The "Boreas" concept for imaging polar winds from the Iridium-NEXT constellation

1. The "Boreas" concept for imaging polar winds from the Iridium-NEXT constellation Dennis Chesters/NASA, Lars Peter Riishojgaard/JCSDA August 2008

2. Busted Forecasts 5-day forecasts in the mid-latitudes are "busted" every month Goddard Space Flight Center Competition Sensitive

3. Sensitivity to Arctic Winds Forecasts are "busted" by the effects of unobserved arctic disturbances, such as the effect of "Albert clippers" upon eastern N. America Goddard Space Flight Center Competition Sensitive

4. Science Objectives • Medium-range weather forecasts can be improved using satellite-based polar wind measurements • Successful science demonstration by JCSDA/ECMWF of improved forecasts ("no-busts" and accurate hurricane tracks) from MODIS polar overpasses that measure mid-tropospheric winds using the 6.7 micron water vapor channel Goddard Space Flight Center Competition Sensitive

5. Feature-tracked winds - GEO + MODIS MODIS gap GEO's gap MODIS Goddard Space Flight Center Competition Sensitive

6. Impact on Medium-Range Forecasts Goddard Space Flight Center Competition Sensitive

7. Economic Benefits of MODIS Polar Winds " Economic Benefits of Polar Winds from MODIS and GOES-R Winds ", R. Reining, J. Sterling, G. Dittberner and E. Miller, MITRE/NESDIS study, AMS Annual Meeting, January 2008 Goddard Space Flight Center Competition Sensitive

8. Mission Need • Drift winds are not observable in the arctic from GEO • No mid-IR water vapor channel on VIRS/NPOESS in the next decade • Single LEO satellite overpass of the pole is too infrequent • Need frequent satellite images of pole in mid-IR water vapor channel and thermal window • EITHER: dedicated "GOES to the pole" in Molniya orbit (GOES-like $250M mission) • OR: LEO guest imagers swarm the pole ("guests" on Iridium, <$60M instruments) • Relevance: societal benefit from improved weather forecasts • Un-met needs at NOAA, FAA, DoD for arctic winds • World Meteorological Organization (WMO) future vision calls for satellite-based polar winds • Research-to-Operations • "Venture class" NASA mission • Focused Earth Science • Flight of opportunity • <$100M Goddard Space Flight Center Competition Sensitive

9. Mission Opportunity • Iridium LLC is seeking science payloads for the next generation constellation • Launch, operations, and data delivery infrastructure built-in • Mass production = low unit cost • Orbit parameters • 11 satellites @ 780 km in 6 planes @ 84 degree inclination @ 11 minute overpasses • Launch vehicle -- commercial multi-sat launches • Launch Dates: Iridium LLC plans for 2013 though 2016 Goddard Space Flight Center Competition Sensitive

10. Current Mission Concept • "Boreas" Instrument -- small, robust, autonomous IR pushbroom imager • Uncooled microbolometric thermal IR array • 6.7, 8.5, 11 & 12 micron bands, 2 km resolution, ~15 min cadence • Miniaturized, autonomous attitude determination, milliradian accuracy • Iridium-specified envelope: <25 kg, <50 W, <1 Mbps, <0.2x0.3x0.5 m • "Bolt and go" simplicity, 5 year design life with graceful degradation built-in • Can lose 30% of sensors before mission is impaired --> 15 years of operations • Minimal Constellation • 3 orbits each half-populated with 4 imagers -- winds 6x per day • "Pathfinder" development -- launch one early (2013) & then build the rest (2016) • Cost Estimate (<$60M for instrument development & production) • <$20M NRE for first instrument production and testing • <$3M per GFE instrument -- industry builds 14, Iridium flies 12 • $TBD • Cost of launch, operation, data delivery from Iridium LLC • Cost of automated wind determination at a TBD-operated ground station Goddard Space Flight Center Competition Sensitive

11. Small Thermal IR Microbolometer Camera • 640x480 focal plane array • +/-0.05 C NEDT @ 30 Hz • 100x TDI for more signal • flown at Mars for 7 years • 3 Watts • 126 gm • <7x7x7 cm Goddard Space Flight Center Competition Sensitive

12. Miniature Star Tracker • 300 gm • 3 Watts • <6x6x8 cm • +/-0.3 millradian @ 1 Hz • “lost in space” recovery within 3 seconds Goddard Space Flight Center Competition Sensitive

13. 3 Cameras & 2 Star Trackers per“Boreas” instrument • 3 wide-FOV cameras for horizon-to-horizon imaging • 2 star trackers pointing 90 degrees apart • Field-programmable gate arrays to handle data • 4 IR strip filters (not shown) at 6.7, 8.5, 11 & 12 microns • 15 kg, 10 W, 0.6 Mbps in a small package Goddard Space Flight Center Competition Sensitive

14. 4 Boreas in each of 3 Iridium orbits Goddard Space Flight Center Competition Sensitive

15. Flexible Mission Coverage Scenarios • Scenario-3 smoothly sample 60-70 N • 3 satellite wind-triplets, 9 min apart • phased polar overpasses • 1 or 2 instruments busy at any time • 90 minutes data per cap-scan • observations of pole 90% duty cycle • <4 hr gap in observations at 60N • see figures • Scenario-1 for "snapshot" imagery • 3 satellite wind-triplets, 9 min apart • simultaneous polar overpasses • 9 instruments busy at same time • 30 minutes data per cap-scan • observations of pole 30% duty cycle • <5 hr gap in observations at 60N • not shown • Scenario-2 for less bursty imagery • 3 satellite wind-triplets, 18 min apart • simultaneous polar overpasses • 3 instruments busy at same time • 50 minutes data per cap-scan • observations of pole 50% duty cycle • <5 hr gap in observations at 60N • not shown Goddard Space Flight Center Competition Sensitive

16. Robust Features of Boreas on Iridium • Technologically Ready • Microbolometric imaging 10 years old • Microbolomer camera orbiting Mars • DOD funded micro star trackers • Simplicity • Bolt & go design • No moving parts • No cryogenics • No calibration sources • Redundancy • 3 independent cameras per instrument (left/center/right) • 2 independent star trackers per instrument (left/right) • 3 orbits @ 60 degree intervals • 3 instruments + 1 spare per orbit • 12 instruments to orbit + 2 spares • Risk minimization • Protoflight 2 years before group launches • Mass production, integration & testing Goddard Space Flight Center Competition Sensitive

17. Boreas-on-Iridium Applications • Application Areas • Weather, Disaster Management, and Air Quality • Potential Applications • Improved weather forecasts of storm tracks • Civilian and Military aviation route and air traffic management planning • Early warning for severe weather conditions while flying polar routes • Real time tracking of volcanic plumes • Additional Considerations • Efficiency in real time data dissemination and distribution • Potential End Users • National Oceanic and Atmospheric Administration • Federal Aviation Administration • Department of Defence • Department of Transportation • Federal Emergency Management Agency • State and Local government • Airlines • Electric Utilities Goddard Space Flight Center Competition Sensitive

18. Government/Commercial Collaboration • Technical readiness • An inexpensive, robust imager with built-in attitude determination can be flown on Iridium-NEXT without significantly impacting their commercial operation • Successful Instrument Design Lab study under GSFC IRAD, February 2008 • Programmatic issues • Iridium LLC has identified a half-dozen potential guest instruments, and is negotiating • NOAA is formally soliciting industrial partners to fill un-met needs, February 2008 • NASA's role: do what it does best -- space-borne radiometry • TBD: a business plan for guest instrumentation between Iridium LLC and governmental customers for high latitude winds Goddard Space Flight Center Competition Sensitive