The Sojourner rover was deployed as part of the Mars Pathfinder mission. At the end of the mission, the Sojourner rover was still operable. But the base station that the Mars Pathfinder carried failed. So communication with the rover was lost. Presumably the base station is completely inoperable after this failure.

I can't find any specifications on the frequency used to communicate from the base station to the rover. But the rover has a prominent dipole antenna sticking out of it. This is presumably it's only radio antenna. Is the rover just sitting there waiting for its next set of commands? If I had the correct antenna and transmitter in orbit around Mars, could I start using the Sojourner rover again?


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If it were still working and you have a powerful enough transmitter and sensitive enough receiver on your orbiter (likely requiring a high-gain antenna), then I suppose. However there is no way that it's still working.

The modem on the Sojourner rover is designed to communicate with a companion modem on the Mars Pathfinder lander no more than a few meters away. It would take some effort to design something to communicate with Sojourner from orbit, but with sufficient determination, it could probably be done.

The Sojourner rover primary batteries are dead. The solar cells are covered in dust. The rover has gone through many deep thermal cycles over several Martian years, with the mechanical thermal mismatches very likely breaking electrical connections, rendering the rover unrecoverable. It is most sincerely dead.

When Sojourner continued to operate after the lander died, it did not sit still. It was programmed to drive around in case it somehow got out of range of modem communication, hoping that the driving would bring it back in range. We have evidence from orbital images that in fact Sojourner is not currently where we last saw it with the lander camera. It drove, maybe several times, before it finally succumbed to the Martian environment.

  • 3
    $\begingroup$ I hope someone asks a follow-up question about those orbital images. $\endgroup$
    – uhoh
    Jan 25, 2017 at 2:45
  • 3
    $\begingroup$ You can google it. The images are easy to find. $\endgroup$
    – Mark Adler
    Jan 25, 2017 at 5:35

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