Lars Peter Riishojgaard Global Modeling and Assimilation Office/ Goddard Earth Science and Technology Center HIGH-LATITUDE WINDS FROM MOLNIYA ORBIT a mission concept for NASA’s Earth System Science Pathfinder Program

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005 Mission overview Fly a geostationary-class atmospheric imager in a Molniya orbit Aim is to demonstrate capability of time-continuous coverage of atmospheric imagery and winds for all of the northern hemisphere (“GOES to the pole!”) Scientific heritage provided in part by GOES/Meteosat, in part by the MODIS winds Mission can help fill the “water vapor gap” between MODIS and NPOESS (VIIRS FM4) Potential for a substantial future upgrade to the GOS Proposal being developed by the Goddard Space Flight Center for NASA’s Earth System Science Pathfinder program

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005 Primary science application: High-latitude winds –Known shortage of high-latitude wind observations –Mid-latitude forecast busts often have high-latitude origins –(Winds from MODIS shown to have positive impact especially on sub-par forecasts)

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005

Status of satellite wind observations No operational satellite winds beyond deg latitude Polar winds from MODIS (until 2008) –Data latency is problematic; 4 to 6 hours after real time –Image refresh problematic; 15 minutes is optimal, MODIS: ~100 minutes –No water vapor channel on VIIRS (until at least 2015) –Latitudinal coverage gap between MODIS and GEO winds => Need for “geostationary-type” imagery over high- latitude regions; Molniya Orbit Imager is a good candidate

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005 Molniya orbit characteristics Highly eccentric Kepler orbit –Apogee height km (geostationary orbit height ~36000 km) –Perigee height ~600 km –Inclination 63.4 degrees –Orbital period ~11h 58m (half a sidereal day) Location of apogee w.r.t. Earth is fixed and stable! Platform in quasi-stationary imaging position near the apogee for about two thirds of the duration of the orbit Used extensively by USSR (to a lesser degree by the US) for communications purposes First suggested for meteorological applications by Kidder and Vonder Haar (1990)

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005

Example orbit (Molniya 3-53); all areas N of solid line visible from western cusp

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005

Additional applications for Molniya imagery Nowcasting for aviation, shipping, fishery, exploration users Volcanic ash monitoring (aviation safety) Polar lows and other intense/rapid weather systems –Nowcasting/forecasting –Development and life cycle Global change –Arctic is a sensitive region and an early indicator of e.g. climate change Sea ice extent and monitoring … possibly others (Multi Temp 2005 ?)

Molniya Orbit Imager Preliminary data products list

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005 High-level mission requirements High temporal (15 minutes) and spatial (1 km VIS, 2 km IR) resolution imagery for all regions of the northern hemisphere for multitemporal applications and derived products –a spacecraft in Molniya orbit is the most efficient single-satellite complement to the geostationary systems to achieve this goal –Full-disc view every 15 minutes within 60% of apogee –Special events rapid-scan capability: 1000 x 1000 km in one minute Nominal 3-year mission duration (goal is 5 years: ) –Nominal end of life for MODIS is 2008; no water water channel on VIIRS until 2015 (earliest possible date); 2010 launch strongly desirable Real-time “operational” dissemination of images and derived products

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005 Mission implementation studies Overall mission design based on series of concurrent engineering studies by the Integrated Design Capability at Goddard Key IDC results: –Mission is technically feasible and classified as “low risk” –Total costs of three-year mission: $212M Space segment –Instrument vendor selected –RFI for spacecraft issued on 04/22 through by the Rapid Spacecraft Development Office at Goddard Ground segment –NESDIS is helping to draft plans for data processing chain and has indicated possibility of ground support (Fairbanks station) –Finland has indicated possibility of ground support (Sodankyla station; data processing)

Lifetime36 months (goal: 60 months) Orbit718 min Molniya Visible Channel micron 1 km horizontal resolution IR Channels3.9 ( ) micron 6.3 ( ) micron 7.1 ( ) micron 11.0 ( ) micron 12.0 ( ) micron 2 km horizontal resolution Radiometric PrecisionVIS: SNR 100% albedo IR: K Radiometric AccuracyVIS: 6% IR: 1 K Field of View>24 degrees + star field Time to image a complete scene<15 minutes Input Power (baseline)< 180 W (including 20% cont.) Mass (baseline)<136 kg (including 30% cont.) Volume (baseline)<0.9 m x 1.2 m x 1.3m Instrument system requirements (from POD)

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005 Instrument Raytheon selected as partner for baseline ESSP mission –Design draws heavily on JAMI, a geostationary imager launched in February 2005 on the Japanese MTSAT-1R satellite –Main differences are: Scan mode (software change) Data processing (software change) Channels (new filters, different operating mode) Radiation environment (minimal impact) –Flight heritage (low risk) –Performance meets requirements in almost all areas

18 Molniya Orbit Imager (deployed configuration; Goddard IMDC) X Y Z Solar Array 4.0 m² shown 2.98m² required Dual axis drive Instrument Package Instrument ACE box Dual Axis Comm antenna Ø0.5m Instrument Thermal radiator Dewar Active cooler S/C Buss Ø1.0m x 2.25m 65 kg propulsion

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005 Science Team Lars Peter Riishojgaard, UMBC, PI Bob Atlas, GSFC, Simulation/impact experiments Dennis Chesters, GSFC, Instrumentation, mission Ken Holmlund, EUMETSAT, Algorithm development Jeff Key, NESDIS/ORA, Data processing Stan Kidder, CIRA, High-latitude applications Paul Menzel, NESDIS/ORA, Cloud applications Jean-Noël Thépaut, ECMWF, Global NWP applications Chris Velden, CIMSS/UW, Algorithm development Tom Vonder Haar, CIRA, Satellite meteorology

Molniya Orbit Imager, Multitemp 2005, Biloxi MS, 05/17/2005 Summary Molniya Orbit Imager to be proposed to NASA as a pathfinder for high temporal and spatial resolution imagery for regions beyond reach of the geostationary sensors Numerous applications, both scientific and operational –Primary initial thrust is numerical weather prediction; many other fields in Earth Science can benefit –Data from this mission are directly applicable to 6 of the 9 (and indirectly to all 9) GEOSS Societal Benefits areas The mission concept is steadily maturing; there is still time to influence this The mission is a prime candidate for national (e.g. NOAA, DoD) and international (e.g. ESA, EUMETSAT, NWS) collaboration