Use of Field Programmable Gate Array Technology in Future Space Avionics

Fulfilling NASA's new vision for space exploration requires the development of sustainable, flexible and fault tolerant spacecraft control systems. The traditional development paradigm consists of the purchase or fabrication of hardware boards with fixed processor and/or Digital Signal Processing (DSP) components interconnected via a standardized bus system. This is followed by the purchase and/or development of software. This paradigm has several disadvantages for the development of systems to support NASA's new vision. Building a system to be fault tolerant increases the complexity and decreases the performance of included software. Standard bus design and conventional implementation produces natural bottlenecks. Configuring hardware components in systems containing common processors and DSPs is difficult initially and expensive or impossible to change later. The existence of Hardware Description Languages (HDLs), the recent increase in performance, density and radiation tolerance of Field Programmable Gate Arrays (FPGAs), and Intellectual Property (IP) Cores provides the technology for reprogrammable Systems on a Chip (SOC). This technology supports a paradigm better suited for NASA's vision. Hardware and software production are melded for more effective development; they can both evolve together over time. Designers incorporating this technology into future avionics can benefit from its flexibility. Systems can be designed with improved fault isolation and tolerance using hardware instead of software. Also, these designs can be protected from obsolescence problems where maintenance is compromised via component and vendor availability.To investigate the flexibility of this technology, the core of the Central Processing Unit and Input/Output Processor of the Space Shuttle AP101S Computer were prototyped in Verilog HDL and synthesized into an Altera Stratix FPGA

Increasing productivity through Total Reuse Management (TRM)

Total Reuse Management (TRM) is a new concept currently being promoted by the NASA Langley Software Engineering and Ada Lab (SEAL). It uses concepts similar to those promoted in Total Quality Management (TQM). Both technical and management personnel are continually encouraged to think in terms of reuse. Reuse is not something that is aimed for after a product is completed, but rather it is built into the product from inception through development. Lowering software development costs, reducing risk, and increasing code reliability are the more prominent goals of TRM. Procedures and methods used to adopt and apply TRM are described. Reuse is frequently thought of as only being applicable to code. However, reuse can apply to all products and all phases of the software life cycle. These products include management and quality assurance plans, designs, and testing procedures. Specific examples of successfully reused products are given and future goals are discussed

Satellite Capabilities Mapping - Utilizing Small Satellites

The cost and schedule advantages small satellites have over larger legacy systems have been studied, but there has been very little experimentation performed to determine whether small satellites can actually deliver the capabilities of larger spacecraft. To date, a desired operational capability has not been fully realized by a scalable satellite design. Advances in sensor technology have led to significant reductions in size, weight, and power (SWaP) presenting an opportunity to exploit the evolution of space operations by using small satellites to perform specific missions. This paper describes a methodology that maps a specific set of large space vehicle capabilities to CubeSats. The process examines the utility of advanced sensors. Space weather has been identified as an excellent mission area to exploit the potential of small satellites. Advances in micro-electronics have produced sensors with reduced SWaP, making them viable test subjects. Mapping capabilities to a single or constellation of small satellites, could provide solutions and affordable options to the adverse challenges facing space operations. The methodology developed here selects sensor of the National Polar-Orbiting Environmental Satellite System (NPOESS) Space Environmental Sensor Suite (SESS) and maps them to a CubeSat illustrating a small satellite can perform an operational mission

Definition, technology readiness, and development cost of the orbit transfer vehicle engine integrated control and health monitoring system elements

An Integrated Control and Health Monitoring (ICHM) system was conceived for use on a 20 Klb thrust baseline Orbit Transfer Vehicle (OTV) engine. Considered for space used, the ICHM was defined for reusability requirements for an OTV engine service free life of 20 missions, with 100 starts and a total engine operational time of 4 hours. Functions were derived by flowing down requirements from NASA guidelines, previous OTV engine or ICHM documents, and related contracts. The elements of an ICHM were identified and listed, and these elements were described in sufficient detail to allow estimation of their technology readiness levels. These elements were assessed in terms of technology readiness level, and supporting rationale for these assessments presented. The remaining cost for development of a minimal ICHM system to technology readiness level 6 was estimated. The estimates are within an accuracy range of minus/plus 20 percent. The cost estimates cover what is needed to prepare an ICHM system for use on a focussed testbed for an expander cycle engine, excluding support to the actual test firings

Design and Implementation of Wishbone Bus Interface Architecture for SoC Integration USING VHDL ON FPGA

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Additive Manufactured Structures for the 12U Nanosatellite ERNST

One of the emerging technologies in recent years is additive manufacturing. It promises unprecedented design freedom in both modeling and rapid manufacturing. We are reaping the benefits of additive manufacturing for our 12U nanosatellite ERNST by printing the optical bench that supports the spacecraft payloads. We design the structures by using a finite-element numerical approach for optimizing the topology with respect to 1) available design space, 2) payload interfaces, 3) mechanical launch loads, and 4) thermal loads generated by the cryocooler of the MWIR main payload. We cope with the latter by integrating a pyramidal structured radiator surface in the optical bench as a functional element. Making use of the selective laser melting technique, we manufactured the first version of the optical bench for the engineering model of the ERNST spacecraft from AlSi10Mg alloy. Vibrational testing proved the suitability of our multidisciplinary design approach and the production quality. We are currently implementing the next version of the ERNST optical bench including spacecraft design changes and using Scalmalloy®, a material developed for additive manufacturing that provides high tensile strength and low thermal expansion. This marks a next step on the way to the application of additive manufactured components in space

Potential STS Use by Canada

This paper briefly describes some uses of the Space Shuttle and the Space Transportation System by Canada. The CANADARM (Shuttle Remote Manipulator System) has performed well in its early flight tests and should now be considered as a working tool. The possible Canadian uses of Shuttle in the next few years range from biosciences and space plasma investigations using Spacelab facilities, to launch of commercial communications satellites. Some medium- to long-term possibilities will also be discussed including large satellites and space structures

Development of University-Friendly CubeSat Bus and Ground Station Architecture Using Software-Defined Radios

The goal of the research and development presented in this paper is to introduce a CubeSat bus and ground station architecture that is made to be much more approachable to schools and universities. The three main pillars of the effort are low-cost, maintaining flexibility, and lowering the bar of entry. The presented CubeSat bus includes PyCubed board which houses most of the core satellite bus components on a single board. The board can handle main processing, data storage, UHF radio communication, telemetry sensors, and power management. This UHF radio is paired with a software-defined radio (SDR) that serves as the ground station radio. For a faster data rate downlink of payload data, a low-cost SDR (Ettus B205mini) is paired with a RaspberryPi processor. By leveraging the flexibility of SDRs, one SDR at the ground station is agile enough to provide UHF up/downlink for the CubeSat bus comm, as well as receiving S- or X-band payload data downlink. This proposed architecture will enable project teams to rapidly achieve a baseline capability with the satellite bus such that the development schedule and cost can be drastically reduced while providing the students with the full-cycle experience of satellite engineering

The Preliminary Design of a Standardized Spacecraft Bus for Small Tactical Satellites

Current satellite design philosophies concentrate on optimizing and tailoring a particular satellite bus to a specific payload or mission. Today\u27s satellites take a long time to build, checkout, and launch. An alternate approach shifts the design paradigm to one that focuses on access to space, enabling tactical deployment on demand and the capability to put current payload technology into orbit, versus several years by today\u27s standards, by which time the technology is already obsolete. This design study applied systems engineering methods to create a satellite bus architecture that can accommodate a range of remote sensing mission modules. System-level and subsystem-level tradeoffs provided standard components and satellite structures, and an iterative design approach provided candidate designs constructed with those components. A cost and reliability trade study provided initial estimates for satellite performance. Modeling and analysis based upon the Sponsor\u27s objectives converged the designs to an optimum solution. Major products of this study include not only a preliminary satellite design to meet the sponsor\u27s needs, but also a software modeling and analysis tool for satellite design, integration, and test. Finally, the report provides an initial implementation scheme and concept for operations for the tactical support of this satellite system