SdKfz 251/c Launching rockets

[groundlber]

I've looked through my reference material; All agree the rockets were single fired. One book had a medium quality photograph of a 251 firing. What appears to be the last rocket was fired from the right side, and the sequence was long enough there weren't multiple smoke trails. Hopefully someone else may come up with some better information.
Good luck.
Groundlber

[ZMONSTER]

I might be reading into this a little much, but because a half track depended on its front wheeled axle for some of its steering, if not all. Firing the rear most rockets first would ensure the vehicle stayed balanced if it needed to move. Also, firing the rear rockets first would not apply as much thrust forces to the other loaded rounds. And with their 1-3 km range these weapons were a tactical tool that would depend upon a concentration of two or more vehicles all aimed on intersecting azimuths.

I would also assume this vehicle was fired remotely, as a firer would not want to be in an open topped vehicle during launch; much less any were near, as these rockets could probably explode in their launchers. Our MLRS troops have an armored cab that is sealed tight during firing to keep out the poisonous fumes from the rocket firing.