The Cloud-Aerosol Transport System (CATS) Patrick Selmer, CATS Operations Lead Matthew McGill, PI & PM John Yorks, Science Lead & Algorithms A New Earth Science Capability for ISS

ISS | Earth Science CATS Program Overview

The Cloud-Aerosol Transport System (CATS) instrument is an attached payload for the JEM-EF Payload Developer is NASA-Goddard Space Flight Center Project was initiated in April month schedule from ATP to instrument ready The CATS project has three simultaneous goals: Provide long-term (6 months to 3 years) operational science from ISS Prove that low-cost, streamlined project approach can work (i.e., demonstrate a build-to-cost approach is viable) Provide tech demo on-orbit (target ACE mission) high rep rate laser photon-counting detection UV (355 nm) laser operation in space HSRL receiver concept ISS | Earth Science CATS Program Overview

CATS is ready to ship and launch all payload-level environmental testing completed JAXA and JSC verifications completed; PSRP paperwork completed CATS is ready to ship to SpaceX for integration and launch (SpaceX-5) originally targeted for HTV5 launch in late 2013, has been shifted multiple times to accommodate launch vehicle schedules. payload is fully compatible with both HTV (HCAM mount) and SpaceX (FSE mount) for launch. CATS will prototype the “robotic hand-off” from SpaceX, using SSRMS, to JEM-EF using JEMRMS. Payload mounts to JEM-EF EFU #3 mass 490 kg power ~500 W uses JEM-EF coolant loop data rate ~2 Mbits/second via MRDL and/or HRDL uses 1553 for commanding ISS | Earth Science CATS Program Status

Although CATS is designed to be safe for EVA operations, there is no planned use of EVA personnel Also no crew time requirements and, aside from installation, no robotic requirements On-orbit operations will be conducted through ground control only, using real-time commands “critical commands” to enable laser operation are reserved to PRO JEM-EF power on/power off commands are via CANSEI Flight rules require payload not operating laser during EVA and visiting vehicle/proximity ops Also, cannot park JEMRMS under the payload (i.e., in the laser beam). CATS is intended to operate continuously (or as near-continuously as possible) excepting periods when the system has to be off for safety reasons. CATS is designed to operate minimum 6 months, with goal of 3 years and option to extend to 5 years (hardware is certified to 15 years for structural integrity) ISS | Earth Science CATS Operations

The Cloud-Aerosol Transport System (CATS): A New Earth Science Capability for ISS CATS Science Overview

CATS Processing Center NASA GSFC ISS Operational Aerosol Forecast Models VOLCANIC PLUME TRACKING AIR QUALITY MONITORING CLOUD PROPERTIES WILDFIRE DETECTION AEROSOL PROPERTIES Research Forecasting ISS | Earth Science CATS Science Applications

Saharan dust boundary layer aerosol subvisual cirrus cirrus low-level cumulus convective clouds Lidar profiling generates a time-height cross-section of the atmosphere, revealing cloud and aerosol structure. Multiple cloud/layer features can be measured, up to the limit of signal attenuation (O.D. 3-4). From this data we derive layer boundaries, optical depth, extinction, and depolarization, and at least a coarse discrimination of aerosol type (e.g., smoke, dust, pollution). ISS | Earth Science Why Use Lidar?

Extend CALIPSO data record for continuity of Lidar Climate Observations – Continue record of vertical profiles of cloud/aerosol properties – Improve our understanding of aerosol and cloud properties and interactions – Improve model based estimates of climate forcing and predictions of future climate change ISS | Earth Science Science Goals (1) s2015 ACE 2013 HSRL likely to launch in 2016 Space- based mission, launch 2020s HSRL Demonstration for ACE Mission Bridge the data gap between CALIPSO & EarthCARE Launch late month requirement, 3 year goal Launched 2006 Using 2 nd laser since 2009 (~2.5 year life)

Improve Operational Aerosol Forecasting Programs – Enable aerosol transport models by using near real-time data downlink from ISS – Improve strategic and hazard warning capabilities of events in near real-time (dust storms, volcanic eruptions) – Demonstrate multi-wavelength cloud and aerosol retrievals for future missions ISS | Earth Science Science Goals (2) Snapshot of GEOS-4 model global aerosol distribution forecast for March 20, 2006 Orange = dust; Blue = sea salt; Green = smoke and sulfate; Saturation ~ species column amount ISS orbit. The low-inclination orbit permits extensive measurements over aerosol source and aerosol transport regions.

Ice CloudsWater CloudsDustSmokeSea Salt Vertical profiles of backscatter provide important climate information on Earth’s radiation budget However, layer type (i.e., composition) cannot be determined using backscatter at a single wavelength Determining layer type is important because: –Different layers have different microphysical properties which impact radiative balance in different ways –Climate models need to know the vertical/horizontal distribution and properties of atmospheric layers –Current climate models do not accurately predict the vertical structure of cloud and aerosol layers –Lidar data can be used to initialize models for better vertical structure in model output We want to take the measured profile data And turn it into a vertically-resolved “feature mask” that identifies the different types of layers. ISS | Earth Science Backscatter Measurements

Depolarization ratio (  ) provides information about particle shape Multiple wavelengths provide information about particle size by ratio of the backscatter (color ratio,  ) Both are needed to accurately determine layer type Ice Clouds:  > 0.40  > 0.85 Dust: 0.20 <  < 0.30 Water Clouds:  ~ 0.0  > 0.85 Smoke:  ~ 0.20 ISS | Earth Science Multiple Wavelengths and Depolarization

ISS | Earth Science CATS Data Products Level 1 Data: Relative Backscatter (L1A) Calibrated Backscatter and Depolarization Ratio (L1B) Res: 60 m (vert.), 350 m (hor.) Level 2 Data: Vertical Feature Mask Backscatter and extinction profiles Layer optical depth, lidar ratio Res: 60 m (vert.), 1-5 km (hor.) Level 0 Data: Raw Photon Counts for each channel in sequential order Res: 60 m (vert.), 350 m (hor.) Ice Clouds Water Clouds Dust Smoke Sea Salt

spot separation: 1.5 cm Laser #2a,b Modes (532/1064 and 355 nm) Laser #1 Mode (532/1064 nm) 7500 m/s TOP VIEW SIDE VIEW 7 km spot separation: 1.5 cm m diameter 405 km m diameter -0.5 o +0.5 o 7 km ISS | Earth Science Geometry/Operating Modes

The Cloud-Aerosol Transport System (CATS): A New Earth Science Capability for ISS The CATS Instrument A Class D Approach To Obtaining Important Earth Sciences Measurements From The ISS

ISS | Earth Science CATS Payload Overview SpaceX FSE Telescope aperture cover PIU FRGF H-fixture

As-built, prior to installation of blanketing. ISS | Earth Science Yes, it’s real: the CATS Payload As-Built Well, hello, kitty! Standard JEM-EF payload volume: x x m.

CATS will bridge a critical data gap in climate data record from lidar, improve operational aerosol forecasting, and contribute to future NASA mission development. CATS is a spectacular opportunity, and the latitude given by the ISS Program to apply sound engineering and management judgment in the pursuit of generating good science has been demonstrated to work. ISS Program trusted the Payload Developer to derive our own science requirements instead of subjecting the project to externally-derived requirements and oversight Instrument design and requirements are consistent with the [self-generated] science requirements. Schedule and budget were aggressive, and the CATS team delivered on time and on budget….we’re ready to integrate and launch ISS | Earth Science Summary

Details of CATS commanding, etc., can be discussed at the CATS-specific splinter meeting on Thursday afternoon. ISS | Earth Science CATS-specific Session