Das englischsprachige Wikipedia beschreibt die Gründe für das automatische Shuttle-Rollprogramm aktuell wie folgt:
"During the launch of a space shuttle, the roll program is simultaneously accompanied by a pitch maneuver and yaw maneuver.
The roll program occurs during a shuttle launch for the following reasons:
To place the shuttle in a heads down position
Increasing the mass that can be carried into orbit
Increasing the orbital altitude
Simplifying the trajectory of a possible Return to Launch site abort maneuver
Improving radio line-of-sight propagation
Orienting the shuttle more parallel toward the ground with the nose to the east"
NASA beschreibt die Gründe so:
"Ascent Guidance and Flight Control Training Manual":
"During the vertical rise phase, the launch pad attitude is commanded until an I-loaded V(rel) sufficient to assure launch tower clearance is achieved. Then, the tilt maneuver (roll program) orients the vehicle to a heads down attitude required to generate a negative q-alpha, which in turn alleviates structural loading. Other advantages with this attitude are performance gain, decreased abort maneuver complexity, improved S-band look angles, and crew view of the horizon. The tilt maneuver is also required to start gaining downrange velocity to achieve the main engine cutoff (MECO) target in second stage."
Das mit der Sicht auf den Horizont scheint für den Notfall wohl hilfreich.
Gruß Pirx
