Clearwater, Fla. — Officials at Lockheed Martin Space Systems in Sunnyvale, Calif., have contracted Honeywell Space Systems engineers in Clearwater, Fla., to deliver fault tolerant inertial navigation units (FTINU) for the Atlas V Launch Vehicle.
Fault tolerant inertial navigation units from Honeywell Space Systems perform inertial measurement functions, as well as provide the processing for flight control on the Atlas V rocket.
Honeywell's contract is worth more than $52 million over the next seven years and includes options for an additional $72 million in orders. Under the new contract, Honeywell will deliver development and flight units.
"This next generation high accuracy launch vehicle inertial navigation system provides robust fault tolerance in all functional areas," says Lee Williams, vice president of Honeywell Space and Strategic Systems. "This design incorporates advances in component technology and onboard computing to allow rapid high confidence fault detection and isolation without compromising mission accuracy."
The FTINU is the primary avionics component for a launch vehicle guidance navigation and control subsystem, Honeywell officials say. It will perform the inertial measurement functions, as well as provide the processing for flight control software.
The main advantage of the FTINU is its redundancy in design, says Joe Wright, program manager for the FTINU. It has five Honeywell GG1320AF ring laser gyroscopes for angular rate sensing and five Honeywell ISO-COIL2000 pendulous gas filled linear accelerometers for acceleration sensing. Only three of each sensor is necessary to operate the unit, he adds.
Previous units only came with three ring laser gyroscopes and three accelerometers, so a failure caused an immediate problem, Wright continues. Now, with the FTINU, users can lose two gyroscopes or two accelerometers and the unit continues to function, he explains.
Inside the device is a Honeywell 1750A processor with 1553 interfaces, Wright says. The software is designed by engineers at Lockheed Martin and is written in the Ada programming language, Wright says.
Honeywell engineers in Minneapolis design the ring laser gyroscopes, which are the same ones used on the International Space Station, he says.
The FTINU is based on Honeywell's next generation Redundant Launch Vehicle Guidance Unit, which is to serve as replacement for existing non-redundant systems, Wright says. The RLVG, which is still currently in development, features a Honeywell programmed inertial processor providing sensor compensation and fault tolerance and a user programmed flight computer providing vehicle control over standard 1553 interfaces, he writes in a white paper on the product.
"The RLVG is designed as a primary avionics component for a launch vehicle guidance, navigation, and control subsystem," Wright states in his white paper. "It performs the inertial measurement functions, as well as provides the computer processing capability for ground and flight software and all the input/output interfaces necessary for the ground and flight software.
"The RLVG consists of two principal functional subsystems, a strapped-down inertial measurement subsystem, and a flight control subsystem," he writes. The IMS and FCS subsystems are controlled by a MIL-STD-1750A compliant, radiation-hardened chipset, Wright states.
