FGPA Design and Testing Suite for Spacecube 3.0

The SpaceCube 3.0 Mini Processor Card represents orders of magnitude increase in performance and capability over typical radiation-hardened processor-based systems and significant advances over the previous generation of SpaceCube technology. The primary processing engine of the card is a radiation-tolerant FPGA. This processor card is very low weight, can fit within the 1U CubeSat form-factor (10cm x 10cm x 10cm), and will be low power. Much of the SpaceCube 2.0 Micro design is incorporated into the SpaceCube 3.0 Mini design. In addition, lessons learned from the SpaceCube 2.0 Mini card are applied. Instead of using a rigid-flex design, the SC3.0 Mini uses a backplane architecture. The processor card plugs into a backplane that routes signals to other card slots. In order to meet the numerous high-speed I/O interfaces required by the latest generation science instruments and applications, a high-density backplane connector is needed. The SpaceCube 3.0 Mini uses a high-density connector to plug into the backplane. The FPGA has flash memory attached that is used for storing algorithm and application code for any hosted soft processors. The processor card also has a nanominiature front-panel connector that adds even more I/O to support instrument interfaces such as Camera Link or SpaceWire. The SpaceCube 3.0 Mini Processor Card features a rad-tolerant FPGA, but the radiation mitigation can be tailored for harsher environments by adding an external rad-hard device that configures and monitors the FPGA over the backplane. The processor card pushes transceiver quantity, routing, and performance for spaceflight. The card is designed to fit in the compact 1U CubeSat form factor. The SpaceCube 3.0 Mini supports scalability by networking multiple processor cards together.

SpaceCube 3.0 features the rad-tolerant multi-core T2080 processor and the rad-tolerant Kintex UltraScale FPGA. The SpaceCube 3.0 Flight Processor Card meets the industry standards in lightweight systems specifications. In addition, the flight processor card can be installed with an expansion card option to allow a tightly-coupled, mission unique card to be installed. The mission unique expansion card can support a variety of capabilities to make SpaceCube 3.0 a powerful instrument processor, including A/D converters, D/A converters, gigabit ethernet, and additional co-processors. Furthermore, the flight processor card is extremely flexible. Algorithms can be implemented in both the Kintex UltraScale FPGA and the T2080 processor. More sequential portions of the algorithm can be implemented quickly and efficiently on the processor, while other algorithms that are more parallel in nature and computation heavy can be accelerated in the FPGA. Using a hybrid system, each can be optimally implemented to take advantage of the features of both. The SpaceCube 3.0 Flight Processor Card design consists mostly of NASA-qualified flight parts and has many features to mitigate radiation effects on the processor system. The processor card can configure the FPGA to scrub configuration memory. In addition, it can monitor the health of the processors, the FPGA, and any coprocessors on the expansion card using watchdog timers. The FPGA uses error detection and multiple redundant copies to mitigate against radiation upsets to the configuration files, which are stored in external non-volatile memories.

This dual band infrared imaging system is capable of spatial resolution of 60 m from orbit and earth observing expected NEDT less than 0.2o C. It is designed to fit within the top two-thirds of a 3U CubeSat envelope, installed on the International Space Station, or deployed on other orbiting or airborne platforms. This infrared imaging system will utilize a newly conceived strained-layer superlattice GaSb/InAs broadband detector array cooled to 60 K by a miniature mechanical cryocooler. The camera is controlled by a sensor chip assembly consisting of a newly developed 25 m pitch, 640 x 512 pixel.

Next generation instruments are capable of producing data at rates of 108 to 1011 bits per second, and both their instrument designs and mission operations concepts are severely constrained by data rate/volume. SpaceCube is an enabling technology for these next generation missions. SpaceCube has demonstrated enabling capabilities in Earth Science, Planetary, Satellite Servicing, Astrophysics and Heliophysics prototype applications such as on-board product generation, intelligent data volume reduction, autonomous docking/landing, direct broadcast products, and data driven processing with the ability to autonomously detect and react to events. SpaceCube systems are currently being developed and proposed for platforms from small CubeSats to larger scale experiments on the ISS and standalone free-flyer missions, and are an ideal fit for cost constrained next generation applications due to the tremendous flexibility (both functional and interface compatibility) provided by the SpaceCube system.

The system includes a fundamental local oscillator (LO) source composed of a broad-band tunable frequency synthesizer as well as a crystal oscillator. The synthesizer employs a harmonic doubler to expand frequency coverage. The CubeRRT system uses a series of RF switches and band-pass filters, to select the desired harmonic while suppressing unwanted harmonics. The CubeRRT system uniquely combines several technologies to minimize the number of frequency banks and thus reduce mass, volume and power requirements. The CubeRRT system uses four frequency banks in order to provide continuous microwave receiver coverage from 6GHz to 40GHz.