I designed this data visualisation largely because I was fed up of news agencies in 2016-17 reporting things like: "North Korea has launched an inter-continental ballistic missile. It reached an altitude of 4,500 km and flew a distance of 965 km, according to South Korea's military."
Now, if you're a layman, or even an engineer or physicist with not much knowledge of orbital mechanics or flight path geography, you probably have very little idea what those numbers mean - realistically speaking. You may be thinking:
"How high is that?"
"Could that fly far enough to reach [city/country]?"
"So did it go high enough to get into space, or what?"
Newspaper editors seem to have a habit of failing to qualify their reported numbers with basic relative comparisons, and it's even rarer to see a comprehensive diagram or visualisation presented to give readers an actual picture of why it's big news that a little East-Asian country is firing little rockets at distances you can't picture in your head unless you have facts memorised such as the radius and circumference of the Earth, the altitude at which the atmosphere stops and space starts, or how far up man-made satellites usually fly.
I had the idea to develop a diagram that showed, as simply as possible, the extent of these missile launch trajectories relative to the size and curvature of the Earth, its atmosphere and the immediate vicinity of low earth orbit, as well as distances and ranges relating to notable cities, nations and landmasses - all to scale.
I discovered that the Nuclear Threat Initiative has produced an excellent database and some great diagrams of their own to to document the ballistic missile launches and nuclear tests that North Korea has conducted since 1984. Link: http://nti.org/6928A
Using the data from the CNS North Korea Missile Test Database, I produced the above and below figures accounting for missile launch counts and trajectories, split up by projectile type.
(note: only successful launches are recorded, with the exception of satellite launch attempts.