Potential RRL Altitude Attempt (Split from Q&A)

I think the altitude record for a rocket plane is now held by SpaceShipOne flight 17P - 112km.

Just a quick estimate for the lowest possible altitude reachable.

Velocity Airframes for the XL are quoted as weighing 1700-1800 lbs, I believe the IC propulsion unit weighs ~460 lbs or so, but we can neglect that and assume that some of this weight difference is compensated by the rocket engine(being made for sustained use, it's probably got a low T/W ratio, much lower than 100) and tanks. It's been stated that the tanks carry 500 pounds of oxidizer and 500 pounds of fuel, which means they are probably 30" tanks, whereas I think AA usually uses 36" tanks. The Mark II & III were qouted by Peter Diamandis as getting 2 minutes of propulsion. With this much propellant and a very rough ISP estimate of 220-270, this works out to 2000-2500 lbs thrust, what has been qouted multiple times.

The Velocity airframe has a Vne of ~200 knots, so assuming a weight of ~2700 lbs and thrust of ~2500 lbs, the vehicle should easily be able to sustain a climb rate of 100-150 m/s.

Again, this is a very rough estimate, but I would say the absolute minimum ceiling they could reach would be about 15,000 m, within 2 minutes.

lol of all the vehicles to have slipped my mind.
So far i've had not luck finding altitude and time-to-climb records for ground launched rocket planes (not launcehd from a mothership)
While it's really nothing more than a publicity thing, to be able to claim those would be a fun endeavor.