Improvements in Spacecraft Assembly, Integration and Test
Frontier Technology, Inc (FTI) received a contract award to provide Kirtland AFB with significantl reduction of the cost and time required for the Assembly, Integration, and Test (AI&T) of future MDA Space Systems.
Space Systems are unique in that they are very expensive, low volume procurements, often requiring a significant amount of hand touch labor. Further, they must be mission ready and perform in highly adverse environments. Space systems typically spend a significant amount of resources testing component mission hardware and software, performing assembly and integration of key assemblies and subsystems, and performing subsystem and system level verification and validation testing. This assembly, integration and test (AI&T) process is time consuming, very labor intensive, and represents one of the largest cost and schedule aspects in the procurement of any space program. The AI&T process historically focuses on discrete subsystems, adopting a “building block” approach to assemble and test the payload and spacecraft. This “building block” approach does optimize or look for efficiencies in context of the entire spacecraft AI&T process. In addition, AI&T requires custom Special Test Equipment (STE) that is typically redesigned at each level of the integration process to accommodate higher level test requirements. Similarly, flight software is validated through a long and arduous process through various software and hardware emulation schemes before it is optimized for the flight processors and validated for operational use.
The review of available literature concerning AI&T clearly demonstrates the lack of research or guidance in this area to create system level methodologies, processes, efficiencies or optimization of workflow. With a few exceptions, available information focuses on reporting of test results from past AI&T efforts and occasionally “Lessons Learned”. The focus is on what was done, not on methodologies and processes to plan and execute synergistic AI&T efforts that look beyond the “building blocks” approach to the spacecraft as a whole. In addition, program specific information about US Systems is export controlled due to applicability to space and is not readily available for review by the community. Even the leading systems engineering handbooks overlook the development and execution of the assembly, integration and test process. They focus on development of the design and test requirements for verification and validation.
The Missile Defense Agency seeks to advance the state of the art in the Assembly, Integration and test of Space Systems to reduce the cost and time required to acquire these systems. The focus of this topic is on space-based systems with particular emphasis on space-based optical systems. Special areas of interest in this topic are: AI&T workflow management, test simulation, and improved software integration and test.
The first area of emphasis seeks proposals for tools to implement processes and methodologies to improve the identification of synergistic requirements of assemblies and subsystems based on verification and validation requirements, effective planning of resources (including utilization of special test equipment (STE) and test facilities), effective scheduling of interrelated processes, and overall work flow management to streamline assembly, integration and test processes.
The second area of emphasis seeks proposals for test simulators/stimulators for use during ground test and verification. Proposals in this area should address either (1) developing tools and hardware simulators to support alignment and calibration of optical system far-field line of sight to microradian accuracy and stability, or (2) the development of high fidelity visible / infrared target sources (stimulators). The target sources should radiate in the visible through Long Wavebands. Knowledge of and the ability to control the radiance of these sources in each wavelength band is critical.
The third area of emphasis seeks proposals for improve software integration and test tools and methods. These tools should support simulation-based testing at the various stages of development including design, embedded software development, prototype integration, full system integration testing, and training. The proposed architectures should support pure simulation, software-in-the-loop simulation, man-in-the-loop simulation, and hardware-in-the-loop simulation allowing for maximum reuse of payload simulation and testing assets in all modes of operation. To facilitate a scalable and efficient integration testing process, the system should enable simulation-based test projects to be executed in non-real-time on a general purpose operating system (GPOS) based platform for low-cost test development, verification and validation; and in real-time on a real-time operating system (RTOS) based computer platform for hardware-in-the-loop and man-in-the-loop testing. To assist with obsolescence avoidance, the payload simulator architecture should leverage an open-source RTOS, where possible.