2 x 180 deg roll
The 2x 180 roll observed on 2 of the simulation videos could be related to some of the following scenarios (?):
(a) After rocket stage burn-out high up in thin air the near-zero g is leaving LH2 fuel in tanks floating freely, roll manoeuvre centrifugal g facilitates fuel being taken from tank to supersonic combustion chamber; after scramjet ignition roll-on to nominal attitude is required for intake aerodynamics and lift aerodynamics.
(b) First roll manoeuvre facilitates mechanical unlocking of rocket stage after burn-out, second manoeuvre as under (a).
(c) Assuming actual roll manoeuvre timings to be possibly different from shown in videos: in the initial rocketed phase increased-g pull-up trajectory the scramjet intake is required on bottom of vehicle for aerodynamic reasons, in the later rocketed phase negative-g levelling-off trajectory the intake is required on the opposite side, in the scramjet propelled near-level flight trajectory the intake is again required on bottom of vehicle.
(d) Artist´s liberty.
Just guesswork, curious to hear anyone´s other ideas.
JR
Last edited by janrein; 22nd September 2012 at 06:37.
Reason: correcting typos