AFRL PNT S&T Investments

Transcription

1 AFRL PNT S&T Investments 12 November 2015 Integrity «Service «Excellence Colonel David Goldstein Air Force Research Laboratory Space Vehicles Directorate OPS

2 Overview What We Value Naviga1on Technology Satellite (NTS) 3 ANGELS Small Satellites C/NOFS DSX 2

3 What We Value Our Core Values S&T excellence Boundary pushing Professional competency and contribu1on Mission focus External Advancing state- of- the- art Visionary and innova1ve S&T Resiliency Partnerships toward synergis1c investments Skin in the game All of you! 3

4 Navigation Technology Satellites (NTS) NTS-1 (Launched: 1974) Timation and 621B programs merged to become NAVSTAR GPS program. NRL'S Timation 3 satellite re-designated the NTS-1 Two rubidium-vapor frequency standards (clocks) NTS-2 (Launched: 1977) 1st NAVSTAR GPS Phase I satellite Cesium frequency standards (clock) Nickel-hydrogen battery Worldwide network for data acquisition Verified Einstein's relativistic clock shift NTS-2 NTS-1

5 NTS-3 is AFRL s Next Flight Experiment Objectives Advance state-of-the-art satellite hardware and software High gain antennas High Power Amplifiers Flexible digital payload Atomic Clocks Explore new operations concepts Know ephemeris though active control Alternate TT&C and ground Hosted payload Conduct wide variety of science experiments Integrated space, ground and cyber Examples: relativity experiments, advanced signals, active maneuver with precise OD, tactical TT&C, localized signals DISTRIBUTION A. Approved for public release: distribu=on unlim

6 Military High Gain Antenna Options 1) Deployable phased array Low profile element High efficiency phase shifters at each element Leverages legacy payload amplifier and diplexer Heritage deployment mechanism 2) Electronically steerable Earth deck array Features construction modularity and high efficiency Minimum S/V mass impact Eliminates triplexer and high gain amplifier Replaces legacy Earth coverage array 3) Deployable reflector w/ phased array feed Modular 3-step construction Minimum assembly tooling Passive deployment mechanisms Compact composite shell folding scheme 6

7 Advanced L-Band Amplifier Technology for GPS Objective: Design, fabricate, and characterize performance of Advanced L-band Power Amplifier Engineering Development Units - Space Qualifiable/Suitable for GPS Payoff: Lower s/c power for same signal strength - Less mass/cost for power system Improves efficiency for same signal strength - Enables denser layout, decreases thermal subsystem requirement Increased signal strength for Anti-Jam Decrease part count in boxes Decrease number of boxes Contractor Efforts: Ball Boeing Northrop Grumman Acquisition Status: Awarded in May/Jun 2014 EDU and TRL 5+ by FY17 Threshold Objective Increased η (%) 45% 60% Increased Power (W RF out )

8 Flexible Digital Payload Legacy GPS payloads built to fixed signal requirements S&T Effort: On-orbit Reprogrammable Digital Waveform Alternate Generator (ORDWG) Spreading Codes ORDWG BAA was released in April 2015 and Overlays Multiple awards expected January 2016 Capabilities Flexibility in anti-jam, anti-spoof signal approaches Mitigates satellite obsolescence Allows exploitation of future advances in signal processing Reduces costly design changes during spacecraft development Signal Combining and Precision Power Allocation Current POCET Combining: Model vs Actual Quadrature Scatter plot Experimental Waveforms POCET = Phase- Optimized Constant-Envelope Transmission In-Phase 8

9 Space Atomic Clock S&T Goals of advanced atomic clock S&T Increase long & short-duration clock stability Improve Clock Frequency Stability from 1 x / τ (Rubidium) to < 1 x / τ Emphasis on manufacturability & material availability Tech need date of 2020 Partnered with DARPA, JPL, NIST, USNO, Aerospace, and NRL Investigating multiple technical approaches downselect in 2017 Committed to long-term investment in clock S&T for GPS and IMUs Detection Ramsey cavity State Selection Source 9

10 AETAM (Accurate Ephemeris Through Active Maneuver) Small thrust applied Predicted position Actual orbit Drag Force On-board accelerometer Laser ranging residuals referenced to GPSbased orbit solutions Objective Actively fly satellite to a known orbit on-board accelerometers to measure solar radiation pressure correct flight to predicted orbit using small thrusters Results No need to download almanac data Time To First Fix (TTFF) reduced Reducing dependence on navigation data message increases the resiliency of the signal Potential to alleviate signal processing requirements: +12 db gain J. Li et al. Advances in Space Research 40 (2007)

11 ANGELS Additional AFRL PNT Related Space Flight Experiments GPS for GEO and high performance accelerometers Uses advanced algorithms from NASA to receive GPS side lobe signals and generate near continuous navigation solutions Small Satellite Program (SSP) C/NOFS DSX 11

12 Small Satellite Program PNT Related Efforts ARMADILLO FOTON GPS Dual- Frequency GPS receiver with Nano- Satellite SWaP 0.5U form- factor (8.3 x 9.6 x 3.8 cm) ~1.5W orbit average w/ duty cycling SoVware defined receiver Simula=ons predict ~1.5M precision w/ iono delays Improved Kalman Filter precision GlobalStar PNT Enabler Enables near- global PNT data availability Simplex beacons with TLM data available ~10 sec aver deployment Affordable method to gather TLM data ~0.5 cents/byte EM + FM Simplex Radio = $6k Using GlabalStar for course ephemeris determina=on Namaru GPS (Australian) Developed by AUS Defense Science and Technology Group (DSTG) 8.2 x 8.2 cm board ~1.2W orbit average w/ duty cycling ~10M accuracy as single unit Sub- Meter rela=ve posi=on accuracy when mul=ple units flown in forma=on CHOMPTT 3U CubeSat precision =ming satellite equipped w/ an atomic clock synchronized with a ground clock Atomic clock, retroreflector, photo detector, and event =mer on SV SLR facility referenced to ground atomic clock Timing data sent via modulated laser pulses Demonstrate technology for enhanced GPS and future disaggregated naviga=on systems 12

13 Communication/Navigation Outage Forecasting System (C/NOFS) Reentry expected Nov 15; apogee 340 km, perigee 290 km and falling. Payloads characterize the space environment; include CORISS* GPS receiver. GPS PNT improves tracking where observations are marginal (low-altitude,13 inclined orbit). GPS PNT also enhances data assimilation for data-starved density / drag models vs ground-based observations. Accurate measurements: sub-meter vs 100s of meters and m/s vs 10s of m/s High data density, easily accessible, and unclassified Goal: Implement data assimilation techniques to update drag model parameters (coefficient of drag, area-to-mass ratio). Combines satellite environment knowledge with GPS data for more accurate drag models. Force Modeling Ini=al Condi=on Trajectory Propaga=on Data Assimila1on Model Update Data Posi=on/ Velocity Solu=on Error Residual C/NOFS provides: Plasma density Neutral density & pressure Electric & magne1c fields Ion velocity, temperature, & composi1on Total electron content PNT *CORISS: C/NOFS Occulta1on Receiver for Ionospheric Sensing and Specifica1on 13

14 DSX - Mission Objec=ves Nominal orbit: 6000 x km, 42 degree inclina=on Launch Sep 2016 on STP- 2 Mission SpaceX Falcon Heavy launch vehicle from KSC Three Main Science Experiments: 1) Wave- Par=cle Interac=ons (WPIx) prime payload MEO slot region orbit Determine efficiency of injec=ng VLF waves into space plasmas in situ Determine distribu=on of natural & man- made ELF- VLF waves Characterize & quan=fy wave- par=cle interac=ons 2) Space Weather (SWx) Map MEO radia=on & plasma environment Determine in- situ environment for wave genera=on experiments in (1) 3) Space Environmental Effects (SFx) Quan=fy MEO environment effects on technologies (electronics, materials, coa=ngs) Determine physical mechanisms leading to materials breakdown in MEO radia=on MEO = Medium Earth Orbit, ELF = Extremely Low Frequency, VLF = Very Low Frequency, KSC = Kennedy Space Center 14

15 Conclusion AFRL committed to strong PNT S&T investment consistent with National priorities NTS-3 Flight experiment will be impactful We value innovation, strong PNT vision, adding resiliency and synergistic partnering Looking for partnerships for NTS-3 & your ideas Also looking for bright, motivated PNT experts who love green chile! 15