Airborne Launch: A zero-pressure balloon lifts the Instrumentation Platform, Launch Vehicle and Satellite above 25 km (80,000 feet). All systems are checked during a brief period of hovering and count-down. Then, the launch vehicle and satellite are released and a few seconds later the first stage ignites. After clearing the balloon envelope under the control of its Inertial Guidance System, the launch vehicle pitches up to 90° until it clears 100 km. Then, it pitches gradually back to 0° as it approaches orbital speed. The satellite is deployed in a Low Earth Orbit between 200 and 400 km.