In between 85-100Km altitude I'll wind up shutting down the mains and coast uphill. So like I said, I think we're pretty much on the same page as far as our methodology.
Yes, unlike most modern multistage rockets or the Space Shuttle/Buran configuration, the DeltaGlider has a very impressive T/W ratio, and of course it gets better and better as you burn fuel.
So that's really the way to go :
- a sharp takeoff more in the military than the in civil fashion, because you want to get out of the dense atmosphere that slows you down as fast as possible (but you want to use the lift generated by your wings, so it's a matter finding a good tradeoff between dynamic pressure and generated lift). The acceptable dynamic pressure range is between 8kPa and 20kPa (I'd say 10-12kPa is quite optimal for the standard DG). Below 8kPa the airflow is insufficient for the wings to generate lift, and you stall. Above 20kPa the friction of the air molecules gets really strong and you are wasting a part of your fuel heating your spacecraft leading edges (which is bad !).
- Once above 10km you can begin to pitch down a bit to gain some horizontal speed, and should cross the 20km mark over Mach 3.
- At this point, the key is again to watch the dynamic pressure (if it rises too much, pitch up). Then as wrote PhantomCruiser at some point you're on a "X-15 like" suborbital trajectory that brings you on the edge of space (100-120 km).
- When the Apoapsis in the Orbit MFD gets into that range, this is definitively a good idea to shut the engines down, enjoy the scenery and use this time to calculate the lenght of your orbit insertion burn
Don't start it too like, or you might fall back into the atmosphere which will brake (and break) you.
- You perform the Orbit Insertion burn. 100-120 km is still low enough for the rare air molecules to slow you down in a matter of hours, so aim for 250km, and once there circularize (try to get an Eccentricity as close as 0 as you can).
- From there, you are safe and have enough time to plan the next phase of your flight (for rendez-vous, its necessary to plan things before taking off
).
