Texas A&m Engineering Experiment Station

Who it subcontracts to

No subawards reported under its lunar awards.

Who it works for

1. The Regents of the University of Colorado$644K

   THIS PROPOSAL WILL CONTINUE AND EXPAND THE RESEARCH INITIATED IN THE CURRENT AFOSR GRANT WITH AFOSR. TEXAS A&M/TEES PROPOSES RESEARCH IN THE FOLLOWING AREAS. THE RESEARCH MAY NOT BE LIMITED TO THESE AREAS. TRACK ASSOCIATION IN CISLUNAR SPACE WE WILL EXTEND THE RESEARCH COMPLETED IN THE CURRENT GRANT TO CISLUNAR SPACE. THE MEAN MODIFIED EQUINOCTIAL ELEMENTS RESULTED IN ALMOST LINEAR DIFFERENTIAL EQUATIONS THAT WERE VALID FOR MANY ORBITS. NO KNOWN EQUIVALENT APPROACH EXISTS IN CISLUNAR SPACE. NEW APPROACHES FOR PROPAGATING THE SYSTEM UNCERTAINTY WILL BE NECESSARY. AREAS OF RESEARCH WILL INCLUDE GAUSSIAN SUMS AND MONTE CARLO. RELATIVE MOTION IN CISLUNAR SPACE SATELLITE FORMATIONS AND STATIONKEEPING REQUIRE DESCRIPTION OF THE RELATIVE MOTION OF SPACE OBJECTS. FOR OBJECTS IN EARTH OBJECT THIS RELATIVELY STRAIGHTFORWARD WHEN USING DIFFERENTIAL ORBITAL ELEMENTS EVEN WHEN INCLUDING GRAVITATIONAL PERTURBATIONS. AS WITH TRACK ASSOCIATION THE DYNAMICAL ENVIRONMENT IN THE CISLUNAR ENVIRONMENT IS DIFFERENT AND THERE IS NO ANALOG TO THE ORBITAL ELEMENTS THAT LEAD TO A NICE SET OF LINEAR DIFFERENTIAL EQUATIONS. THE OBJECTIVE HERE WILL BE TO DETERMINE OPTIONS FOR DESCRIBING THE RELATIVE MOTION OF SPACE OBJECTS. LUNAR ANALYTIC ORBIT THEORY FOR MOTION NEAR THE MOON UNDER THE CURRENT GRANT WE HAVE DEVELOPED AN ANALYTIC ORBIT THEORY FOR THE NON-SPHERICAL GRAVITATIONAL PERTURBATIONS. WORK HAS BEGUN ON EXTENDING THIS THEORY BY ADDING THE 3RD BODY PERTURBATIONS. WE PLAN TO CONTINUE THIS WORK TO DEVELOP THIS NEW THEORY AND ITS USE IN FINDING SPECIAL TYPES OF ORBITS LIKE LUNAR FROZEN ORBITS. IT MAY ALSO BE A GOOD APPROACH FOR RELATIVE MOTION OF ORBITS ABOUT THE MOON. A KEY PART OF THIS PROGRAM WILL BE COLLABORATION BETWEEN THE UNIVERSITY OF COLORADO AND TEXAS A&M UNIVERSITY ON RESEARCH PROJECTS AND ADVISING GRADUATE STUDENTS. THIS PROPOSAL CONTINUES THE RESEARCH DR. SCHEERES OF THE UNIVERSITY OF COLORADO AND I HAVE PERFORMED OVER THE PAST NINE YEARS WITH AFOSR. THIS RESEARCH FOCUSED ON PRESSING PROBLEMS IN SPACE DOMAIN AWARENESS (SDA) ABOUT THE EARTH. THIS PROPOSED RESEARCH WILL EXPAND PREVIOUS WORK AND FOCUS ON SDA IN CISLUNAR SPACE. CISLUNAR SPACE IS MORE DYNAMICALLY CHALLENGING BECAUSE OF THE EFFECTS OF THE EARTH AND SUN. IN MUCH OF CISLUNAR SPACE THE DYNAMICAL SYSTEM WILL BE THE RESTRICTED THREE BODY PROBLEM. EVEN THOUGH THE DYNAMICAL ENVIRONMENT IS MORE CHALLENGING MANY OF THE SAME PROBLEMS EXIST, INCLUDING, BUT NOT LIMITED TO ASSOCIATING TRACKS TO OBTAIN INITIAL ORBITS OF SPACE OBJECTS, MANEUVER DETECTION, CHANGE DETECTION, SENSOR SCHEDULING. ALONG WITH THE UNIVERSITY OF COLORADO TEXAS A&M WILL PERFORM RESEARCH IN THESE AREAS.

2. University of Texas at Austin$455K

   REPRESENTATIONS, THEORY, AND ALGORITHMS FOR AUTONOMOUS SPACE DOMAIN AWARENESS IN THE CISLUNAR REGIME

3. Ohio State University$449K

   THERE ARE TWO GOALS OF THIS PROJECT: 1. TRANSFORM THE MODELING OF ORBITAL MECHANICS BY AUGMENTING PHYSICS-BASED DYNAMICS WITH EXPLAINABLE DATA-DRIVEN TECHNIQUES. THE RESULTING PHYSICS/DATA “HYBRID MODELS” WILL BE INTEGRATED WITH THE FOLLOWING APPLICATIONS: (A) KEY FUNCTIONS IN THE SPACE-DOMAIN AWARENESS (SDA) KILL CHAIN (FIG.(1)), INCLUDING DETECTION, INITIAL ORBIT DETERMINATION AND ORBIT DETERMINATION, DATA-ASSOCIATION, MAINTAINING OBJECT CUSTODY, AND INTENT ESTIMATION. (B) HIGH FIDELITY MODEL DEVELOPMENT FOR THE XGEO AND CISLUNAR DOMAINS TO ADDRESS THE DUAL CHALLENGE OF HIGH NONLINEARITY AND LONG PROPAGATION TIMES IN THESE REGIMES. 2. EXTEND THE OUTCOMES OF DATA-AUGMENTED MODELING IN ORBIT TO ANSWER FUNDAMENTAL QUESTIONS RELATED TO THE THEORY OF NONLINEAR SYSTEM IDENTIFICATION. FIGURE

4. Rensselaer Polytechnic Institute$75K

   RT1: PI SINGH WILL LEAD THE STUDIES PERTAINING TO THE DEVELOPMENT OF EFFICIENT MATHEMATICAL MODELS OUTLINED IN RT1. CO-PI MAJJI WILL DEVELOP HIGH ORDER STATE TRANSITION TENSORS (STTS) FOR THE SATELLITE RELATIVE MOTION IN THE CISLUNAR SPACE TO SERVE AS A BASELINE FOR THE REDUCED ORDER MODELS DEVELOPED BY PI SINGH. RT2: PI SINGH WILL LEAD THE PARAMETERIZATION OF THE CISLUNAR RSO TRAJECTORIES AND THEIR ADJOINTS (FOR OPTIMAL CONTROL AND REACHABILITY ANALYSIS) REQUIRED FOR CONSTELLATION DESIGN AND RECONFIGURATION. CO-PI JUNKINS WILL DEVELOP EXTREMAL FIELD MAPS FOR OPTIMAL CISLUNAR TRANSPORT AND REACHABILITY ANALYSIS TO EVALUATE THE IMPLEMENTATION COSTS OF THE NEW METHODS DEVELOPED BY PI SINGH. RT3: PI SINGH WILL WORK CLOSELY WITH CO-PI MAJJI TO DEVELOP ROBUST MULTI-SENSOR INFORMATION FUSION TECHNIQUES TO TRACK MANEUVERING RSOS. THEY WILL LEVERAGE PRIOR SPACE DOMAIN AWARENESS EXPERIENCE AND IMPLEMENTATION EXPERIENCE OF CO-PI MAJJI TO DEVELOP KEY TOOLS FOR RSO TRACKING FOR A GIVEN SENSOR CONFIGURATION. RT4 AND 5: PI SINGH AND CO-PI MAJJI WILL COMPLETE THE ROBUST MUTI-SENSOR INFORMATION FUSION TECHNIQUES FOR EACH POSSIBLE PARAMETER VALUE THAT GOVERNS THE CONSTELLATION/FORMATION CONFIGURATION. THEY WILL THEN STUDY THE CONSTELLATION RECONFIGURATION PROBLEM AND DEVELOP METHODS TO IMPLEMENT THE SENSOR MANAGEMENT APPROACH TO ADAPT THE SENSORS INVOLVED. RT6: CO-PIS MAJJI AND JUNKINS WILL FORMULATE A SET OF CHALLENGE PROBLEMS TO RECONFIGURE SENSOR SATELLITES FLYING IN A CONSTELLATION TO TRACK A MANEUVERING RSO IN CISLUNAR SPACE. PI SINGH WILL APPLY THE TECHNIQUES DEVELOPED IN THIS RESEARCH TO EVALUATE THEIR EFFICACY TO SOLVE THE CHALLENGE PROBLEMS. THE TEAM WILL PUBLISH THE CHALLENGE PROBLEMS TO THE SCHOLARLY COMMUNITY AND WORK TO COMPILE A JOURNAL SPECIAL ISSUE CONSISTING OF ALL SOLUTION TECHNIQUES AND CORRESPONDING PERFORMANCE MEASURES ASSOCIATED WITH THE INTERESTING SOLUTION APPROACHES PROVIDED BY THE SCHOLARLY COMMUNITY