Pegasus — Past, Present and Future

Abstract

On the morning of 5 April 1990 the Pegasus launch vehicle embarked upon its maiden voyage to place two small satellites into a 593 × 667 km orbit inclined at 94 degrees. A specially modified NASA B-52 took off from Edwards Air Force Base with the Pegasus rocket attached to its right wing and headed NW over the Pacific Ocean to its pre-determined launch point. After confirmation that all systems were “go” the 14.9 m, 18,800 kg rocket was released from the carrier aircraft and, twelve minutes later, became the first privately developed rocket to place a satellite into Earth orbit successfully. Since that time, the Pegasus program has conducted 30 missions launching over 70 satellites for both government and commercial customers. Many of these missions have included multiple satellite deployments. The vehicle has been upgraded to include an extended length (XL) configuration (16.8 m long, 23,100 kg) for added performance, an optional liquid fuel fourth stage for improved injection accuracy, and a new L-1011 aircraft. In addition a new flight computer, inertial navigation unit, new reaction control thrusters, and subsystem batteries have been incorporated. Many other components have been upgraded from the original configuration.

Currently, the Pegasus program focuses on vehicle enhancements that will continue to make Pegasus the most reliable small satellite launch vehicle in the world. New business opportunities outside the normal satellite launch industry are being pursued; these include quick reaction launch capability and technology demonstrations for the NASA Space Launch Initiative. The paper reviews some of the highlights of the past 11 years and also the current developments and activities for the coming years, especially in relation to launching small satellites.