Inspired by How to calculate degrees above/below horizon? (For KiNET-X rocket getting to an altitude of over 200 miles.) and this NASA article/blog post, specifically this paragraph:

The vapor will be released approximately 9 minutes and 30 seconds to around 10 minutes after launch at about 217-249 miles altitude over the Atlantic Ocean and 540-560 miles downrange from Wallops and just north of Bermuda.[emphasis mine]

And this image showing ascent visibility:

KiNET-X launch visibility click for larger

I pixel mapped the centers of the different circles (they are not concentric!) and thus inferred a ground track of the vehicle:

Ground track points click for larger

The red points are the centre of each circle, progressing out over the ocean as expected, except they decidedly do not point towards "just north of Bermuda":

heading constraints click for larger

The upper line is the heading using only the first two inferred ground track points and points towards "just north of Bermuda". Here are the 540 & 560 mile range markers for extra reference:

540 & 560 mile markers with headings click for larger

What is causing this discrepancy? Could it be a projection mis-match from my flat, pixel-mapped circles to the rounded map (Google Earth) used in the ascent visibility visualization (first picture)?

  • 1
    $\begingroup$ Is there a way to make images not as large in posts? $\endgroup$ May 15 at 20:41
  • 1
    $\begingroup$ yep there is :-) $\endgroup$
    – uhoh
    May 15 at 21:10
  • 1
    $\begingroup$ Love it! Are the red centers that you made of each circle in order, from inside to out? I wonder if someone just used Photoshop to make the circles, and didn't zoom in to click the same point to draw each circle. If the centers are in order, it might make this less likely. $\endgroup$ May 16 at 5:35
  • $\begingroup$ @user1902689 yes they are in order from inside (the one on the land mass) to out (the one furthest away over the ocean), that's quite possible too $\endgroup$ May 16 at 11:38

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.