1. 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

2. Spectral Profiles: 625 GHz
JEM/SMILES

3. Spectral Profiles: 650 GHz
JEM/SMILES

4. 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

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

6. View of SMILES
JEM/SMILES

7. 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

8. 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

9. 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:
23-26
Three HEMT Devices: FHX76LP
Gain:
30-33
JEM/SMILES

10. 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

11. 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

12. 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

13. SMILES Radio Spectrometer
Bandwidth:
1200 MHz x 2 units
IF: 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

14. 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