If the Moon or Mars will we . . .

Ok, but wouldn't then be possible to take advantage of this in another way?
For example one could make a rocket with small wings, you can take it up to
say 15k meters by balloon airship, then let it drop a good 5k meters, at
which point it would have acquired some considerable speed, virtually free,
and could perform a gliding turn upward, then ignite and shoot back up?
At a very rough calculation, assuming no air drag*, it should manage to
accelerate to over a thousand kmh in 5k meters, and still be outside the
first 30k feet of most dense air. *there will be of course some air drag,
but on an aerodynamic shape at that height should be negligible, or do I
underestimate that? Even considering the speed will be greatly reduced by
the turn upward, the combined factors should considerably reduce the amount
of fuel required... even if it will loose nearly all speed doing a
relatively gentle turning, and will be only going at say 4-500 kmh, 30k feet
high, at ignition, did the whole first stadium of a Saturn achieve much more
than that in terms of altitude and acceleration, the actual lift off being
the most expensive and less efficient part of a launch...?
The wings could be jettisoned as soon as the upward turn is complete, and
like the airship lifter could be recovered and reused. In theory would
sounds a lot cheaper than strapping two solid rocket fuel booster to the
side... maybe could be even done with the shuttle, do you think NASA would
lend me one to try it out? :)
Isn't the same principle applied in space navigation for slingshot
manoeuvres using planets gravitational attraction to gain speed? In a much
smaller scale admittedly... ;)