A Throttling Solid Propellant Rocket Motor with Adaptive Thrust Control

Period of Performance: 04/12/2006 - 04/30/2008


Phase 2 SBIR

Recipient Firm

Propulsion Research, Inc.
651 Southview Court, Unit H
Culpeper, VA 22701
Principal Investigator


This proposal outlines a Phase II program to define and develop a throttling solid rocket motor (SRM) with enhanced performance capability and minimum 15:1 thrust turndown that will provide total thrust management capability for tactical missile applications. The program will focus on improving delivered pintle motor performance. One primary approach will use a new type of pintle nozzle system that shows promise in vastly reducing the low thrust coefficient efficiency that is characteristic of sonic pintle nozzle systems. Other performance improvements will include major reductions in pintle size and weight, the demonstration of an externally mounted pintle drive system, and the addition of multi-pulse ignition capability into the pintle controller hardware and software. The adaptive control techniques will interface with the variable area pintle nozzle system to provide closed loop control capability with the built in intelligence necessary to provide "on-demand" thrust control to the missile. PRI will use its "smart-thrust" adaptive control technology to achieve optimal control during the ignition transient phase as well as all other areas of motor operation. Multiple static tests will be conducted to validate the delivered performance of the pintle motors using class 1.3, IM, minimum smoke, high performance propellants. Consensus will be sought between the sponsor, prime missile contractor, SRM manufacturer, and PRI to arrive at the test objectives to be demonstrated that will best benefit future tactical missile systems.