On Tue, May 28, 2019 at 7:05 AM Nels Anderson <nels.anderson@xxxxxxx> wrote:
On 5/27/19 2:50 PM, Keith Henson wrote:Gravity Losses are a function of Time, so flying to orbit with an
The not-so-obvious thing they do is using the wings to unload gravityHow incredible could the savings be? Total losses, not just gravity,
drag. They do this even after the switch to rocket mode. The wings
save an incredible amount of delta-v compared to a rocket that took as
long to get to orbit.
for a conventional rocket to LEO might be 1000 m/s out of a total ideal
delta-V of about 9000 m/s. Saving a significant fraction of that 1000
m/s ain't peanuts if you're operating well into the rocket equation's
exponential regime, where a rocket-powered SSTO . But given how lousy
hypersonic L/D's, I would think it's almost as much a matter of trading
gravity losses for drag losses as saving gravity losses.