The RSI is the result of an effort to both enhance performance and modernize the KSC Launch Processing System’s Simulation Interface to the firing rooms (refer to the Research and Technology 1999 Annual Report). The RSI is a replacement and complete redesign of the Video Simulation Interface (VSI), which has performed as the simulation interface to the firing rooms since the start of the Shuttle era. The RSI was designed not only to meet and exceed current VSI specifications but also to incorporate maximum flexibility to meet future requirements. The core design of the RSI incorporates a highly compliant architecture, which will facilitate future enhancements. One of the primary goals in the new design was to remove dependencies upon specific hardware whenever possible. To that extent, the VxWorks operating system was chosen for its broad-based hardware compatibility. Primary data communication between the various elements of the RSI utilizes a 13-megabyte-per-second optical fiber transport between reflective memory PCI bus cards. This feature allows daisy chaining and system expansion to multiple chassis for scalable functionality. As shown in the figure, the RSI core is based on a 21-slot VME chassis that contains a hybrid mix of boards. A Force Sparc CPU-50 VME Single Board Computer (SBC) running Solaris is used as the system controller. There is also a second Force Sparc VME board, which functions as the Simulation Executive (KSC Simulation System Sim-Engine), running under Solaris. This board contains a Reflective Memory (RM) PCI Mezzanine Card (PMC) for the Simulation Executive and Model communication to the other RSI elements in the chassis. These elements consist of a set of Simulator Processor Units (SPU’s) that are running the VxWorks operating system on Motorola PowerPC’s. Each of these SPU’s, in turn, can host up to six PMC’s, one of which is an RM card. The RM allows data sharing and coherency between the SPU’s and the Simulation Engine. The other five cards on each SPU are Generic Simulator Cards (GSC’s), which perform Shuttle and ground system data flow emulation. Each GSC is dynamically configurable to emulate a Shuttle Downlink pulse code modulation (PCM) stream, Ground Data Bus (GDB), or Launch Data Bus (LDB). The RSI can also function as a Shuttle PCM Uplink simulator using a Berg Bit-sync VME board. Lastly, each GSC is based on a TMS320 Digital Signal Processor (DSP), which enables the card to be programmed to emulate data protocols to support future vehicles, payloads, and even nonspace-based systems.

Essentially, the RSI is a portable, self-contained simulation interface with a built-in simulation engine. The RSI can interface to the firing rooms, as well as function within a hardware-in-the-loop simulation environment such as the Kennedy Avionics Test Set (KATS). In this type of environment, the RSI is used to handle data transmission to and from real hardware such as the Shuttle General Purpose Computers (GPC’s). In this mode of operation, the RSI has been designed to handle commands and requests for data from the GPC’s in as little as 5 microseconds.

Real-Time Simulation Interface (RSI), 21-Slot Chassis

Key accomplishments (2000 – 2001):

• Completed the proof-of-concept investigation of real-time Linux.
• Moved into full capability development with VxWorks for device drivers.
• RSI connected to the Checkout, Launch, and Control System (CLCS) Gateway for hardware testing. (RSI was connected to a Gateway [a new CLCS firing room element] test fixture and successfully displayed correct data from an RSI-generated 128-kbit/sec PCM telemetry stream containing Orbiter Instrumentation bus-formatted data.)

Key milestones (2002):

• RSI GDB and LDB elements 90-percent complete.
• RSI validation scheduled for July 2002.
• Deployment of the first elements of RSI scheduled for September 2002.

Contacts: G.S. Estes (Scott.Estes-1@ksc.nasa.gov), YA-E1-S4, (321) 861-2403; and C.T. Lostroscio, YA-E1-S4, (321) 861-7286
Participating Organizations: NASA YA-E1-S4 (C.M. Alvarado, J.M. Busto, K.J. Grant, C.G. Lehan, and N.G. Taylor); Dynacs Inc. (J.H. Celsor); and United Space Alliance (J.J. Howell)