QUOTE (djellison @ Jan 24 2006, 01:51 PM)
The Atlas V 551 uses 5 solid rocket motors + the RD180 engine, so considerably more than half the thrust at launch comes from solid motors.
Doug
Doug
Thanks Doug, that is correct, it is the core of the 'zero' stage that is liquid, the five strap-ons are solid.
Minor aside here: As NASA scrambled for a replacement for the shuttle, they ask both Boeing and Lockheed to prepare a list of viable options. Boeing retorted that only their stack would work, Lockheed said only theirs would, so NASA decided to do their own study and concluded that since both stacks involved a cadra of solids, providing most of the thrust, why not just elliminate the liquid core and go with a solid first stage?