SpaceX recently announced their plans for creating a 1-hour flight service using BFR rockets which would fly higher than commercial airliners but lower than ISS. It implies that within 1 hour it would be able to reach any point on the globe (with a suitable launchpad).

I'm curious and a bit worried about the potential of intersecting trajectories with airliners and satellites on lower orbits. There are also plans from SpaceX to launch around 12 thousand satellites starting in 2020 to serve internet connection. All of this makes me wonder what the chances are of colliding with so many flying objects.

There's the famous XKCD illustration for "going to space", and to me it seems like BFR is going to fly in a similar manner. What are the actual trajectories going to look like? How will they compare to airline trajectories?

Also, I'd like to see a visual representation of intersecting airspaces of airliners, existing satellites and the planned internet satellites, to get a general idea of it all.

  • $\begingroup$ Airlines do not have a "trajectory", they have a flight path at a consistent altitude. $\endgroup$
    – GdD
    Oct 2, 2017 at 10:04
  • $\begingroup$ @GdD feel free to correct my terminology and tags $\endgroup$ Oct 2, 2017 at 13:04

1 Answer 1


Satellites in LEO are between 100-1240 miles, and the BFR is certainly intending to reach LEO to deliver satellites. For global transport, the BFR would enter this region - but that doesn't make a huge chance of colliding with "so many objects" as space is still really empty.

In terms of collision risk with aeroplanes - no, this really isn't an issue. Airspace is also very empty except around major airports, and the location of aircraft is well known. A rocket will only be at the same altitude as aircraft (up to 40000ft or so) for a very short period of time, and while planes fly horizontally, a ballistic trajectory is almost vertical at the same altitude.

So you shouldn't be worried about this as an issue at all.

(There are many other reasons why this is unlikely to work, unfortunately)

  • 2
    $\begingroup$ I'd like to learn more about those other reasons $\endgroup$ Oct 2, 2017 at 13:05
  • 2
    $\begingroup$ @user1306322 - many articles out on to. this has some thoughts: theverge.com/2017/9/29/16385026/… $\endgroup$
    – Rory Alsop
    Oct 2, 2017 at 14:04
  • 2
    $\begingroup$ That article has some good points but some other really bad ones. Radiation exposure might be smaller due to shorter trip than airlines. Pilots ... are definitely out of the loop on rockets anyway. $\endgroup$
    – Antzi
    Oct 2, 2017 at 15:43
  • $\begingroup$ agreed - it was just a quick google from my phone. Loads of info out there though. $\endgroup$
    – Rory Alsop
    Oct 2, 2017 at 16:47

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.