1. The PECOS Low Earth Orbit Space Weather Satellites NSF Small Sat Conference 15 - 17 May 2007 O. de La Beaujardière, F. J. Rich, D. A. Cooke, J. Mozer, Space Weather Center of Excellence Air Force Research Laboratory, Space Vehicles Directorate L. C. Gentile Boston College Institute for Scientific Research

2. 2 PECOS: Small LEO SWx Sats Overview Introduction / rationale DMSP / POES / NPOESS status Proposed LEO constellation –Polar and Equatorial Comm/nav Outage Satellites (PECOS) for SWx needs in ionosphere and neutral atmosphere –Notional architecture based on small satellites in 3 different types of orbits Mission study and challenge to science community Conclusion C/NOFS NPOESS DMSP

3. 3 Introduction Looming crisis in U.S. space weather capabilities Space Environment Sensor Suite (SESS) no longer on NPOESS Last DMSP launch ~2012 AF Space Command, AFRL and others developing comprehensive plan to specify and forecast natural space environment in post-DMSP era Recommendation: PECOS (Polar & Equatorial Comm/nav Outage Satellites) small LEO satellites to meet ionosphere / thermosphere SWx requirements and ensure continuity of DMSP capability Predicted Position Actual Position

4. 4 Rationale Air Force is responsible for DoD space weather Understanding and forecasting space weather are key to ensuring SWx mission success AF Space Command seeking funding in 2010 as ‘capability disconnect’ Objectives of proposed PECOS mission –Nowcast and forecast of ionosphere and thermosphere conditions Provide tools for DoD and civilian systems for communication, navigation, surveillance Coordinated effort by DoD and civilian agencies to meet U.S. space weather requirements Transition from DMSP era to 21 st century provides exciting opportunities for new technology development –Smaller satellites –Lighter payloads –Flexible launch options

5. 5 PECOS Small Sats for SWx AFSATCOM Polar Ionospheric Disturbances GPS Equatorial Ionospheric Disturbances UFO & FLTSATCOM Magnetic Equator Mid-latitude Scint & TEC Polar Cap Scintillation Equatorial Storm Effects Scintillation Forecasts Satellite Drag PECOS provides capability to specify and forecast ionospheric and thermospheric impacts on satellite systems.

6. 6 Present Capability DMSP Orbits F15, 2112 LTAN F14, 1926 LTAN F13, 1828 LTAN F16, 2003 LTAN F17, 1736 LTAN Primary Back-Up LTAN = Local Time of Ascending Node @ Launch 4 or 5 DMSP satellites on orbit at any time As of Feb 07 DMSP

7. 7 Magnetometer Thermal Plasma Sensor Auroral Particle Detector Ultraviolet Disc Imager Ultraviolet Limb Imager DMSP Block 5D-3 (F16-20) POES Space Environment Monitor (SEM-2) DPU MEPED TED DMSP and POES Current SWx Sensors in Polar Orbit

8. 8 Nunn-McCurdy Impact SEM is the only Post-Nunn-McCurdy NPOESS SWx sensor Space Environment Monitor (SEM) DPU MEPED TED Magnetometer Back Side Thermal Plasma Sensor Ultraviolet Disc Imager Ultraviolet Limb Imager Auroral Particle Detector

9. 9 PECOS A Proposed Solution for SWx PECOS is LEO mini-satellite constellation, 3 types of orbits PECOS High -- Polar orbit, altitude ~ 800 km, sun synchronous PECOS Low -- Polar orbit, low altitude < 350 km PECOS Equator -- Equatorial orbit, low altitude Objectives –Meet DoD priority requirements in ionospheric density, scintillation, and satellite drag –Meet NPOESS IORD I space environment Environmental Data Records (EDRs) –Maintain current DMSP capability to ensure long-term continuity of space environmental monitoring –Leverage new technology development for future operational systems Large TEC plume disrupts nav, comm, and surveillance systems

10. 10 PECOS High -1 DMSP-type polar orbit: ~ 700 to 900 km altitude Nominal 2-satellite constellation at ~ 14:30, 21:30 LT Objective: achieve DMSP functions Instruments: –Mini-UV spectrograph / imager (s) Electron density Neutral atmosphere composition (O/N 2 ) Auroral precipitation Equatorial scintillation –Thermal plasma suite Drift velocity, electric field Temperatures Ti, Te Electron density and density fluctuations GUVI

11. 11 PECOS High - 2 Instruments (continued) –Magnetometer on short boom Currents Total electromagnetic energy Penetration electric fields –Particle detectors 20 eV - 10 MeV for electrons 20 eV - 300 MeV for protons –Scintillation (DORIS) and GPS receiver Electron density profile Scintillation, comm/nav outages Possible launch scenario: –2 satellites on same Minotaur –Desired LT orbits reached after time and altitude change Considering topside sounder on separate satellite (Tacsat 5)

12. 12 PECOS Low Polar orbit ~300 km perigee –Elliptical (apogee ~400) Primary objective: –Critical parameters for satellite drag Secondary objectives: –Electron density profile –Scintillation Instruments –Neutral wind monitor –Accelerometer Thermospheric density –Mass spectrometer Thermospheric composition –Thermal plasma suite Drift velocity, electric field Temperatures Ti, Te Electron density and density fluctuations ~12800 LEO objects in catalog Predicted Position Actual Position

13. 13 PECOS Equator Equatorial orbit (~13° inclination) –Apogee: ~700 km, Perigee: ~350 to 400 km Objective: Forecast low-latitude comm / nav outages –C/NOFS follow-on Instruments –Thermal plasma suite Drift velocity Temperatures Ti, Te Electron density and density fluctuations –Neutral wind monitor –Planar Langmuir probe Electron density, in situ irregularities –Scintillation (DORIS) and GPS receivers Electron density Scintillation, comm/nav outages –Electric and magnetic field suite Electric field Wave spectra Plasma irregularities C/NOFS

14. 14 Space Environment Monitoring Concerns and Options Input from SWx community needed to optimize notional PECOS configuration –Constellation, orbit, payload (< 100 kg) –New instrument designs Smaller in size, weight, power Higher resolution measurements for more accurate specification Operational systems must be based on proven technology Need to demonstrate technology readiness –Standard small-sat bus and interface recommended for all PECOS spacecraft AFRL Plug & Play satellites Ball Aerospace SIV sats for STP Other options –Adaptable launch configuration ESPA ring Minotaur Other

15. 15 PECOS Proposed Design Study End-to-end assessment of requirements: from space environment parameters to mission application – Systematic analysis of requirements and options to meet them – Operational analysis a critical component – Interagency team – Integrated approach leveraging data from other U.S. sources – Determine best strategy for operational and S & T development Opportunity to demonstrate viability of new small-sat technologies Proven technology required for operational systems GUVI EPBs

16. 16 Concluding Remarks AF is the responsible entity for DoD Space Weather AFRL SWx CoE is taking a leadership role to resolve crisis PECOS small sat system will meet DoD priority SWx requirements in ionosphere, scintillation and satellite drag – AFRL & AF Space Command studying possible architecture 2 to 4 sats on PECOS HI orbit (DMSP type) (primary for ionosphere, secondary for thermosphere) 1 or 2 sats on PECOS Low orbit (primary for thermosphere, secondary for ionosphere) 1 sat on PECOS equator (C/NOFS follow on) (primary for scintillation, secondary for iono and thermo) – Mission development plan will define optimal configuration of orbits, instruments, models – Provides opportunity to leverage new technology development for sensors, spacecraft, launch options Collaboration with NPOESS still needed –NPOESS ground segment will be a great asset Interagency coordination and collaboration are essential Plan urgently needed to ensure continuity of SWx monitoring in post-DMSP era If nothing is done soon, U.S. risks loss of capability to build and maintain space environment instruments

17. 17 Back-up Material Jicamarca Radar, Peru – Oct 22, 1996 GUVI C/NOFS DMSP

18. 18 DMSP & PECOS Notional Timeline

19. 19 NPOESS and PECOS Space Environment Sensor Suite (SESS) will not fly on NPOESS (outcome of Nunn-McCurdy review) AF Space Command seeking funding in 2010 as ‘capability disconnect’ – PECOS small satellites would cost less than NPOESS SESS Concerns with re-incorporating two sensors on NPOESS – Integration costs might not be borne by NPOESS IPO – NPOESS survival not assured – Does not meet SWx requirements and warfighter needs – Space weather is not prime concern for NPOESS Pre-Nunn-McCurdy SESS did not meet DoD SWx requirements – 2130 orbit, required for ionospheric scintillation, eliminated – Scintillation and magnetic field requirements not met – Electron density profile and neutral density profile marginal Collaboration with NPOESS still needed – NPOESS ground segment will be a great asset PECOS mission maintains long-term continuity of space environment monitoring for DoD SWx mission in post-DMSP era

20. 20 Scintillation and Ionospheric Specification for Comm/Nav/Surveillance Ionospheric density and irregularities affect DoD SSA mission Accurate forecast and specification of ionospheric parameters needed for: – Communication – GPS Navigation – Surveillance – Geolocation – HF communication – Missile defense Plasma Density Scintillation AF Goal: 72-120 hour space weather forecast

21. 21 Satellite Drag and Precision Orbit Determination Thermosphere (non-ionized part of upper atmosphere) affects satellite drag and reentry Accurate nowcast and forecast of thermospheric parameters needed for: – Precise satellite orbit determination – Avoidance of collisions with space debris – Satellite reentry prediction – Maintenance of space objects catalog (12800 objects) – Prediction of satellite positions – Mission planning support Design of space systems for long-term operations End-of-life plans Fuel and station-keeping – AFSPC Goal, 90 - 500 km: 5% drag error, 500 - 700 km: 10% error Predicted Position Actual Position

22. 22 Satellite drag is significant below 600 km Thermospheric neutral density controlled by: Solar EUV heating Auroral heating (particles and electromagnetic energy) Upward propagating waves from troposphere Density variability at 400 km Solar cycle: factor of 10 variation with EUV over 11 yr cycle Day-to-day: ~10% variability Storm events: Factor of 6 increase in a few hours Solar Wind Interaction Drivers for Satellite Drag/Neutral Density

23. 23 Present Capability DMSP SWx Instruments and Measurements Precipitating Particle Sensor (SSJ5) – 30 eV to 30 keV –Auroral Boundaries and Energy Deposition –Electron Density Profile Thermal Plasma Monitor (SSIES) –In Situ Electric Field –In Situ Plasma Density and Temperature Magnetometer (SSM) –In Situ Field-Aligned Current  of Joule Heat Obs. –Global Geomagnetic Disturbance  Proxy for Dst Index Extreme Ultraviolet Scanners / Photometers (SSUSI and SSULI) –Plasma Density (~200 to 600 km) –Auroral Energy Deposition & Auroral Boundary –Neutral Atmosphere Density and Composition AFRL responsible for all DMSP SWx instruments, except SSULI

24. 24 Present Capability DMSP Schedule DMSP F20 launch ~ 2012 NPOESS: 2013 for C1 launch MetOp: A in 2006, B in 2010 (?) FY07FY08FY09FY10FY11FY12FY13FY14FY15FY16FY17FY18 F15 F16 F17 F18 F19 F20 Guaranteed Life Expected Life FY15 is critical time to have new operational system in place; program planning should start in FY08

25. 25 Complementary Space Instruments Satellites / sensors presently on orbit –MetOp with SEM particle detector –JASON provides TEC above oceans –DMSP SWx sensors (while it lasts) –GRACE accelerometer –CHAMP accelerometer (while it lasts) –COSMIC Planned satellite missions –NPOESS Only SEM particle detectors (POES heritage) on one orbit –SWARM 3-satellite constellation for solid Earth magnetic field measurements, but no SSA contribution Proposed Missions –UV Imager at GEO orbit –COSMIC II with GPS, mini-UV and DORIS Rx DMSP COSMIC

26. 26 Complementary Ground-Based Instruments DORIS UHF/S-Band Beacons at Ground Sites SCINDA sites Coherent radars on a 24 / 7 basis Ionosondes All-sky cameras GPS Rx DORIS Tx Ground magnetometers Fabry-Perot Interferometers Incoherent Scatter Radars for campaigns SCINDA Ground Stations (2008 plan) Backbone SitesSupporting SitesUnited Nations IHY Sites 30N 0 30S 210E 240E 270E 300E330E 0 30E 60E90E120E 150E

27. 27 PECOS Development Issues Important technology progress expected in spacecraft design, instrumentation, interface, launch options Community input needed to assess – Spacecraft design / size – Instrument miniaturization – Standard interface options – Optimum orbits – Life time on orbit – Launch options – Telemetry / Real-time data need – Software, models – Impact on warfighter needs Balance cost / schedule / performance / technical risk SWx requirements tied directly to mission applications –Systematic analysis from SWx measurements to operations

28. 28 DMSP C/NOFS