and Mars Polar Lander

The Mars Relay is the only link by which data are returned from the two Deep Space 2 Mars Microprobes, Amundsen and Scott. These probes do not have direct-to-Earth capability. The Mars Relay on MGS can also be used by the Mars Polar Lander--a role that has become more likely following the September 1999 loss of the Mars Climate Orbiter. Read More...


International Origins and the History of Mars Relay

In the late 1980's, international cooperation in Mars exploration led to development of the Mars Relay antenna by the French space agency. The purpose was to relay data from 2 balloons that would be sent to the red planet onboard the USSR Mars '92 mission. The relay antenna was placed aboard the US Mars Observer spacecraft for this purpose. Today the Mars Relay is aboard Mars Global Surveyor and is expected to support the Deep Space 2, Mars Polar Lander, and Mars Surveyor 2001 Lander missions. Read More...


Mars Relay Technical Details

A lander on the surface radios its data to the Mars Global Surveyor as it passes overhead. The data are transfered to the Mars Orbiter Camera (MOC) for storage and relay back to Earth. Relayed data are received at Malin Space Science Systems, decompressed, and provided to the lander teams. Read More...


Image Credits, this page--- Artwork modified from NASA/JPL/Caltech Mars Polar lander, Mars Global Surveyor, and Deep Space 2 artwork; Photos modified from NASA/JSC, NASA/JPL/LMA, and NASA/JPL/MSSS photos.




© 2000 Malin Space Science Systems, Inc.