Pegasus XL Development and L-1011 Pegasus Carrier Aircraft

The Pegasus air-launched space booster has established itself as America\u27s standard small launch vehicle. Since its first flight on April 5, 1990 Pegasus has delivered 13 payloads to orbit in the four launches conducted to-date. To improve capability and operational flexibility, the Pegasus XL development program was initiated in late 1991. The Pegasus XL vehicle has increased propellant, improved avionics, and a number of design enhancements. To increase the Pegasus launch system\u27s flexibility, a Lockheed L-1011 aircraft has been modified to serve as a carrier aircraft for the vehicle. In addition, the activation of two new Pegasus production facilities is underway at Vandenberg AFB, California and the NASA Wallops Flight Facility, Wallops, Virginia. The Pegasus XL vehicle, L-1011 carrier aircraft, and Vandenberg production facility will be operational in the fall of 1993. This paper describes the Pegasus XL vehicle design, capability, development program, and payload interfaces. The L-1011 carrier aircraft is described, including its selection process, release mechanism vehicle and payload support capabilities, and certification program. Pegasus production facilities are described

Payload Interface Guide for the Pegasus Air-Launched Space Booster

The Pegasus(tm) Air-Launched Space Booster combines an innovative approach to satellite launch operations with the latest in proven launch vehicle technology. Pegasus provides small satellite users with an exceptionally flexible and cost effective means of placing payloads into a wide variety of orbital altitudes and inclinations. Vehicle ground processing techniques and payload integration methods have been designed to provide small payload users with flexibility in satellite design and integration. This paper describes the Pegasus vehicle, provides information pertinent to payload design and outlines the steps involved in using Pegasus to launch a typical small payload

Pegasus Air-Launched Space Booster

The Pegasus Air-Launched Space Booster development program, begun in early 1987, has the objective of combining an innovative approach to satellite launch operations with the latest in proven launch vehicle technology. Air launch of small satellite payloads on Pegasus provides a substantial performance improvement over ground-launched systems and also offers new launch operations flexibility including the ability to launch directly into virtually any orbital inclination. This paper describes the overall Pegasus vehicle design and reviews those design aspects that influence the design and integration of satellite payloads

Orion: Design of a Small, General Purpose, Low Earth Orbit Satellite Bus

A low cost general purpose mini-satellite bus is being designed to support a wide variety of small scientific and commercial payloads. The design incorporates several innovative concepts intended to reduce construction, launch and operational costs. The design is compatible with the new NASA extended Get-Away-Special (GAS) canister and several small low-cost expendable launch vehicles. The satellite is 19 inches in diameter, 35 inches long and weighs approximately 270 Ibs. The satellite bus provides telemetry, attitude control, orbital boost/station keeping, electrical power, microprocessor and data storage for up to 50 Ibs. of user payload . The hydrazinc propulsion system provides up to 2600 ft/sec delta-V capability. The availability of on-board propulsion reduces launcher orbital insertion accuracy requirements, provides for stationkeeping and is sufficient to allow the satellite to independently achieve 800 nm circular or 2200 nm elliptic orbits from an initial 135 nm orbit. The design stresses simplicity, ingenuity, and utilization of previously proven and high quality commercial components. Manufacturing costs are reduced by using simple design practices and simplified test procedures. Total cost for the satellite is projected to be less than $1.5 million. Orion will be ready for launch in 1990

Pegasus First Mission - Flight Results

On April 5, 1990, after release from the wing of a B-52 carrier aircraft over the Pacific ocean at an altitude of 43,198 ft, the three stage Pegasus solid propellant rocket successfully completed its maiden flight by injecting its 423 lb payload into a 273 X 370 nautical mile 94 degree inclination orbit. The first flight successfully achieved all mission objectives; validating Pegasus\u27s unique air launched concept, the vehicle\u27s design, as well as its straightforward ground processing, integration and test methods. This report summarizes the results of the first launch, including measured vs. predicted motor performance, drag and lift coefficients, payload environmental parameters, structural loads, aerodynamic heating, and vehicle trajectory. In all areas, measured flight results were close to design predictions, and in the ease of the actual payload environment, were significantly less than predictions. The Pegasus first flight validated the fundamental aerodynamic design, established a baseline performance capability, validated the vehicle\u27s GN&C system, and validated the aerodynamic and aero-thermal models

Whither or wither microbicides?

After disappointing results from all efficacy trials conducted to date, the field of microbicides research now faces substantial challenges. Poor coordination among interested parties and the choice of nonvalidated scientific targets for phase III studies have hampered progress and created mistrust about the use of microbicides as a method to prevent HIV-1 sexual transmission. Although new promising strategies are available, there will need to be serious reappraisals of how decisions are made to advance the next generations of candidates into clinical trials, and the use of appropriate animal models in this process will be critica