100km is the Kármán line, the generally accepted boundary of space. It&#x27;s the point at which aeronautics become useless, as the atmosphere is too thin to support lift greater than your weight without going faster than orbital velocity. Contrary to popular belief, in Low Earth Orbit you&#x27;re still very much in reach of the Earth&#x27;s gravity; it&#x27;s only about 10% less than the gravity on the surface.[2] The tricky part about orbit is moving <i>sideways</i> fast enough that you miss the ground.<p>So Blue Origin indeed got to space, landed and did it again. But it took a tiny fraction of the energy of the same feat for an orbital rocket (which is why SpaceX can only land its first stage).<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;K%C3%A1rm%C3%A1n_line" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;K%C3%A1rm%C3%A1n_line</a><p>[2] <a href="https:&#x2F;&#x2F;what-if.xkcd.com&#x2F;58&#x2F;" rel="nofollow">https:&#x2F;&#x2F;what-if.xkcd.com&#x2F;58&#x2F;</a>