1. GOES-R Brown Bag Series
GOES-R Series Flight Data System
William (Bill) Anderson
GOES-R Flight Project
Flight Data System Lead
October 29, 2014

2. 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

3. 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

4. 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

5. 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

6. 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.
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

7. 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

8. 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

9. GOES-R Technology – On Board Intellegence
GOES-R utilizes a RAD 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

10. 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.
SpW is versatile, simple, and can support data rates into the hundreds of Mbps.
SpW supports worm hole routing.
October 29, 2014

11. 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

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

13. 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

14. 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

15. 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

16. 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

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

18. 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

19. 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