Orbital ATK’s Pegasus rocket gets its payloads into space just like a conventional rocket, but instead of lifting off from the ground, the Pegasus starts its trip already in the air. That’s because a modified L-1011 airliner carries the Pegasus and its payload – CYGNSS in this case – to about 39,000 feet. Pegasus begins its solo flight by being released from the belly of the airliner.
Five seconds of free-fall ends when the solid-fueled first stage ignites. With its main, delta-shaped wing providing lift and a rudder and elevators on the back steering, the Pegasus noses up quickly and heads into orbit, discarding its first stage after leaving the thick portion of the atmosphere. The second and third stages, also burning solid propellants, take over to place the satellites in their prescribed orbit. Here’s a look at what makes the Pegasus flights different: