COSMOS Operations Testbed

The COSMOS Operations Test-Bed (OTB) uses an open-source system architecture that integrates hardware and software components and tools to operate a low cost Satellite System Simulator (e.g. FlatSat) which can be integrated into the MOC setup for command scripting testing, personnel training, mission rehearsals and anomaly resolution. The OTB has tools for satellite technology integration and development that allows for cheaper satellite subsystem integration and testing. The OTB tools are based on COTS that are affordable to university labs while some tools are being developed under the COSMOS project using proven standards and made available to the small sat community. The OTB is part of the four major processes in mission operations that are supported by COSMOS, namely the Mission Planning and Scheduling, Real-time contact operations, mission analysis, and anomaly resolution.

The OTB will be initially used within the Hawaii Space Flight Laboratory small sat development program and after a successful implementation and usage it is expected to be installed in other facilities, like other universities, within the COSMOS project umbrella.
One important aspect of the OTB is that it makes possible to provide an interface with different satellite hardware and simulators that are needed to make the global testing procedure for different missions. This platform also allows the mission segment functional simulation and mission rehearsals from the command sequence to the software and hardware performance.
To completely operate the OTB its setup must integrate six main constituents: (1) The actual Mission Operations Center (MOC) control tool, or MOST; (2) the Ground Station Simulator (GSS); (3) the Satellite System and Subsystem Simulator (SSS); (4) the Test Bed engine (TBE); (5) The test bed controller tool (TBCT); and (6) the Test bed controller user interface. This segmentation is expressed in Figure 5.
The MOC System Simulator allows the end user to conduct the near real-time spacecraft system and subsystems testing and operational activities, including mission planning; assessment and maintenance; instrument health monitoring; and communications, command and control function. The integral part of the
MOC System Simulator is MOST, which is one of the two interface tools between the OTB and the end user.

Figure 5 - OTB Functional Block Diagram
MOST is connected to the second main component of the OTB – the Ground Station Simulator (GSS). The GSS receives simulated or real telemetry from the satellite system that is at remote location. The communication link for the test bed is based on Ethernet layers supported on concurrent communications software to allow real time and high performance communication services with standardized procedures and portability between different OS platforms. Open source frameworks for network communications are considered as primary resources for the development of the OTB. Serious options being considered and partially used in the OTB are the Adaptive Communication Environment, also known as ACE and the Lightweight Communications and Marshaling, or LCM, which is targeted to be used in real-time systems where low latency are critical and high bandwidth are important. The communication link may also use the actual Telecommunications subsystem of the satellite by interfacing with standard software and hardware protocol layers for reliable communication.
The Satellite System and Subsystem Simulator platform integrates all the satellite subsystems to be operated (e.g. ADCS, TCS, EPS, Telecom, etc.). These can be either fully operational with the engineering model hardware components or else software simulated if the hardware components are not readily available. This platform receives data from a simulated Telecom subsystem or the On Board Computer Subsystem (OBCS) engineering model. The OBCS will change accordingly to each mission that utilizes the OTB as well the other satellite subsystems, but each has standardized software and hardware features. The satellite system will then provide the data commands and any data relevant to the surrounding system. Based on the Test Bed Engine, it supports full propagation of the test satellite’s conditions, in both real and faster than real time. Figure 6 shows a subsystem of the OTB being tested for development of the On Board Computer System for the HawaiiSat-1 microsatellite. Figure 7 shows the HawaiiSat-1 full-scale mockup being used to test a reaction wheel on the OTB by using MOST to connect through a GSS to the mockup.
Figure 6 - HawaiiSat-1 OBCS in OTBFigure 7 - HawaiiSat-1 Mockup Used in OTB
The Test Bed Dynamics Engine provides a software simulated space environment to the OTB to allow a more realistic operation of the whole platform. It has a Space Dynamics Engine for orbital data generation and a Space Environment Simulator that integrates different physical models like the atmospheric models, the magnetic field model and others. The dynamical engine also controls the different hardware and software configurations in the satellite system simulator and allows the tuning and mixing of signals and interrupts, adding noise and possible failure modes. All this is done either controlled by the controller user interface or a scripting sequence.
The Test Bed Control Tool (TBCT) is an application to support the experimental set up for the OTB architecture. The TBCT interfaces with the GSS, the satellite system, the Test Bed Engine and the end user. It allows initializing and controlling the satellite system platform and the Test Bed Engine according to the user decisions or scripting.
The user interface control tool is software like MOST to operate and change the OTB parameters and testing sequences.
The COSMOS OTB can incorporate different hardware parts that are made available for testing and experimentation. These components can include common sensors, actuators and other hardware systems that are common for satellite integration. Table 1 has an overview of these components.</p>

Table 1: OTB Hardware Components


IMUs, Magnetometers, Accelerometers, Gyros, Sun Sensors, Star Sensors, Horizon Sensors, Thermal Sensors, GPS, Cameras


Magnetic Torquers, Reaction Wheels, Momentum Wheels, Thrusters, Motors for reaction systems, Control Momentum Gyros

Test tools

Air Bearing Platform, Sun Simulator, Thermal Vacuum Chamber, Testing Software

Support Tools

Hardware development platforms, Micro Controllers development boards

Other Systems

Battery Systems, Telecom Systems, Motor controllers, Electronic components, Helmholtz Chamber, Sun Panels, PC 104 boards, Solar Panels,

Finally, the OTB is designed to have the following operation features:
• Calibration and testing of hardware components
• Integrate Software tools for hardware simulation
• Subsystem validation & monitoring
• Subsystems interaction & dynamics monitoring
• Pseudo-environment input (available up to a certain degree)
• Anomaly resolution support
• Measurable performance: like pointing, timing, speed, fast, power, etc.
• Remote control of the OTB using scripts
• Near real time testing and simulations
• Mission Training and rehearsals
• Trending and analysis
• System operation rehearsals and simulations with statistical analysis (e.g. Monte Carlo)
• Operability with different standard software development tools and languages: MATLAB, LabView, Phyton, C/C++, and/or other engineering COTS software utility tools.
• Support the development and operational test for different satellites
One important aspect to note is that the OTB is being designed so that it may be remotely operated, allowing people from different remote locations use this same setup to help in their satellite development or mission operations.