Submillimeter-Wave Spectrometer for Small Satellites VAST: Venus Atmospheric Sounder with Terahertz

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1 Submillimeter-Wave Spectrometer for Small Satellites VAST: Venus Atmospheric Sounder with Terahertz Theodore Reck, Brian Drouin, Adrian Tang, Cecile Jung-Kubiak, Imran Mehdi

2 Vesper Goddard managed Venus mission concept that included a JPL submillimeter Limb Sounder (SLS) to provide upper atmospheric science Dual tunable heterodyne receivers enable sub-parts per billion sensitivity for key chemical species and direct temperature, pressure, and Doppler wind measurements above the clouds Based on flight proven technologies from SWAS, Herschel, EOS Aura and the Rosetta MIRO instrument Science makes SLS very compelling, but Mass (44 kg) and Power (100W) make SLS a mission resource driver

3 THz Limb Sounding Venus Science Atmospheric dynamics, physics and chemistry 12 CO/ 13 CO winds ~10 m/s accuracy from km ~5 m/s accuracy from km Accuracy limited by SNR Temperature (also from CO) Determined in pressure level retrievals Trace species H 2 O, HDO, H 2 18 O (isotope ratios) H 2 O 2 O 2 ClO (catalytic agent) O 3 (catalytic agent) SO 2 OCS H 2 S NO (lightning) 11/29/2016 Submillimeter-wave Spectrometer for Small Satellites 3 jpl.nasa.gov

4 Miniaturization targets Take advantage of CMOS electronics and push on everything else Goal: Change 44 kg/100w instrument into <10 kg (2U) / <5W instrument 1. Miniaturize back-end spectrometers and supporting electronics (Tang) 2. Integrate both receivers into one block, using common LO source (Reck) 3. Reduce antenna footprint with on-axis design (Reck) 4. Develop waveguide switch for calibration (Jung-Kubiak) 11/29/2016 Submillimeter-wave Spectrometer for Small Satellites 4 jpl.nasa.gov

5 Current Status of VAST JPL Strategic Research & Technology Concept has been funded for FY17 Components already miniaturized Reference oscillator 100 GHz synthesizer 85 GHz amplifier 600 GHz receiver 600 GHz calibration switch Waveguide calibration loads IF amplifier chain 750 MHz spectrometer Synergy with PICASSO/MATISSE tasks 11/29/2016 Submillimeter-wave Spectrometer for Small Satellites 5 jpl.nasa.gov

6 Planetary Science Rationale Planetary science questions that can be addressed by the proposed instrument concept: 1. What are the wind speeds km in Venus atmosphere? 2. What are the vertical distributions and columns of CO, O 2, H 2 O, HDO, NO, ClO, SO, SO 2, OCS and H 2 S in Venus atmosphere? 3. What is the temperature profile of Venus stratosphere and mesosphere? 4. What compounds exist in Venus atmosphere that have not yet been detected by ground based or past flight missions? How well developed is the instrument performance model, and how confident are you that the proposed CubeSat/SmallSat architecture can meet key measurement requirements? The discovery class mission proposal concept Vesper contained a full performance model for the Submillimeter Limb Sounder that can now be realized in a cube-sat architecture with some graceful loss of expected capability. The development required for Cubesat implementation is detailed in back-up slides. 11/29/2016 Submillimeter-wave Spectrometer for Small Satellites 6 jpl.nasa.gov

7 Submillimeter-wave Spectrometer for Small Satellites 6U Enables small satellite-based submillimeter-wave instrument missions: v D/H ratio comet hunter to study the water formation processes of the solar system v Venus limb-sounder to characterize the distribution of gases, temperature profile, and gravity waves of Venusian atmosphere Milestones (all years) 2U Date CMOS Synthesizer and Spectrometer Demonstrated Q2, 2017 Flat Antenna Demonstrated Q4, 2017 Waveguide Calibrator Demonstrated Q4, GHz Receiver Designed Q4, GHz Receiver Demonstrated Q4, 2018 Instrument Integrated and Tested Q4, 2019 Initiative Long Term Objectives Develop flat antenna that can be mounted directly on a small satellite that does not require deployment Replace quasi-optical flip mirror calibration with compact waveguide calibrator Integrate CMOS synthesizer and spectrometer to radically reduce power consumption Expand bandwidth of receiver to capture important molecular species in Venusian atmosphere All tasks reduce power and mass of Submillimeterwave spectrometers to enable deployment on CubeSat/Small-Sat platforms Mission Outlook v Game changing potential for missions-ofopportunity o CubeSats are under intensive study to flesh out possibilities for difficult or expensive targets o Venus atmospheric dynamics and chemistry remain compelling o Reduces cost or increases scope for Discovery or New Frontiers mission v Instrument will no longer be the tall pole jpl.nasa.gov

8 jpl.nasa.gov

9 2U Instrument Concept Powered devices Watts Reference Oscillator GHz Synthesizer GHz Synthesizer GHz Amplifier GHz Amplifier GHz Reciever 0 500GHz Reciever 0 600GHz Calibration Switch GHz Calibration Switch Waveguide Calibration Loads 0.5 Optical Design 0 IF amplifier chain MHz Spectrometer 1 Total 4.71 Technology Developments in progress 1. Compact Cassegrain reflector 2. Integrated 500GHz receiver/tripler GHz Calibration Switch 4. 85GHz Synthesizer

10 Submillimeter-wave Spectrometer for Small Satellites Technical Approach Overview 10

11 Submillimeter-wave Spectrometer for Small Satellites Technical Approach Highlights 1. A flat, high gain (> 50dB) meta-surface antenna operating at 500 to 600 GHz that does not require deployment 2. A compact waveguide-based calibrator operating at 440 to 600GHz accurate to +/-2K 3. A low-power CMOS W-Band synthesizers with frequency coverage from 87 to 100 GHz with less than 250mW of DC power consumption and phase noise less than -85dBc/Hz 4. A low-power CMOS Spectrometer with 1GHz of bandwidth and 1024 channels consuming less than 1.2W 5. An integrated receiver operating from 440 to 500GHz with a noise temperature below 10,000 K 11

12 Submillimeter-wave Spectrometer for Small Satellites Technical Approach Highlights A flat, high gain (> 50dB) meta-surface antenna operating at 500 to 600 GHz Uses modulated surface-wave impedance to create radiating structure Result: Flat antenna with integrated feed Benefits: v Avoids feed deployment by integrating feed into antenna structure v Reduces mass of antenna by replacing metal machined reflector Feed (Simulated Beam Pattern) 12

13 Submillimeter-wave Spectrometer for Small Satellites Technical Approach Highlights A compact waveguide-based calibrator operating at 440 to 600GHz Benefits: v Enables calibration of receiver with flat antenna v Replaces massive, power-hungry, quasi-optical calibration schemes 13

14 Submillimeter-wave Spectrometer for Small Satellites Technical Approach Highlights A low-power CMOS W-Band synthesizers with frequency coverage from 87 to 100 GHz Benefits: v Reduces power consumption of LO system from 4W to 0.25W 14

15 Submillimeter-wave Spectrometer for Small Satellites Technical Approach Highlights A low-power CMOS Spectrometer with 1GHz of bandwidth and 1024 channels Benefit: v Reduces power consumption of spectrometer from 15W to 1W 15

16 Submillimeter-wave Spectrometer for Small Satellites Technical Approach Highlights An integrated receiver operating from 440 to 500GHz Benefits: v Increases the bandwidth of the receiver to cover additional molecules of interest at Venus v Reduces power consumption by 2-3W by utilizing same LO 16

17 Submillimeter-wave Spectrometer for Small Satellites Deliverables Deliverables (first year): 1. Flat Meta-surface Antenna 15cm aperture, >50dB of Gain 2. Waveguide Calibrator Insertion Loss < 2dB, Calibration Stability less than +/-2K 3. W-Band CMOS Synthesizer Bandwidth: GHz, Phase noise: 1MHz 4. 1 GHz CMOS Spectrometer Bandwidth: 1GHz, Dynamic range: >18dB, DC Power: <1W 17