@vincent13031925 Final decision made earlier this week on booster engine count. Will be 33 at ~230 (half million lbs) sea-level thrust. All engines on booster are same, apart from deleting gimbal & thrust vector actuators for outer 20.
@Undetermined_US@elonmusk@vincent13031925 In my opinion real reason is to develop rocket technology and sell it. Mars colonizing idea is good marketing for building hype.