The assumption is made (by Estes) that with the delay, the MAX LIFTOFF
WEIGHT would be less, due to the longer delay, and resultant ballistic
trajectory could be avoided.
In other words, if you used a model that needed just the 3-second delay to
eject at apogee, then a 5-second delay would probably strip the chute,
and quite possibly, a 7-second delay would "lawn-dart" into the ground,
destroying the rocket (just before the "POP!" of ejection.. ;^ ). The
booster has a higher rating because it has NO delay and thus is moving
much faster (greater momemtum) at staging. Recovery is not considered for
the -0 booster engine.
So what you are seeing is cautionary overkill by Estes. Use your own good
judgement.
David.
David A. Butcher
Sr. Global VSAT Support Engineer
AT&T Tridom 1-800-874-3666,
ext. 770
840 E. Franklin Court, 1-770-514-3770
Marietta, Georgia, USA 30067-8946
PGR: 1-800-SKY-PAGE, PIN # 2885987
FAX: 770-429-5417 or 770-795-2132
HPR - Shoot for the Stars! ...and Blue Skies to 'Ya.