<i>By contrast, the Blue Origin rocket went straight up, and straight back down...From a space applications perspective it is not much more useful than a blimp.</i><p>Actually, the &quot;pop-up&quot; 1st stage trajectory is interesting from a space applications perspective. You can think of it this way: a SSTO spaceplane is just beyond the cusp of possible for technology made out of normal matter and fueled by chemical rockets. But what if you could somehow cheat and launch an SSTO at very high altitude? Then it&#x27;s just below the cusp of possible. So you wind up with a completely reusable TSTO craft.<p>So how is that more interesting than a high altitude blimp? You get the craft back faster, directly to the facility. Recovery is more straightforward. The equipment and technology is the same sort of equipment and technology as in the orbiter craft. Also, if you&#x27;re able to get up to a &quot;mere&quot; 600 mph or so downrange velocity, due to the mathematics of the rocket equation, you&#x27;re still saving a sizable chunk of vehicle weight in fuel.