Inertial guidance system for low earth orbiter (LEO) vehicle

A low-cost, high-precision inertial guidance system now being developed for the Low Earth Orbiter, a commercial space launch vehicle, is described. The system consists of a Roll-Stabilized Inertial Measurement system (RIMS IV) and an Advanced Digital Guidance Computer (ADGC); the system is also applicable to sounding rockets. The RIMS IV is a precision roll-stabilized strapdown system which provides the body-fixed attitude rates and acceleration data to the ADGC. The ADGC is a multiprocessor system which uses two Intel 16-bit 8086 processors in conjunction with an 8087 math coprocessor; it performs on-board processing of all the RIMS IV data and generates the commands required for vehicle control. The development history of the inertial system and the work currently performed to complete the required software are discussed along with potential applications.