1. 1 The PISCES Project Don J. Pearson JSC/DM Flight Design & Dynamics Division May 2002 don.j.pearson@jsc.nasa.gov

2. p2 PISCES Platform Independent Software Components for the Exploration of Space u Orbtial Mission Design and Analysis Components –orbital propagation, basic trajectory components (library) for orbital trajectories around Earth, the Moon, and Mars. –Graphical input, visualized outputs –Focus on Agency-wide (Program independent) Rendezvous capability

3. p3 Technology Objectives u PISCES originated as an RTOP with 3 technology objectives: –Re-establish civil service expertise in human missions beyond LEO (Agency and Center emphasis) with a focus on Rendezvous –Evaluate potential of a Java-based object-oriented mission planning system »web-based, distributed planning environment »platform independence »national interest in the use of Java for Science and Engineering –Develop tools via partnerships with universities rather than traditional aerospace contract »economic decision / objective of project »HEDS strategic initiative “bring space exploration experience into the classroom... new initiatives to inspire students to study science, math...”

4. p4 PISCES Components u Developed precision orbital propagation software (100% completely re-engineered) –Reusable utilities: »Vector/Matrix math, iterators »Time (JulianDate) –Astronomical Body models »physical models, lunar/planetary coordinate systems »extremely high fidelity gravity models (e.g.: 75x75 Moon, 50x50 Mars), atmosphere models, solar radiation models –Spacecraft models »transitioning from point mass vehicles with impulsive burns to vehicles with thrusters, attitude profiles, etc »precision integration models to move spacecraft through environment –Rendezvous: »Launch window: when/how to get off the planet »Rendezvous Maneuver Targeting: how to chase down the satellite –Graphical: »3D visualization: “immersive environment”

5. p5 PISCES Applications u Rendezvous design and real-time operations –Target spacecraft onorbit (initial vector or ephemeris if maneuverable) –Launch Window / Launch Targeting »computes lift-off time, launch window, ascent cutoff state »launch time and targeting depends on rendezvous strategy (phase wraps,etc) –Orbit Maneuver Application (OMA) »generic maneuver planning »maneuvers scheduled based on time, DT, apsis conditions, orbital lighting, ground passes, etc. »mix of u phasing, height adjustments (targeted to various downrange,altitude conditions) u planar maneuvers u circularization, coelliptic maneuvers u Lambert maneuvers –Relative motion plots u Validated on current Shuttle missions via streaming telemetry

6. p6 Rendezvous Planning

7. p7 Rendezvous Solutions

8. p8 Interactive 3D Visualization

9. p9 Interactive 3D visualization

10. p10 Planetary Rendezvous Capability

11. p11 Leap in State-of-Art Rendezvous Planning u Maneuver Planning Functionality Improvements : –J2K, Metric »M50, English units –Modular, plug-N-play propagation schemes (detailed gravity, atmosphere models, solar radiation modeling, N-body gravity, attitude profiles, variable mass) »hardwired to analytic propagation techniques limited to 4x2 gravity »limited to Jacchia-Lineberry atmosphere, sampled ~6 times per orbit »no solar radiation or N-body effects »constant CD, area, mass (only adjusted for maneuver delta-v) –Additional maneuver scheduling capabilities eliminating manual iterations »relative apsis, ground passes –Java »Fortran, 6 character variables, large common blocks for data transfer »30 years of patching, Limited to LEO

12. p12 Unique Architecture Features u PISCES is (and our current operational mission planning software packages aren’t) : –platform independent »portability concerns are minimized »reduced maintenance costs –distributed »client applications support multiple users »reallocation of client/server responsibilities easy –web-based »programs architected to be run via the Internet u software maintained at JSC and used by clients across Agency u note: architected, but not currently in use via the Internet –multi-threaded »can run multiple processes simultaneously u eg: running multiple Kalman filters, targeting scenarios –enticing to today’s emerging software professionals

13. p13 Summary u PISCES strategically positioned to become a “tool of choice” for Agency-wide rendezvous mission design and analysis –Architected for portability, expandability, maintainability –Functional for LEO, HEO, planetary rendezvous –Expandable component library