There seems to be a lot of buzz around the Internet that the now famous Roadster is going to overshoot mars. Was this intentional, just to show the kind of capacity it is capable of? Or was there some sort of miscalculation that caused them to burn for too long, or could there be other reasons for the overshoot?

  • $\begingroup$ There may indeed be other reasons. See for example Max Fagin's video after 02:00 which mentions a possible use of a perturbation from a near approach to Mars to prevent future intercepts with Earth's orbit. Also here. $\endgroup$
    – uhoh
    Commented Feb 8, 2018 at 21:55
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    $\begingroup$ A fair point - the obvious followup to "was it intentional" is "why" I suppose! $\endgroup$
    – corsiKa
    Commented Feb 8, 2018 at 21:57
  • $\begingroup$ It's a good question. It's better not to pre-guess the answer within the question. Leading questions like "Is it A or B?" can backfire if it's actually "C". $\endgroup$
    – uhoh
    Commented Feb 8, 2018 at 21:59
  • $\begingroup$ Possible duplicate of Was SpaceX's venture into the asteroid belt a "convenient accident" on purpose? $\endgroup$ Commented Feb 9, 2018 at 2:31
  • $\begingroup$ @ReactingToAngularVues there is a much better answer here than there is there. In fact I believe the answer there is problematic (I've left a comment). I think in this case the close vote is not helpful. $\endgroup$
    – uhoh
    Commented Feb 9, 2018 at 3:51

1 Answer 1


It was entirely intentional to enter a solar orbit with an aphelion past Mars' orbit. There was never any intent to target Mars itself, since this is simply the wrong time in the synodic period to attempt that. It did not "overshoot Mars" since Mars isn't in the crosshairs here. The only objective was to show that the vehicle could deliver enough energy to the payload so that you could target Mars if you wanted to, in a proper opportunity.

The only miscalculation was in an image that Elon Musk tweeted that showed about the correct $C_3$, but also showed a miscalculated and way too large resulting aphelion. The correct aphelion is closer to 1.7 AU.

  • $\begingroup$ So can I infer from this that these two observations are correct: first, that the spacecraft's is exactly (or rather, sufficiently close to) where it was intended to be and that 2) the media is abusing the fact that most people believe, for whatever reason, that it was headed to Mars and are just trying to get clicks by making it look like Musk pulled a Tim the Tool Man Taylor with the rocket? $\endgroup$
    – corsiKa
    Commented Feb 8, 2018 at 22:34
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    $\begingroup$ Yes, it is sufficiently close to what they intended and expected. I don't know what pulling a Tim the Tool Man Taylor is, so I can't answer to the second part of your question. $\endgroup$
    – Mark Adler
    Commented Feb 8, 2018 at 22:53
  • $\begingroup$ More about aphelion here. Thanks @MarkAdler for initially flagging this in Space SE by the way! $\endgroup$
    – uhoh
    Commented Feb 8, 2018 at 22:55
  • $\begingroup$ @MarkAdler: I think corsiKa was referring to something like this. $\endgroup$ Commented Feb 9, 2018 at 1:15
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    $\begingroup$ so, once it reaches Mar's orbit will it need to call a tow truck? $\endgroup$
    – jean
    Commented Feb 9, 2018 at 19:29

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