G O D D A R D S P A C E F L I G H T C E N T E R Application of Advanced Filtering Techniques to Current Flight Projects and Future Missions Joel J. K. Parker Flight Dynamics Engineer/595

G O D D A R D S P A C E F L I G H T C E N T E R 2 Overview Summarized Task Description – To develop an interface between the GMAT and ODTBX in-house software tools and apply the integrated suite to a navigation study of a real-world flight project Driver / Need – GSFC navigation relies on classical techniques with limited modeling capabilities – To support advanced missions (i.e. interplanetary, small-body), more advanced estimators and dynamics models will be necessary. Benefits – Enable rapid navigation research (i.e. X-Nav) – Show benefits of advanced estimators for real-world flight projects

G O D D A R D S P A C E F L I G H T C E N T E R 3 Task Objective To develop interface between GMAT and ODTBX in- house software tools To assess benefits of advanced navigation techniques for a real-world flight project To assess advanced navigation techniques for future integration into GMAT in operational capacity To improve the modeling capabilities of GMAT to support ODTBX studies

G O D D A R D S P A C E F L I G H T C E N T E R 4 Accomplishments Organized team and initiated spiral development model with one-month cycles Selected OSIRIS-like small-body mission for navigation study Selected GMAT-ODTBX interface approach and requirements, and implemented a small-scale prototype Implemented GMAT socket interface for less-demanding use cases Implemented or improved 9 GMAT modeling features Implemented and tested plugin for GMAT side of interface Implemented and tested ODTBX side of interface Successfully demonstrated interface on study mission Completed all objectives on schedule, within ~7% of budget

G O D D A R D S P A C E F L I G H T C E N T E R 5 Results: Validation Dynamics modeling comparison: GMAT and the Java Astrodynamics Toolkit (JAT)

G O D D A R D S P A C E F L I G H T C E N T E R 6 Results: Sample Mission

G O D D A R D S P A C E F L I G H T C E N T E R 7 Results: Sample Mission Extended Kalman Filter Monte Carlo Results EKF/Square-Root Information Filter Results Comparison

G O D D A R D S P A C E F L I G H T C E N T E R 8 Milestones and Deliverables Fiscal Year Accomplishments – Work Plan (15d after award) – Quad Chart (15d after award) – Quarterly Report (5 Jan) – Mid-Year Report (6 Apr) – GMAT model requirements spec (31 Jan) – GMAT model math spec (28 Feb) – GMAT/ODTBX interface requirements spec (31 Mar) – GMAT/ODTBX integrated builds (30 Sep) – Analysis and recommendations report (30 Sep) Fiscal Year Plan vs. Actual Deviations – GMAT model math spec (28 Feb/31 Mar) Delayed by GMAT team overcommitments

G O D D A R D S P A C E F L I G H T C E N T E R 9 Recommendations Expand interface to fully replace JAT in ODTBX Significant use cases for GMAT toolkit-level access Expand GMAT platform support and build/test automation Increase ease-of-use for GMAT development Explore GMAT as option for GTDS replacement study

G O D D A R D S P A C E F L I G H T C E N T E R 10 Future / Next Steps Provides design baseline for FY12 IRAD: Cross-Platform Toolkit for Mission Analysis and Design Fits into ongoing SCaN-funded Navigation Integrated Toolsuite (NITS) and GTDS Replacement efforts Future goals: – GMAT as a toolkit – Operational use of GMAT as GTDS replacement in FDF – Increased use of ODTBX backed by GMAT core for navigation research – Ability to support/study advanced mission concepts in-house