Preparing for a Wind Lidar Venture Class Mission Discussion at Lidar Working Group Meeting Bar Harbor, ME August 24 – 26, 2010 Dr. Wayman Baker 1

Objectives Summary of Draft Statement of Work (SOW) for IDL/MDL Study of Feasibility of Deploying a DWL on the ISS 2 1.Beginning with the NWOS design, the IDL will scale lidar energy, prf, and aperture to match the ISS orbit; 2.The NASA/GSFC Mission Design Laboratory (MDL) will design an updated GWOS FRAM/ELC-type payload for the ISS based on the new instrument concept, using the earlier GWOS data requirements and the ISS capabilities; The IDL/MDL will assess technology readiness, risk, and cost for an updated GWOS instrument and ISS mission; 3.The IDL/MDL will provide a preliminary determination for a suitable launch vehicle. Note: The ISS Program will make the final determination.

Assumptions Summary of Draft Statement of Work (SOW) for IDL/MDL Study of Feasibility of Deploying a DWL on the ISS 3 1.A demonstration mission that will not be held to operational lifetime, duty cycle and data download requirements; 2.DWL instrument based on existing GWOS and NWOS concepts, both using the hybrid approach; and, 3.Pointing issues would be handled with “knowledge” rather than “control” (i.e., no gimbaling)

4

IDL SOW Summary of Draft Statement of Work (SOW) for IDL/MDL Study of Feasibility of Deploying a DWL on the ISS 5 The instrument design will meet GWOS data requirements using a hybrid DWL and the ISS 51 degree inclined orbit. It will continue taking data through the earth shadow portion of the orbit. The IDL will: Incorporate any improvements from NWOS, airborne experience, and technology advances to define an updated GWOS instrument conceptual design for the ISS; Use the GWOS data requirements and ISS capabilities; Use shared optics (coherent detection and direct detection lidars) with 4 azimuth angles, crossed-beam optical design, and 45 degree zenith angle as in NWOS; Review NWOS trades in power, mass, volume for 100% duty cycle vs. 50%; Use two-year technology projections, and provide estimates for time and cost to achieve projected technologies; Notes: Would 2 telescopes save significant $ vs. 4 telescopes? With 2 telescopes, maybe the 355 could do the fore perspective and the 2053 do the aft? (MK) Use liquid laser cooling rather than further R&D on conductive cooling. (MK) How about resupplying lasers instead of laser redundancy? (DE) Could an astronaut/mission specialist make a repair? (WB)

IDL SOW (Cont.) Summary of Draft Statement of Work (SOW) for IDL/MDL Study of Feasibility of Deploying a DWL on the ISS 6 For the ISS environment:  Update GWOS instrument development and implementation cost;  Mass, volume, and dimensions of major components of the instrument (e.g., transceiver, optics);  Thermal requirements;  On-board computational requirements;  Downlink bandwidth; and, instrument vibration modes.  Assume a GWOS 3 year mission life, assess the redundancy of critical components with respect to mass, volume, power, and cost. Would a mission life of 3 years be a significant cost driver versus, 1 year, in terms of component redundancy, etc.?  Assume the NWOS concept with a reduced instrument volume using a crossed- inward optical design. Could the reduced instrument volume result in the use of a smaller launch vehicle?  Update and document the efficiency estimates for the laser, optics, and detectors;  Identify any technology or engineering “tall poles” and risks;  Identify any special spacecraft/instrument/ISS interface requirements from the instrument perspective; and,  Identify any potential instrument advantages/disadvantages from operating in one of the ISS attached modules, e.g., the pressurized Japanese Experiment Module.

MDL SOW Summary of Draft Statement of Work (SOW) for IDL/MDL Study of Feasibility of Deploying a DWL on the ISS 7 For the ISS environment, the MDL will design an updated GWOS mission for the ISS using the earlier GWOS data requirements. The mission design will address the following: The operation of the instrument in the ISS environment; Instrument accommodation on the ISS, including any issues related to: - High frequency vibrations; - Slow attitude changes, i.e., from drifts, reboosts, etc.; - Available power (average and peak); - Thermal management; - EMI/EMC; - Contamination effects such as water dumps, approaching vehicle rocket plumes, etc.; - Service and component replacement on orbit; - Data rates (uplink and downlink); and, - Unobscurred nadir view at design nadir angle (e.g., 45 degrees).

MDL SOW (Cont.) Summary of Draft Statement of Work (SOW) for IDL/MDL Study of Feasibility of Deploying a DWL on the ISS 8 Ensure the following areas are in compliance with the FRAM/ELC requirements: Mechanical; Power; Thermal; Flight dynamics; ISS mission operations; Command and data handling; Data systems; Smallest launch vehicle possible, including trades against the requirements; Launch; Reliability; and, Disposal. Estimate mission cost for lifetime recommended by the IDL study; Identify any unique costs related to operating in a manned environment; Identify any technology or engineering “tall poles;” and, Identify special spacecraft/instrument/ISS interface reqts. from a mission perspective. Notes: Would data latency of 30 min be a major cost driver vs. 90 min, 150 min (WB)? Don’t require quick data downlink—accept slowness of whatever link is free (M.K.&L.P.R.). Don’t require vibration isolation—accept when the astronauts ruin the data (M.K.).