SMILES: Superconducting Submillimeter-wave Limb-emission Sounder Mission Objectives Space Demonstration of Submillimeter Sensor Technology based on a Superconduvtive Mixer and 4-K Mechanical Cooler Experiments of Submillimeter Limb-Emission Sounding of the Atmosphere Global Observations of Trace Gases in the Stratosphere and Contribution to the Atmospheric Sciences JEM/SMILES

Spectral Profiles: 625 GHz JEM/SMILES

Spectral Profiles: 650 GHz JEM/SMILES

Global Coverage Trajectory for 24 Hours The Arctic Region Covered Latitudes: 68N – 35S (ISS Yaw: +15 deg) 65N – 38S (ISS Yaw: 0 deg) 61N – 42S (ISS Yaw: -15 deg) Horizontal Sampling Interval: about 360 km in orbital direction JEM/SMILES

Signal Flow Submm Signal is down-converted: => 11 - 13 GHz => 1.55 - 2.75 GHz Emission-line Spectra are derived by AOS (Acousto-optic Spectrometer). JEM/SMILES

View of SMILES JEM/SMILES

Receiver Sensitivity: SIS vs SBD SBD mixer receiver SIS mixer receiver hf/k: Quantum Limit Superconductive SIS mixer receivers have some 20 times higher sensitivity than conventional Schottky-diode mixer receivers for frequencies less than 700 GHz. JEM/SMILES

Developed by NASDA In-house activity. 640 GHz SIS Mixer Developed by NASDA In-house activity. Nb/AlOx/Nb Device: 1.2 um x 1.2 um, 5.5 kA/cm2 Fabricated at Nobeyama Radio Observatory JEM/SMILES

Cooled HEMT Amplifiers By Nitsuki Ltd. 20K-stage Amplifier 100K-stage　Amplifier Tphys = 300K Vd = 2V, Id = 10mA Tphys = 300K Vd = 2V, Id = 10mA Tphys = 100K Vd = 1V, Id = 5mA Tphys = 20K Vd = 1V, Id = 5mA Two HEMT Devices: FHX76LP Gain: 20-22 dB @300K 23-26 dB @20K Three HEMT Devices: FHX76LP Gain: 28-32 dB @300K 30-33 dB @100K JEM/SMILES

Sub-mm Receiver Subsystem To Antenna Ambient Temperature Optics Cryostat AOPT To Cold-Sky Terminator AAMP Single Sideband Filter Sub-mm LO Source CREC He Compressor (JT) He Compressor (ST) JEM/SMILES

Cryostat Radiation Shield: MLI (40 layers) Toyohashi, Jan. 6-7, 2000 Cryostat Radiation Shield: MLI (40 layers) Signal Input Window: IR Filters (‘Zitex’) Support for 100 K Stage: S2-GFRP Straps (12 pieces) Support for 20 K Stage: GFRP Pipes (4 pieces) Support for 4 K Stage: CFRP Pipes (4 pieces) JEM/SMILES

4-K Mechanical Cooler Cooling Capacity: 20 mW @ 4.5 K 200 mW @ 20 K Power Consumption: 300 W @ 120 VDC Mass: Cooler 40 kg Cryostat 26 kg Electronics 24 kg Total 90 kg Cooling to 4.5 K by Joule-Thomson Cooler Cooling to 100 K & 20 K by Two-stage Stirling Cooler JEM/SMILES

SMILES Radio Spectrometer Bandwidth: 1200 MHz x 2 units IF: 1.55 - 2.75 GHz / unit Focal Plane: 1728-ch. CCD array x 2 units Frequency Resolution: 1.8 MHz (FWHM) cf. Channel Separation: 0.8 MHz / ch. AD Conversion: 12-bit, 2-CCD readouts in 4.9 msec Adder Output: 16 bits x 1728 ch. x 2 units in 500 msec Acousto-Optic Spectrometer (Astrium & OPM) JEM/SMILES

ISS Environmental Issues Toyohashi, Jan. 6-7, 2000 ISS Environmental Issues Compatible Design Needed Deterioration of environmental vacuum may occur due to contamination. Measures needed to protect SMILES operation. Space Shuttle: Water Dumps JEM-PM: Cabin Air Vents Some EMI may deteriorate the data quality of SMILES, even if it is too low to damage the instruments. Most careful measures for EMI are indispensable. EM-shielding designs are adopted. JEM/SMILES