1405
hours
`` Request blast-off orbit and clearance ! '' The traffic-control officer in the spaceport tower answered immediately . `` Control tower to _ Polaris _ . You are cleared for blast-off at 1405 hours , orbital tangent 867 . '' Tom repeated the instructions and turned to the intercom and began snapping out orders . `` Power deck , energize the cooling pumps ! '' `` Power deck , aye ! ''