GR translation: Attitude 8.11, Torpor, Undergraduate.

[Mike Jing]

P209.13-26   Well, no, Slothrop doesn’t see, not exactly. He hears
this sort of thing from Dodson-Truck nearly every time they get
together. The man just materialized one day, out on the beach in a
black suit, shoulders starred with dandruff from thinning carrot hair,
coming into view against the white face of the Casino, which trembled
over him as he approached. Slothrop was reading a Plasticman comic.
Katje was dozing in the sun, face-up. But when his footpads reached
her hearing, she turned on one elbow to wave hello. The peer flung
himself at full length, Attitude 8.11, Torpor, Undergraduate. “So this
is Lieutenant Slothrop.”
Four-color Plasticman goes oozing out of a keyhole, around a corner
and up through piping that leads to a sink in the mad Nazi scientist’s
lab, out of whose faucet Plas’s head now, blank carapaced eyes and
unplastic jaw, is just emerging. “Yeah. Who’re you, Ace?”

What does "flung himself at full length" mean?  And what is "Attitude
8.11, Torpor, Undergraduate."?  Military slang?  Rocketry jargon?
What?