National Aeronautics and Space Administration/Goddard Space Flight Center, Code 285, Greenbelt, MD 20771

99 -- STEERABLE S-BAND MEDIUM GAIN ANTENNA SYSTEM POC Fernando A. Pellerano (301)286-8967, e-mail at ''fernando.a.pellarano @gsfc.nasa.gov''. Contracting Officer: Elizabeth J. Austin, e-mail at ''liz austin_at_280@ccmail.gsfc.nasa.gov''. The Telecommunications Systems Branch of the NASA/Goddard Space Flight Center requests information on interest and capability in developing a steerable S-band Medium Gain Antenna System for the Perseus Family of Unmanned Aerial Vehicles (UAV). UAV's are becoming increasingly useful and necessary for atmospheric research. The Perseus, developed by Aurora Flight Sciences Corporation for NASA/Ames Research Center, is one family of aircraft that NASA is currently using for these purposes. Some of the planned missions will carry aircraft beyond the line-of-sight of ground stations and will require satellite communications with the aircraft. The NASA Tracking and Data Relay Satellite System (TDRSS) would be used. Link analyses have shown that a 14.0 dBi, steerable medium gain antenna system will meet the requirements. The basic requirements are summarized as follows: 1) Maximum envelope dimension - 7 inches in the height dimenision (the structure cannot impact the aircraft's aerodynamics) 2) Weight - (12 lbs. 3) Transmit frequency - 2.2875 GHz 4) Receive frequency - 2.1064 GHz 5) Input RF power - 5 Watts nominal, 20 Watts maximum 6) Bandwidth - 1MHz 7) Field of View (FOV) - a)elevation - 115 degrees (from aircraft zenith to 25 degrees below the aircraft horizon) b) azimuth - 360 degrees 8) Slew Rates - a) elevation 16 degrees/sec b)azimuth - 3 degrees/sec 9) Minimum Gain - 14 dBi (over entire FOV) 10) Polorization - Left hand circular 11) Axial Ratio - (2 dB 12) Operating DC Power - (15 Watts 13) Voltage source - 28 volts aircraft bus 14) Temperature- -60 degrees C operational 15) Pressure - 1,000 mbar to 10 mbar 16) Ultimate Load (1.5* Design Load) a) longitudinal - 7.50 b) vertical - 7.00 c) side - 2.50 17) Vibration - 50Hz to 300 Hz at 3g 18) Lifetime - 5 years minimum. Please provide the physical and performance characteristics of such an antenna, its associated radome, and the antenna controller. This request is not limited to mechanically steered systems. Any system, whether mechanically or elelctronically steered, or both, can be presented as long as basic requirements are met. The link analysis from which these requirements were derived assumed a separate transmitter with 5 Watts RF output, 1.0 dB passive losses, and 0.4 dB pointing/polarization losses, for a total EIRP of 19.6 dBw. Integrated antenna/amplifier systems with a low power input from the modulator can also be addressed (the modulator should not be addressed as part of the antenna system). Please provide a rough estimate of the cost and development schedule, as well as your company's flight heritage for this technology. Any suggestions that significantly simplify the system and/or reduce costs are welcome. Please provide responses by April 15, 1995. Please note that this is not a Request for Proposal but a Request for Information only. (0079)

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