Overview and early results of the Superconducting Submillimeter‐Wave Limb‐Emission Sounder (SMILES)

TLDR

SMILES, a superconducting submillimeter limb‑emission sounder launched to the ISS on 25 September 2009, uses a 4 K mechanical cooler and superconducting mixers to observe 624–626 GHz and 649–650 GHz limb spectra, enabling retrieval of vertical profiles of middle‑atmosphere minor constituents such as O₃, HCl, ClO, HO₂, BrO, and HNO₃. SMILES demonstrated high potential for detecting middle‑atmosphere minor constituents, but its observations were suspended on 21 April 2010 after a critical component failed.

Abstract

The Superconducting Submillimeter‐Wave Limb‐Emission Sounder (SMILES) was successfully launched and attached to the Japanese Experiment Module (JEM) on the International Space Station (ISS) on 25 September 2009. It has been making atmospheric observations since 12 October 2009 with the aid of a 4 K mechanical cooler and superconducting mixers for submillimeter limb‐emission sounding in the frequency bands of 624.32–626.32 GHz and 649.12–650.32 GHz . On the basis of the observed spectra, the data processing has been retrieving vertical profiles for the atmospheric minor constituents in the middle atmosphere, such as O 3 with isotopes, HCl, ClO, HO 2 , BrO, and HNO 3 . Results from SMILES have demonstrated its high potential to observe atmospheric minor constituents in the middle atmosphere. Unfortunately, SMILES observations have been suspended since 21 April 2010 owing to the failure of a critical component.