In today's crash, seen below, there was a control operator who stated, right as the rocket blew up, "Avionics Power nominal". What does that mean exactly? Was he referring to the rocket power, power to a computer, or something else entirely?
Avionics is short for "aviation electronics"; on an aircraft it can include computer equipment, communications, guidance and navigation, radar, etc. "Avionics power nominal" implies that the rocket's guidance computers were getting the right amount of electrical power.
Presumably the Antares rocket's avionics power went off-nominal a short time later, perhaps when it hit the ground.