This is exciting, because it opens the door for space elevators that don't rendezvous with a stationary point on the ground, but with hypersonic planes.<p><a href="http://en.wikipedia.org/wiki/Non-rocket_spacelaunch#Hypersonic_bolus_.28HASTOL.29" rel="nofollow">http://en.wikipedia.org/wiki/Non-rocket_spacelaunch#Hyperson...</a><p><a href="http://www.enotes.com/topic/Tether_propulsion#HASTOL_.E2.80.94_Earth_launch_assist_rotovator" rel="nofollow">http://www.enotes.com/topic/Tether_propulsion#HASTOL_.E2.80....</a><p>This puts the tensile strength necessary into the realm of existing high-strength polymer cables.<p>If we could build a robust fully-reusable space plane that can go Mach 15, and we could also find a way to rendezvous it with a rotating tether, we could free ourselves from the nastiness of the rocket equation and achieve inexpensive space access.
The most significant difference between this prototype and existing ICBM technology is that the reentry vehicle has more lift and less drag.<p>It's counterintuitive, but re-entry vehicles are typically bluntly shaped because it reduces the heat load on the nose cone by pushing the bow shock further out in front of the craft. The downside of this is higher drag and less lift, so ICBM warheads fall more than they glide.
>The HTV-2 is part of an advanced weapons program called Conventional Prompt Global Strike, which is working to develop systems to reach an enemy target anywhere in the world within one hour.<p>Wait, but don't ICBMs have like 40 min strike time for any target in the world since, like, sixties? (Ok, in the sixties they couldn't aim this fast).
I know they're very different beasts and in completely different situations, but it's still interesting to remember that Voyager 1, using 30+ yo technology, is currently going about three times as fast as this plane.
Some months ago I observed an object crossing the sky at night from Coventry UK. It crossed the entire extent of the sky in about 2 seconds. It was very high up and had a red glow like that of a jet afterburner. It didn't fade out or change brightness as you might expect of a meteor and wasn't white as you'd expect of a satellite. I wondered at the time if someone was testing a very fast military vehicle. It would be interesting to know what various nations are working on.
does anyone know if they had telemetry to the thing (which is difficult because of the plasma, but used to be possible at least at shuttle speeds from the tail)? or are they hoping some kind of black box survived? and if they had no telemetry is this report inferred from observations of the flight (only)?<p>[related - does the telemetry problem mean that if something like this ever went into production, it would be largely autonomous?]
Keep in mind that this vehicle was just for collecting data, a conventional rocket did the work to accelerate it to mach 20. There's nothing the HTV-2 can do other than decelerate and maneuver.