In the film, Gravity, the protagonists are warned early on of destruction headed their way.

The debris from a Russian missile strike on one of their defunct satellites is headed right towards them, coming in at high-speeds, and even killing almost the entire crew on their mission.

My question is: shouldn't NASA have predicted this beforehand? I'm not a rocket scientist, but wouldn't they have been aware of the missile and subsequent debris more than a minute before it affecting such an expensive mission? Would this ever really happen? And would it play out like it did in the film?


1 Answer 1


First of all, the NASA noticed the destruction of the Russian satellite early on and even informs the crew about it, though just saying that it won't impede their operation. What they didn't anticipate was the resulting chain reaction with debris creating more debris and so on. This was indeed only noticed by the NASA when it was already too late (yet still only some 3 minutes after the satellite had been destroyed) and the debris was very near heading for the shuttle. It wasn't only the debris of the satellite directly that headed their way (and that ultimately destroyed nearly all the stuff in earth's orbit), but the additional debris created by the debris of the debris of the..., which is the reason why NASA at first didn't regard that one destroyed satellite far away as an immediate danger for the mission.

This kind of chain reaction catastrophe is indeed a real hypothesized scenario, called the Kessler syndrome. Yet I have no idea if it would happen exactly that way in reality, since the movie, while seeming pretty realistic to a layman, took some artistic freedom in many details. To get some insights into the particular scientific (in)acccuracies of the movie in certain parts, you can take a look at this interview (just don't take it too serious and don't let it ruin the movie for you, it's still just a fictional movie and not a documentary). It also gives some comment on the space debris:

What's your experience with space debris? If you're out on a space walk, what are you seeing around you?

Well, first of all, if you see it, it's too late. That was quite implausible, to me, first off, the chain of events that would take down the world's telecommunications. Things don't quite move in that pattern. But that notwithstanding, if there were a cloud of Micro-Meteoroid Orbital Debris, what we call MMOD, it would be coming at tens of thousands of miles an hour. I don't know if you've ever looked at a bullet coming straight at you. Hopefully not, but if you had, you wouldn't appreciate it for very long. And these would be a much tinier, swarmlike pattern of debris coming at perhaps twenty times the speed of sound. And you wouldn't see it at all; it would just rip through everything in its path. So it's kind of a spacewalker's doomsday scenario.

So given that the movie wasn't entirely accurate in the way a hypothetical Kessler syndrome would pan out in reality, I think there isn't a sure way to say if NASA could have reacted a few minutes earlier or not.

Yet in the context of the movie and given that nobody really took this worst case scenario into account, it isn't too unreasonable that NASA didn't take the destruction of a Russian satellite (which might not have happened for the first time) too serious before it was already too late (and also no way to say if the shuttle crew could have made it had they aborted at the moment the satellite was destroyed).

  • "Yet I have no idea if it would happen exactly that way in reality" - See China's explosion of a satellite in 2007. Greatly increased the amount of space junk up there, but didn't cause a cascade like in the film.
    – user209
    Commented Oct 14, 2013 at 16:05
  • @Keen Yeah, that's indeed the reason why NASA probably didn't take that satellite destruction serious either. Kessler syndrome doesn't seem too likely, yet I guess it could happen, but as said have no idea if it would work as depicted if it would happen (though, probably not exactly as depicted at all).
    – Napoleon Wilson
    Commented Oct 14, 2013 at 16:16
  • Micrometeoroids are different from the type of space debris produced by a fragmenting satellite. As the name suggests, they are micro in size (about 0.001 - 1 mm). The debris from satellites will be a range of sizes from sub-millimetre up to metres. So you would never see tiny debris coming towards you but it should be possible to see a truck-sized satellite 1 or 2 seconds in advance (moving at around 1-10 km/s relative to you) if it's in sunlight. In the film they seem to have exaggerated the visibility of the debris giving around 10 seconds warning.
    – binaryfunt
    Commented Mar 12, 2019 at 16:50

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