Green Hills' RTOS flies in Sikorsky S-92 helicopter

Rockwell Collins has integrated the INTEGRITY-178B real-time operating system from Green Hills Software into the Sikorsky S-92 helicopter's new highly integrated avionics package.

Rockwell Collins has integrated the INTEGRITY-178B real-time operating system (RTOS) from Green Hills Software into the Sikorsky S-92 helicopter's new highly integrated avionics package. With a passenger capacity of 19-22, the S-92 is Sikorsky's newest medium-lift helicopter, designed to meet both civil and military requirements.

Rockwell Collins successfully completed its first S-92 test flight of the system on October 5, 2001, and since has accumulated over 300 hours of company flight tests. The new S-92 cockpit is designed for enhanced visibility and is equipped with an avionics package that provides the core of an open-architecture avionics suite for processing aircraft system information. Flight data is shown on four Collins multi-function displays, with a fifth display offered as an option. The company is also using Green Hills' AdaMULTI Integrated Development Environment (IDE) to develop the cockpit's flight software.

A Motorola PowerPC running INTEGRITY-178B and Green Hills' GSTART Ada run-time environment is being used in the helicopter's new Collins Avionics Management and Display system. The system provides the display and integrated management of primary flight data as well as presentation and management of navigation information for the S-92. It also provides flight management data, a digital map, weather radar, terrain information, and engine instrument caution and advisory system processing and display. Rockwell Collins will use INTEGRITY-178B and GSTART to achieve DO-178B Level A certification of the Avionics Management and Display system.

INTEGRITY-178B is an ARINC-653 compliant RTOS optimized for safety- and mission-critical applications that require security and fast, predictable response. Using hardware memory protection and an advanced two-level partition scheduler, INTEGRITY-178B provides complete time, space, and resource partitioning between applications operating on the same hardware platform. This partitioning effectively builds a firewall between applications and the kernel, preventing errors in one application from corrupting other applications or the kernel. The RTOS also provides protection and guaranteed resource availability in both the time and space domains, thereby enabling applications that have been assigned different DO-178B safety levels to run concurrently on the same processor as defined in ARINC-653. INTEGRITY-178B's ARINC-653 Application/Executive (APEX) interface provides a recognized standard interface between the operating system of an avionics computer resource and the application software.

The RTOS includes a simulator (ISIM) that enables programmers to develop and test their code on a PC or workstation without the need for target hardware. INTEGRITY-178B also features a real-time event analyzer (EventAnalyzer) that enables viewing of system and user events in a graphical display.

AdaMULTI 2000 IDE is integrated with the RTOS. Together with Green Hills' family of optimizing Ada 95, C, and C++ compilers, AdaMULTI automates all aspects of embedded software development, including editing, source-level debugging, program building, run-time error checking, version control, and code/performance optimization. AdaMULTI also features an advanced code coverage tool (GCOVER) that automates structural coverage analysis for application software, including the analysis of DO-178B Table A-7, Objectives 5, 6, and 7 (statement, decision, and MCDC coverage achievement).

- Ryan Gehm

Wind River technology on board PROBA satellite

Wind River System's VxWorks real-time operating system helps the European Space Agency's PROBA micro-satellite system to operate virtually unaided by staff on the ground.

The European Space Agency's (ESA) PROBA (Project for On-Board Autonomy) micro-satellite system—the first ESA spacecraft with fully autonomous capabilities—operates virtually unaided by staff on the ground with the help of Wind River System's VxWorks real-time operating system (RTOS). PROBA is currently in orbit 600 km above the Earth's surface, testing the validity of self-functioning space technologies and performing several scientific activities to monitor the Earth's health.

Spacebel, the subcontractor responsible for providing PROBA's flight software, chose Wind River's VxWorks operating system for PROBA because of its robustness and proven reliability on space missions, said Dominique Baudoux, Spacebel's Space Business Unit Program Manager.

PROBA was launched via rocket by the Indian Space Research Organization and sent into orbit on October 22, 2001. The satellite has a range of advanced capabilities and instrumentation, including the ability to observe the same spot on Earth from a number of different angles. It has already provided scientists with detailed environmental images through its compact high-resolution imaging spectrometer (CHRIS)—the main payload on board the spacecraft. Data from the lightweight instrument are sent automatically from PROBA to ESA's ground station in Redu, Belgium, allowing scientists to develop tools for environmental monitoring, forest cataloging, crop forecasting, and marine science.

Wind River's VxWorks RTOS controls all onboard functions of the PROBA satellite and helps enable PROBA to upload new versions of software as it orbits the earth. This functionality is based on Wind River's robust "incremental linking" technology. The scalability of the VxWorks RTOS also proved important, as the operating system memory footprint was reduced to a minimum while reliably controlling all onboard instruments, tests, and communications. The VxWorks kernel accounts for less than 10% of the total lines of code on board PROBA.

The PROBA satellite provides scientists with detailed environmental images of Earth—such as this shot of San Francisco—through its compact high-resolution imaging spectrometer.

"Wind River has a strong history in space exploration including major projects with NASA and other agencies like the ESA," said Steve Blackman, Director of Marketing for Wind River's Aerospace and Defense Business Unit. "Developers of spacecraft have been able to leverage Wind River's integrated, commercial-off-the-shelf software solutions and development tools to get to market much faster than by developing their own solutions."

During its projected two-year lifetime, PROBA will be performing a series of scientific and housekeeping activities that can be planned, controlled, and monitored by both the ground team and the satellite's onboard computer. Functions that will be tested for autonomy possibilities include scheduling and planning of scientific experiments; data collection; communications between PROBA, scientific users, and the ground team; management of routine satellite functions; and failure detection. Most satellites currently require interaction between the ground and the spacecraft to carry out similar activities.

- Ryan Gehm