According to telemetry as seen in videos of the event, the car was ejected from the Stage 2 rocket at 114km above Earth.

  • Anything less than 160km will immediately enter a rapidly decaying orbit and will descend to Earth.
  • The car had no independent boosters or guidance system on it.

  • The car's whole-Earth, blue-marble photo must have been taken at least 800km from Earth (the exact distance is hard to find on the internet, as opinion on 'space forums' and the like is hugely varied - some say 1600kms, some say you can 'never' see a whole-Earth image due to non-converging tangents or something (?)).

Either way, only 2 other whole-Earth photos exist (apparently) one on Apollo 16 (with 35mm film) and the second recently by DSCOVR (at 1.5 million km away with a 1024x1024 pixels)

How did the car get from 114km to a distance necessary to get the whole-Earth image without rocket-boosters and guidance?

  • 2
    What makes you think it wasn't on a booster? – user1666620 Feb 12 at 17:31
  • Can you confirm it was? I'm hoping for clarification. – MGC Feb 12 at 17:35
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    Why do you think it was "ejected" from the second stage? And specifically at that height? – jkavalik Feb 12 at 17:39
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    Discussion of whole-Earth images: space.stackexchange.com/questions/6161/… – Hobbes Feb 12 at 18:00
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    You're mixing up the fairing ejection (which happens as soon as the atmosphere is thin enough as nobody wants to haul the weight to orbit) with ejecting the car--which didn't happen. – Loren Pechtel Feb 13 at 6:02

The orbit during the 5.5 hour coast period of time extended to about 7000 km above the Earth. They didn't actually photograph a whole Earth effect. Take this image from Elon's feed, above Australia. Note that Australia takes up a large part of the image, it isn't really a whole Earth effect.

enter image description here

The final shot possible would have taken place 6 hours after the last burn, at which time the battery was supposed to run out. The last picture shown was this one. There is no word about the time this occurred. The 12 hour mark puts the car at about 110,000 km, which is high enough where a near whole Earth view would be possible.

enter image description here

  • Thank you for your reply. To explain my original question, I had previous been under the impression (because official SpaceX animations appear to show it) that the car was floating free off any rocket, from the 114km ejection-point onward. It appears from what you are saying, that the photo you have included shows the car still attached to a portion of rocket...cbsnews2.cbsistatic.com/hub/i/2018/02/06/… – MGC Feb 12 at 18:32
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    It isn't actually clear if the car is free floating, but if it is, it happened after the 3rd burn. I don't think the Roadster could transmit an image on it's own, it would need the booster stage to transmit that image. – PearsonArtPhoto Feb 12 at 18:36
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    Afaik it was confirmed by engineers that no separation happened. And then it seems verified by the available recordings from telescopes. – jkavalik Feb 12 at 19:03

At 114 km altitude, the fairing was ejected. This is in the middle of the first burn for stage 2. The car is firmly attached to the stage at this point, and it remains attached throughout the flight. A payload separation would have shown up in the webcast, and separation is impossible while the second stage engine is running.

  • +1 for the important information that only the fairing was separated at 114 km altitude and the car was never separated. – Uwe Feb 12 at 18:12
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    Strictly speaking, separation is possible while the engine is running. The problem is that you will end up with lots more separations that you expected. :-) – Diego Sánchez Feb 12 at 20:42
  • Separation while the engine is running can be done with a big enough rocket motor (to accelerate the payload faster than the almost-empty stage), but with no rocket motor in the payload, we can discount that option. – Hobbes Feb 12 at 20:45
  • @DiegoSánchez Tell that to the hot-starting Russian rockets! – 0xDBFB7 Feb 12 at 21:27

You can seen in the official launch video at 28:53 that:

  • the final stage is still firing (see red glow in top right image)
  • the payload is at 169 km and climbing (see top right dials)

So, the premise that the car was ejected at 116 km is false.

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