1 1 Briefing for AIAA SOSTC Workshop April 2011 Tobias Nassif, Director SDA

2 2 What is the Space Data Association?  A formal association of satellite operators, established in the Isle of Man which will support the controlled, reliable and efficient sharing of data critical to the safety and integrity of satellite operations –Legal framework to protect the sharing of data –Physical systems to make data sharing efficient, secure and reliable reducing operators workload and mitigating risks –Technical support to ensure operations integrity –Shared costs and ‘not-for-profit’ ethos to reduce individual costs

3 3 SDA Charter  Seek and facilitate improvements in the safety and integrity of satellite operations through wider and improved coordination between satellite operators  Seek and facilitate improved management of the shared resources of the Space Environment and the RF Spectrum

4 4 Why was the SDA created?  To improve the accuracy of collision avoidance predictions –Expand satellite operator participation –Adopt best practices across industry –Provide necessary framework for full operations (legal, technical) –Address operational issues with current cross-industry conjunction coordination  To take advantage of opportunities for other data sharing –RFI mitigation, including data for RFI geolocation –Company contacts –General operations data sharing

5 5 Growth of Objects in Space

6 6 Who can join the SDA?  The SDA will be run by and for the benefit of satellite operators and the integrity of their operations –Members should be the owners or responsible for the control and orbit operations of in-orbit satellites –Membership is open to all satellite operators in all orbital regimes

7 7 Why Join the SDA?  Members will receive secure, reliable and immediate access to accurate information that can help improve their operations –Conjunction assessments –Data for RF Interference analysis and geolocation –Contact information  Ensure the following of best practices and mitigating operational risks  Reduce workload –Automated data conversions for conjunction –Information readily available –Focus on real issues identified by reliable systems  Ensure the use of shared data is controlled and legally protected  Minimize the cost for these critical operations SDA membership will improve the integrity of its members’ satellite operations and that of all satellite operators

8 8 SDC – Three Key Mission Areas Collision Avoidance (CA) monitoring, maneuver planning & Flight Safety Radio Frequency Interference mitigation & geolocation support Authoritative contact information (operations center & POCs) for SDA Member satellites Initial Operating Capability (IOC) commenced 27 July 2010 Final Operational Capability (FOC) expected Q SDC currently performing Collision Avoidance monitoring for 197 satellites from 13 GEO operators and 114 satellites from 7 LEO operators

9 9 Key Components of a Reliable and Robust SDC Providing Meaningful Space Situational Awareness (SSA): Clear, comprehensive key SSA mission areaskey SSA mission areasScreening every two hours for one-week duration Definitive ephemeris, maneuvers & physical properties Accurate data rectification and Ephemeris Quality Control Process Definitive SDA Member RF characteristics (geolocation, ASI)SDA Member RF characteristics Integrated, automated CA And RFI using all- inclusive, latest data from best-available sourcesCARFI Centralized, authoritative POC databaseData TrendingData Trending for CA & RFI Repeat Offender ID & SSA ResearchRepeat Offender Addresses known Non-Cooperative Tracking (NCT) shortcomings (e.g., no powered flight, maneuver corruption of orbit solution, cross-tagging)maneuver corruption of orbit solutioncross-tagging Comprehensive RFI mitigation capabilitiesComprehensive RFI mitigation capabilities (RFI geolocation support, RFI analyses and near-real- time RFI alerts) Operated by Technical Subject Matter Experts (CA & RFI, Reference Frames, OD, Space Population Evolution & Distribution, Fragmentation, Maneuver Reconstruction & Detection, Astrodynamics, Ephemeris Rqmts For Accurate SSA)Technical Subject Matter ExpertsCA RFIReference FramesOD Evolution DistributionFragmentationManeuver Reconstruction Ephemeris Rqmts For Accurate SSA Relies upon ISO, CCSDS Intl Stds & Best Practices (Orbit Data Messages, Reference Frames, Orbit Determination and Orbit Lifetime)Orbit Data MessagesReference FramesOrbit DeterminationOrbit Lifetime SDC Database-Driven Analysis Framework SDC Database-Driven Analysis Framework Supporting both Web Services interfaces + Accessible User Interface Accessible User Interface Geographically-diverse, secure, high-availability computing framework with extensive data protectionextensive data protection

10 SDA’s Role in Industry Issues Operational Challenges Causes Typical Mitigation Approach SDA’s role in Addressing Ops Challenges Mitigating Collision Risk -Space is increasingly congestedSpace is increasingly congested -ITU doesn’t regulate physical space -No integrated CA screening with all best- available data Services such as: -Socrates-GEO -Non-Cooperative Tracking agencies (NCTs) -Commercial collision avoidance services SDA Conjunction Assessment Service Mitigating RF Interference RFI Increasing; Sources: -Human error (95%) -ASI -Cross-pol / Pwr issues -Terrestrial Rx Issues (1%) -Equipment fault (4%) -Deliberate (tiny %) Operator actions such as: -Signal analysis -Carrier record checks -Customer checks -Alerts to other operators -Predictive RFI analyses (GEO drifters, LEO) -Geolocation (if available) SDA RFI Service and Alerts

11 SDC Planned CA Process Flow Members contribute and dynamically maintain proprietary satellite maneuver plans, dimensions, status Members define vehicle-specific conjunction and Neighborhood Watch criteria Satellite ephemerides are automatically updated by all SDA members Non-Cooperative Radar and Optical Tracker-based orbit vectors and/or ephemeris Close Approach Alert notification sent to Members Optional information accumulated for collision threat trending and long-term threat mitigation Rectified data and STK analysis scenarios facilitate maneuver avoidance planning & optimization Data provided on upcoming conjunctions, and contact information to conduct collision threat mitigation SDC Data stored in common format System allows faster investigation of CA events, enabling responsive and accurate threat mitigation Independent SDC vector comparison & OD verification SDA Member-unique ephemeris converter created & tested Conjunctions Analyzed Conjunctions Alerts Sent Neighborhood Watch Results Sent

12 SDC Planned RFI Process Flow Members contribute and dynamically maintain proprietary RF data: Freq plan; polarization; translation freqs; antenna patterns, Rx & Tx chars, beam coverage Members contribute data on Reference Emitters/Calibrators Satellite ephemerides are automatically updated by all SDA members Members detect an RFI event and report the details to the SDC RFI Alert notification sent to Members Optional information provided to third parties for geolocation or other services Geolocation solution sets generated and sent to Member in format for geolocation system Database queried for most likely region, satellite(s), and contact information to investigate potential interference source SDC Frequency bands and beam coverages searched for suitable adjacent satellites for geolocation measurements Data stored in common format System allows faster investigation of RFI events, improving service quality and creating more efficient operations

13 SDA and Geolocation  Without SDA –Multiple phone calls required –Hours/days required to locate viable solution set and data –Data formats = anyone’s guess  With SDA –Solution sets immediately available –All necessary data centralized and in consistent format –Better data = more accurate results  Geolocation error reduced two orders of magnitude using SDA-on-SDA quality ephemeris SDA enables faster, more accurate geolocation results

14 RFI Geolocation Sample Case

15 RFI Geolocation Sample Case

16 Potential Future SDA RFI Capabilities  Collect, process, store & disseminate interference details, analyses & solution sets from all sources to enable appropriate investigation, notification and enforcement –both within SDA and with approved external entities  Coordinate data with and for SDA RF experts to identify, analyze, locate, attribute and mitigate interference sources  Develop & maintain RFI mitigation capabilities, procedures and techniques to ensure continuity of operations

17 Space Population Perigee-vs- Apogee Distribution

18 Space Population and Risk  Spatial density of space objects at GEO higher than at LEO –“Constrained” GEO inclination = contributing factor –Statistics less of interest than actual collision threats!

19 Why Non-Cooperative Tracking (NCT) is not enough…  Radar & optical tracking good for debris data but may have errors for active satellites  NCTs fit orbit across maneuver(s) –Low thrust, long duration burns common at GEO –Degrades OD sol’n accuracy regardless of orbit theory  “Cross-tagging” –Observations associated with wrong satellite  i.e., multiple satellites in sensor field of view  “Cross-tagging most likely when you need most accuracy”  Caused / compounded by maneuvers during tracking –NCT obs. association independent of OD/theory

20 Cross-tagging and System Errors  Galaxy-15 anomaly caused westward drift with no maneuvers from April – December 2010 –G15 WAAS intact; orbital position well understood by operator but not in public catalog –Great opportunity to study public data-derived performance  Large cross-tag discontinuity observed 13 Aug –Readily identified as G15/G18 conjunction  Many other such discontinuities observed  Collision risk was never an issue because SDA Members were sharing ephemerides with the SDC

21 Semi-Major Axis Reveals NCT Discontinuities…

22 “TLE Detective” Identifies Cross-tags For G15 case, using 2.5σ filter with recursive excision, found that 52 out of 348 (15%) of NCT- derived positional products contain cross-tag or equivalent accuracy degradations

23 Discontinuities Match Conjunctions…

24 Crosstags Reduce NCT GEO Accuracy  Example: G-15 drifting, no maneuvers, known position –Errors caused by NCT method & non-optimal scheduling  Not caused by bad analysts or bad hardware –Can degrade solution for all involved satellites during flyby 15% of Galaxy-15 NCT positions are cross-tags or equivalent and are most likely when you need most accuracy

25 The Next Steps The SDC has commenced initial operations Final Operational Capability scheduled Q The SDA is promoting its services and encouraging all satellite operators to become Members Members can become involved with future requirements, development and testing of the CA and RFI functionality The SDC is expected to evolve and become a major operational system for satellite operators, for safety of flight, and RFI mitigation

26 Additional NCT Cross-tagging IS-6BIS-3RIS-11 IS-6BIS-3RIS-11 Owner ephemerides Public Data 43.25° W 43.00° W 42.75° W Spacing = 184 km 2008 Comparison