Peter Stickney wrote:
[ACES...]
Sounds like they're going for a LOX Squeezer. If you can get enough
air in, and enough ram compression, supposedly you can squish some
LOX out of the air. It's a pretty old idea - the same techniques was
proposed in the late '40s/early '50s to squeeze out Methane to use as
fuel.

Sounds like the variation is to do it at low speeds to use later in
high speed flight.

They want low* vehicle weight at takeoff because they are rolling down
a runway.

*relatively speaking

/dps