Tweet

Countdown Timeline

Time (T-)	Event
T-4:15:00	Ground Operation Checks complete
T-3:15:00	NASA Launch Team - Management on Station
T-2:20:00	Flight Crew enters L-1011 Aircraft
	Prestart Checklist (L-1011)
T-2:18:00	Engine Start Poll
T-2:10:00	GO for Engine Start
	Start Engine 2
	Start Engines 1&3
	Aircraft Hatch Closure
	Aircraft Stairs Removal
T-1:45:00	Pre-Taxi Checklist complete
	Flight Termination System Activation
	Voice Checks completed
T-1:15:00	GO for Taxi
	Taxi
T-1:03:00	Status Check
T-1:00:00	Ready for Takeoff Poll
	GO for Takeoff
	L-1011 Takeoff
	Chase Plane Takeoff
T-0:30:00	Chase Plane Visual Inspection
	Report on Turbulence, Winds, Clouds
T-0:15:00	Release Mechanism armed
T-0:12:00	Flight Termination System Verification
	Avionics to internal Power
T-0:09:00	Weather Status Report
	Weather GREEN for Launch
	Peak Power has Passed
	L-1011 on Course to Drop Point
T-0:07:00	Range Status Validation
	Transient Power on
	Verify Vehicle is safe
T-0:05:00	NASA Launch Manager - Final Status Check
	Avionics on internal Power
T-0:00:45	Fin Battery Activation
T-0:00:20	Fin Status Check
	Fin Heading Status Verification
T-0:00:10	Pilot confirms GO for Launch
T-0	Pegasus release
T+0:00:05	Pegasus Orion 50S IGNITION

Ascent Timeline and Ground Track

Time	Event	Altitude
T-0	Pegasus Release	11.89km
T+0:00:05	Orion 50S Ignition	11.79km
T+0:00:08	Pitch Maneuver	-
T+0:01:17	First Stage Burnout	54.25km
T+0:01:30	First Stage Separation	-
T+0:01:32	Orion 50 Ingition	71.63km
T+0:02:08	Payload Fairing Separation	115.21km
T+0:02:45	Second Stage Burnout	180.14km
T+0:08:55	Second Stage Separation	-
T+0:09:06	Orion 38 Ignition	620.79km
T+0:10:14	Third Stage Burnout	629.68km
T+0:13:14	Spacecraft Separation	-
	End of Pegasus Mission	-
	L-1011 Returns to Departure Point	-

Launch Date	June 13, 2012
Launch Time	15:30 to 19:30 GMT
Launch Site	Air Launch
	Ronald Reagan Missile Defense
	Test Site, Kwajalein Atoll
Launch Vehicle	L-1011 Aircraft
	Pegasus XL

Launch Vehicle

Photo: NASA

>>> Pegasus XL Launch Vehicle Information

Launch Site

Photo: NASA

Insertion Orbit

Apogee	575 Kilometers
Perigee	600 Kilometers
Mean Altitude	587.5 Kilometers
Inclination	6°
Semi Major Axis	6,950 Kilometers

Photo: Orbital Sciences Corporation

Launch Window Opens

---