During descent phase and entering Mars' atmosphere, was the rover's descent controlled by the Earth based ground station, or by the rover itself?

What are the technical challenges, when communicating with an Earth based ground station during descent phase entering Martian atmosphere?

  • $\begingroup$ There's a video "Seven minutes" or something like that at JPL's site. Precisely about EDL (Entry, Descent and Landing). You can't control anything that fast with the comms lag between us and Mars, so the MSL had to go on her own. $\endgroup$ Aug 18, 2013 at 14:23
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    $\begingroup$ youtube.com/watch?v=Ki_Af_o9Q9s (Challenges of Getting to Mars: Curiosity's Seven Minutes of Terror) $\endgroup$
    – s-m-e
    Aug 18, 2013 at 14:38
  • $\begingroup$ Did it communicate with Earth? Yes. Was it controlled from Earth? No. $\endgroup$ Aug 18, 2013 at 22:01
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    $\begingroup$ With communication roundtrip between 8 and 40 minutes (depending on Earth-Mars orbital orientation) control from Earth would be pointless - we wouldn't be able to react to changing conditions in any reasonable time anyway. $\endgroup$
    – SF.
    Aug 19, 2013 at 10:49

1 Answer 1


The Curiosity Rover's descent stage was entirely autonomous. As mentioned in some of the comments, "7 Minutes of Terror" is a video by the MSL Team which visualizes the descent stage [watch it at http://www.youtube.com/watch?v=Ki_Af_o9Q9s ]. The significant delay in one-way communication (from 3-21 minutes) is the main challenge, and means that much of what the rover does is autonomous. In fact, by the time that mission control received the signal from MSL indicating it had reached the upper part of the atmosphere, the rover had already landed on the surface of Mars.

For more on Communication Delay, check out: http://www.spaceacademy.net.au/spacelink/commdly.htm

  • $\begingroup$ jalaha, welcome to Space Exploration! The site you linked to isn't generally available, could you please summarize the main points in your post so as to prevent link rot? $\endgroup$ Aug 20, 2013 at 5:28
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    $\begingroup$ The landing was autonomous, yes, but I think the answer is more complex. Curiosity sent a rather constant stream of data during EDL, basically some so-called "heart beat signal" plus telemetry data of what was going on. So the really interesting question is, how did sending and receiving during EDL work? What about data relays? What about issues like radio blackout during atmospheric entry? $\endgroup$
    – s-m-e
    Aug 20, 2013 at 6:24
  • $\begingroup$ @ernestopheles This is a good point. I've added a link to your comment here. $\endgroup$
    – uhoh
    Oct 21, 2016 at 0:22

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