VirtualSat
Spacecraft Dynamics
& Real-time Simulator
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The VirtualSat system is a spacecraft dynamic simulator offered by the
Hammers Company, Inc. VirtualSat is a simulation environment hosted
on a PC specifically geared to facilitate the design, development,
and test of flight software written in C or C++. VirtualSat provides
simulation of dynamics, sensors, actuators, multiple spacecraft with
interfaces to ground support equipment (GSE), flight processors,
actuators and sensors in real-time, faster than real-time, or
single-step debug modes. VirtualSat is currently supporting THEMIS,
ST-7 Mission for Disturbance Control Reduction, LWS SET-1, EO-1,
NEMO, SWIFT-BAT, and commercialization of the SMEX-lite flight
software. Utilizing low cost commercial hardware I/O devices,
VirtualSat provides a hardware-closed loop
development and test
capability for flight software development and verification.
VirtualSat is unsurpassed in providing a realistic spacecraft
training facility for a flight operations team. In addition to full
CCSDS flight software support, VirtualSat can support third party
components for simulations through a wizard interface. VirtualSat
supports a PC desktop or laptop environment and provides plotting,
data archive, and scripting capability.
VirtualSat acts as a blank slate allowing software developers, testers, and control analysts unlimited options in configuring simulation environments to meet their specific needs. A spacecraft simulation can be built in minutes using pre-defined basic components and assigning characteristics such as mass properties and sensor & actuator configurations. VirtualSat can be controlled through its own console window or remotely via an Ethernet connection to a variety of GSE devices. Data from VirtualSat can also be sent to and displayed on these devices. ‘Standalone’ incorporates the spacecraft dynamics simulator with the spacecraft flight software or with other modeling software (i.e. - thermal or power models).This allows flight software developers and software test engineers an opportunity to debug/analyze/unit test flight software. It also allows spacecraft control analysts and flight operations team an opportunity to understand the behavior of the flight software/spacecraft in different configurations.
VirtualSat simplifies spacecraft test and integration efforts...
The virtual environment supports single-step, real-time and faster-than-real-time code execution modes providing faster development and test and the dependency on hardware availability.
In a ‘hardware-in-the-loop’ environment for real-time testing, interfacing directly with processors, sensors, and actuators allows the same spacecraft dynamics and simulation environment to be used throughout the spacecraft life cycle.
VirtualSat provides tools to streamline modeling of a spacecraft or any other dynamic object. The architecture allows individual components to simulate spacecraft dynamics, act as sensors and actuators, and even host flight software. The components can be reproduced to allow VirtualSat to simulate multiple spacecraft in a formation flying configuration. VirtualSat supports user configuration of components in real-time. With its support of interfaces to GSE equipment, the configurations and simulations can be script-controlled, supporting regression testing based on time and/or events. VirtualSat has currently been interfaced with both the ITOS and ASIST spacecraft command and telemetry systems from NASA.
VirtualSat is hosted on commercial-off-the-shelf (COTS) hardware, using standard Windows-based PC configurations and supporting a variety of off-the-shelf interfaces to allow for a wide array of configurations. VirtualSat can be configured with Mil-Std 1553, 1773, 232/422/485 serial devices, and GPIB hardware. Recent advances now include SpaceWire interfaces. New components can be easily added to support custom hardware interfaces.
Flexibility available in VirtualSat configurations and interfaces…
Provides the user with the ability to thoroughly test spacecraft software and hardware systems.
VirtualSat supports injected simulated failure conditions during run-time to test system response and failure recovery.
Simulated failures can be injected through external GSE such as spacecraft command systems or directly from the VirtualSat user interface.
VirtualSat timing capabilities...
VirtualSat has supported missions using control cycle rates of up to 10Hz, and simulation cycle rates of up to 100Hz.
Selected components can run under the RTXTM OS for µsec-level resolution.
VirtualSat also supports external time synchronization. The Hammers Company's XHz external timing card is also available for customizing rate selection.
