Concept Study of the Heterodyne Spectroscopy Instrument (HSI) for the Proposed Far-IR Spectroscopy Space Telescope (FIRSST)
Abstract
The heterodyne spectroscopy instrument (HSI) is a focal plane array receiver (FPA) for the Far-IR Spectroscopy Space Telescope (FIRSST), a proposal submitted to NASA’s astrophysics probe explorer call. Though FIRSST was not selected for further study, the receiver design allowed us to quantitatively demonstrate that small (few to few tens of pixels) heterodyne FPAs are now feasible for space missions, that they can be built with high technology readiness level components, are reliable and fit within the mass/volume/power constraints of medium to large missions. The design also identified the challenges and critical design considerations, in particular great care needs to be taken to minimize the cryogenic heat load of the cryogenic IF amplifiers and to keep the power consumption of the spectrometer backends low. The HSI was designed primarily to study the trail of water from the interstellar medium to planets and to observe the important low-lying transitions of water and its isotopes between 500 and 2000 GHz undetectable from the ground due to Earth’s atmosphere. HSI has a spectral resolving power of up to 107 (0.03 km/s), ideal for kinematic studies or line tomography. HSI has six 5-pixel-arrays covering 3 frequency bands and 2 linear polarizations. The concept study showed that heterodyne array receivers such as HSI can be built today even for fast missions and that they are powerful and versatile instruments, with low-risk technology capable of opening up the THz sky at very high spectral resolving power for new discoveries
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BibTeX
@article{wiedner2026concept,
title = {{Concept Study of the Heterodyne Spectroscopy Instrument (HSI) for the Proposed Far-IR Spectroscopy Space Telescope (FIRSST)}},
author = {Martina C Wiedner and Andrey Baryshev and Paul Grimes and Victor Belitsky and Vincent Desmaris and Yan Delorme and Juan-Daniel Gallego and Cristina García-Miró and Uma Gorti and Paul Hartogh and Cornelia E Honingh and Bernd Klein and Jean-Michel Krieg and Gary Melnick and Sebastiano Ligori and Boon-Kok Tan and Bertrand Thomas and Volker Tolls and Jeanne Treuttel and Jérôme Valentin and David L Clements and Ray Blundell and Asantha Cooray and Meredith Macgregor and Ronald J Vervack},
journal = {IEEE Transactions on Terahertz Science and Technology},
year = {2026},
month = sep,
doi = {10.1109/tthz.2026.3671953},
url = {https://hal.science/hal-05732615v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Concept Study of the Heterodyne Spectroscopy Instrument (HSI) for the Proposed Far-IR Spectroscopy Space Telescope (FIRSST)
AU - Martina C Wiedner
AU - Andrey Baryshev
AU - Paul Grimes
AU - Victor Belitsky
AU - Vincent Desmaris
AU - Yan Delorme
AU - Juan-Daniel Gallego
AU - Cristina García-Miró
AU - Uma Gorti
AU - Paul Hartogh
AU - Cornelia E Honingh
AU - Bernd Klein
AU - Jean-Michel Krieg
AU - Gary Melnick
AU - Sebastiano Ligori
AU - Boon-Kok Tan
AU - Bertrand Thomas
AU - Volker Tolls
AU - Jeanne Treuttel
AU - Jérôme Valentin
AU - David L Clements
AU - Ray Blundell
AU - Asantha Cooray
AU - Meredith Macgregor
AU - Ronald J Vervack
PY - 2026
DA - 2026/09/10
JO - IEEE Transactions on Terahertz Science and Technology
DO - 10.1109/tthz.2026.3671953
UR - https://hal.science/hal-05732615v1
AB - The heterodyne spectroscopy instrument (HSI) is a focal plane array receiver (FPA) for the Far-IR Spectroscopy Space Telescope (FIRSST), a proposal submitted to NASA’s astrophysics probe explorer call. Though FIRSST was not selected for further study, the receiver design allowed us to quantitatively demonstrate that small (few to few tens of pixels) heterodyne FPAs are now feasible for space missions, that they can be built with high technology readiness level components, are reliable and fit within the mass/volume/power constraints of medium to large missions. The design also identified the challenges and critical design considerations, in particular great care needs to be taken to minimize the cryogenic heat load of the cryogenic IF amplifiers and to keep the power consumption of the spectrometer backends low. The HSI was designed primarily to study the trail of water from the interstellar medium to planets and to observe the important low-lying transitions of water and its isotopes between 500 and 2000 GHz undetectable from the ground due to Earth’s atmosphere. HSI has a spectral resolving power of up to 107 (0.03 km/s), ideal for kinematic studies or line tomography. HSI has six 5-pixel-arrays covering 3 frequency bands and 2 linear polarizations. The concept study showed that heterodyne array receivers such as HSI can be built today even for fast missions and that they are powerful and versatile instruments, with low-risk technology capable of opening up the THz sky at very high spectral resolving power for new discoveries
SN - 2156-342X
SN - 2156-3446
ER -