GOES-R Brown Bag Series GOES-R Series Flight Data System William (Bill) Anderson GOES-R Flight Project Flight Data System Lead William.H.Anderson@nasa.gov 301-286-7569 October 29, 2014

GOES-R Flight Data System Agenda What’s new/different from a data management perspective. In The Beginning Where We Are Today Technology developed for GOES-R series spacecraft. EDAC On Board Intelligence SpaceWire Reliable Data Delivery GOES-R data sources and sinks. C&DH Architecture October 29, 2014

GOES-R What’s New/Different – In The Begining Earlier GOES spacecraft utilized deterministic Time Division Multiplexing (TDM). On board data was “commutated” into a structure known as a frame. When a frame is received on the ground, a “decommutation” process is applied to recover individual measurands. Bit slips and bit errors can cause data loss. October 29, 2014

GOES-R What’s New/Different – Where We Are Today The following is an excerpt from the Wikipedia entry on GOES-R: GOES-R will mark the first major technological advances in geostationary observations since 1994. Compared to the current GOES system, the advanced instruments and data processing will provide: Three times more spectral information Four times greater spatial resolution Five times faster coverage Real-time mapping of total lightning activity Increased thunderstorm and tornado warning lead time Improved hurricane track and intensity forecasts Improved monitoring of solar x-ray flux Improved monitoring of solar flares and coronal mass ejections Improved geomagnetic storm forecasting  These improved capabilities presented a unique set of challenges for the design of the GOES-R flight data system. October 29, 2014

GOES-R What’s New/Different – Where We Are Today GOES-R is a packet telemetry and packet telecommand system. Packets are non-deterministic data structures. System buffering and through put allow packets to be sent when ready with minimal wait times. Packet transmission components are independent and isolated from the data in the packet. Everything required to recover measurands is contained in the packet header. Packet types and contents can be modified on orbit. October 29, 2014

GOES-R What’s New/Different – Where We Are Today GOES-R complies with Consultative Committee for Space Data Systems (CCSDS) telemetry and telecommand recommendations. http://public.ccsds.org/default.aspx From CCSDS Web site: “eleven member agencies (world wide), twenty-eight observer agencies, and over 140 industrial associates” “--- actively developing recommendations for data and information systems standards to promote interoperability and cross support among cooperating space agencies” Building GOES-R to data standards helps reduce costs. COTS products available – don’t have to reinvent the wheel October 29, 2014

GOES-R What’s New/Different – Where We Are Today Source Packet format - a frame is a frame is a frame --- The APID is used to route and process the data contained in the packet Used for both telemetry and command The GOES-R high level packet format is defined in the GIRD Lower level packet formats are defined in the instrument and spacecraft CMD/TLM handbooks. APPLICATION PROCESS ID 11 bits October 29, 2014

GOES-R Technology– Error Detection and Correction Improved data reliability – multiple layers. GOES-R uses multiple Error Detection and Correction (EDAC) through out the data system to have highly reliable data delivery to the ground. Packets can contain EDAC codes to reduce errors and data loss. Transmission systems utilize protocols to improve reliability. Space-to-ground links use coding to improve margins and reduce data loss. October 29, 2014

GOES-R Technology – On Board Intellegence GOES-R utilizes a RAD750 32 bit computer with Wind River’s VxWorks operating system (MacIntosh in the sky). The instruments are also intelligent. Flight software is written in C with some minor exceptions. ABI - RAD750 with VxWorks SUVI - RAD750 with VxWorks SEISS - Atmel TSC695FL EXIS - RTAX2000 Actel Core8051 GLM - BAE ASIC Embedded Microcontroller (EMC) October 29, 2014

GOES-R Technology – SpaceWire SpaceWire (ECSS-E50-12A) is a standard for high-speed links and networks for use onboard spacecraft, easing the interconnection of: sensors mass-memories processing units, and downlink telemetry sub-systems. http://www.spacewire.esa.int/content/Home/HomeIntro.php SpW is versatile, simple, and can support data rates into the hundreds of Mbps. SpW supports worm hole routing. October 29, 2014

GOES-R Technology – SpaceWire NASA and GOES-R participated in the development of the BAE SpW Application Specific Integrated Circuit (ASIC). OCB Connection Medium EMC 64 OCB Master OCB Slave SRAM PID’s MISC 32 Existing New/Modified UART MCTL Memory I/F JTAG JTAG Slave (JTAG) Clocks/Reset CAT PLL RIF External I/F EXTIF 1 EXTIF 2 Spacewire Router and Links Spacewire I/F 4 FIFO October 29, 2014

GOES-R Technology – SpaceWire GOES-R indirectly participated in the development of the Aeroflex 4 port SpW router ASIC. October 29, 2014

GOES-R Technology – SpaceWire GOES-R developed an in house proof of concept SpaceWire system. This system consisted of 6 Windows based work stations and custom SpW test cards BAE ASIC test card: October 29, 2014

GOES-R Technology – SpaceWire GOES-R developed an in house proof of concept SpaceWire system. FPGA based SpW Test Set (SWTS) card: October 29, 2014

GOES-R Technology – Reliable Data Delivery SpW (physical layer) provides a limited error management capability. GOES-R Flight System Engineering levied requirements for higher level error management for the SpW links. In response, the GOES-R Reliable Data Delivery Protocol (GRDDP) was developed by the C&DH team. GRDDP was presented to and accepted by the SpW working group (PID 238). All instrument to spacecraft communications requires use of the GRDDP. October 29, 2014

GOES-R Technology – Reliable Data Delivery GRDDP was designed to have minimum impact on flight computers. GRDDP sample software is ~700 lines of C code. GRDDP sample code has been provided to a number The GOES-R GRDDP sample code was provided to all GOES-R contractors. GRDDP sample code has been provided to a number of non NASA/NOAA programs. SEISS and EXIS have implemented the GRDDP in FPGAs. October 29, 2014

GOES-R Data Sources and Sinks – C&DH Architecture C&DH Block Diagram October 29, 2014

GOES-R Data Sources and Sinks – C&DH Architecture C&DH Block Diagram - OBC RAD750 hosts Flight Software 8 SpaceWire Nodes provides Interfaces to Instruments MIL-STD-1553B Bus Controller to Spacecraft Components CCSDS Formatting and LDPC encoding to Raw Data Link for Instrument Data 1PPS Generation and Distribution IMU Interface GPSR Interface Maintains Spacecraft Clock Internally Redundant October 29, 2014

GOES-R Data Sources and Sinks – C&DH Architecture C&DH Block Diagram - CTP Interface to CDAS and ORTT&C Comm Equipment Command receptive on all Communication Uplinks Performs CCSDS Validation of all uplinked commands including COP-1 protocols Interface to the Command Decryption Unit Assembly CCSDS Formatting and Reed Solomon encoding to CDAS and ORTT&C Equipment Execution of Hardware Commands -32V Relay Drive Commands +28V Pulse and Level Commands Monitors Health and Controls the state of the OBC Internally Redundant October 29, 2014