Average
Velocity
Is
Meaningless
To
This
Entire
Question
I'm blindingly confused by all of this. But agree with you. Why would average velocity matter in the slightest? Isn't the only velocity of concern what it is at engine cutoff, 16000km/h? Who cares what happened between 0 and 16000, the latter is the only figure that matters.
I know this has come up a dozen times all ready, but the metaphor seems to be a bullet leaving the barrel of a gun, that velocity and a whole host of other factors, drag, trajectory, g and such, determine the distance and/or altitude traveled. I kind of think of it as the ballistic missile is fired out of a barrel that 250 km high at engine cut-off. The question becomes, just like the bullet out of the barrel, how far/high will it travel from that point on. Not what happened in the "barrel".
And like I pointed out earlier, which was considered a strawman, which it is not, is that a dozen plus parameters all enter into the calculations to figure that out. It's very, very complicated to say the least.
When the projectile hits engine cut-off at 16000km/h at an altitude of 250k and g of 9.08, having all its fuel burned off, take-off weight of the HS-15 is estimated at approximately 73 to 74t or 67000 kilos. Propellent for the 2 stages estimated to weigh 67 tons or 60000 kilos. So the projectile at cut-off now weighs 7000 kilos traveling at 16000km/h - That is your bullet velocity and some elements to be concerned with.
With that, if it continued up to let's say 500 km post cut-off, our 7000 kilo bullet would be experiencing g of now 8.43.
The question is how fast is our bullet going now?
if it continued up to let's say 1000 km post cut-off, our 7000 kilo bullet would be experiencing g of now 7.32.
The question is how fast is our bullet going now?
Let's say it kept going up to a whopping 2000 km post cut-off, our 7000 kilo bullet would be experiencing g of now 5.68.
And so on. And that's just factoring in a one, gravity, of the many elements needed to accurately calculate just how high it could go from a 16000km/h speed, 7000 kilo mass starting point.
So I agree, to even mention an average is absolutely meaningless. Is there something missing?