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Radiation damage to the Hubble Space Telescope has been several years out of phase with the Solar cycle
Authors:
Gavin Leroy,
Juan Paolo Lorenzo Gerardo Barrios,
Maximilian von Wietersheim-Kramsta,
Richard Massey,
Richard G. Hayes,
Jacob A. Kegerreis,
David Lagattuta,
Zane D. Lentz,
James W. Nightingale,
Jesper Skottfelt,
Felix Vecchi
Abstract:
As well as obtaining beautiful images of the Universe, the Hubble Space Telescope's CCD detectors are sensitive radiation dosimeters that have been monitored in Low Earth Orbit for more than 24 years. The rate of radiation damage they received has varied over each Solar cycle, but several years out of phase with the appearance of sunspots or coronal mass ejections. We investigate functional forms…
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As well as obtaining beautiful images of the Universe, the Hubble Space Telescope's CCD detectors are sensitive radiation dosimeters that have been monitored in Low Earth Orbit for more than 24 years. The rate of radiation damage they received has varied over each Solar cycle, but several years out of phase with the appearance of sunspots or coronal mass ejections. We investigate functional forms that successfully fit the time series of damage to telescopes elsewhere in the Solar system. We obtain remarkably accurate fits to Hubble data but with physically absurd parameter values. During image post-processing, such fits can be used empirically, to correct more than 99.5% of the radiation damage's effect on image quality. However, fits to the time series with physically reasonable parameters produce worse performance. Our results highlight the diversity of radiation environments in different parts of our Solar system, and the complexity of Low Earth Orbit in particular. Our results also motivate continued monitoring of radiation damage to currently operational spacecraft, to more reliably predict the rate of degradation in (and useful lifespan of) future missions.
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Submitted 18 August, 2026;
originally announced August 2026.
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Transformational astrophysics and exoplanet science with Habitable Worlds Observatory's High Resolution Imager
Authors:
Vincent Van Eylen,
Richard Massey,
Saeeda Awan,
Jo Bartlett,
Louisa Bradley,
Andrei Bubutanu,
Kan Chen,
Andrew Coates,
Mark Cropper,
Ross Dobson,
Fabiola Antonietta Gerosa,
Emery Grahill-Bland,
Leah Grant,
Daisuke Kawata,
Tom Kennedy,
Minjae Kim,
Adriana Adelina Mihailescu,
Jan-Peter Muller,
Georgios Nicolaou,
Mathew Page,
Paola Pinilla,
Louisa Preston,
Ted Pyne,
Hamish Reid,
Santiago Velez Salazar
, et al. (146 additional authors not shown)
Abstract:
Habitable Worlds Observatory (HWO) will be NASA's flagship space telescope of the 2040s, designed to search for life on other planets and to transform broad areas of astrophysics. NASA are seeking international partners, and the UK is well-placed to lead the design and construction of its imaging camera - which is likely to produce the mission's most visible public impact. Early participation in t…
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Habitable Worlds Observatory (HWO) will be NASA's flagship space telescope of the 2040s, designed to search for life on other planets and to transform broad areas of astrophysics. NASA are seeking international partners, and the UK is well-placed to lead the design and construction of its imaging camera - which is likely to produce the mission's most visible public impact. Early participation in the mission would return investment to UK industry, and bring generational leadership for the UK in space science, space technology, and astrophysics.
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Submitted 18 December, 2025;
originally announced December 2025.
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Radiation damage to the Hubble Space Telescope during two Solar cycles, and correction of Charge Transfer Inefficiency using ArCTIc
Authors:
Richard Massey,
Jacob A. Kegerreis,
Juan Paolo Lorenzo Gerardo Barrios,
James W. Nightingale,
Richard G. Hayes,
David Lagattuta,
Zane D. Lentz,
Gavin Leroy,
Jesper Skottfelt,
Felix Vecchi,
Maximilian von Wietersheim-Kramsta
Abstract:
From 2002 to 2025, the Hubble Space Telescope's Advanced Camera for Surveys has suffered in the harsh radiation environment above the protection of the Earth's atmosphere. We track the degradation of its image quality, as Solar protons and galactic cosmic rays have damaged its photosensitive charge-coupled device (CCD) imaging sensors. The rate of damage in low Earth orbit is modulated by…
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From 2002 to 2025, the Hubble Space Telescope's Advanced Camera for Surveys has suffered in the harsh radiation environment above the protection of the Earth's atmosphere. We track the degradation of its image quality, as Solar protons and galactic cosmic rays have damaged its photosensitive charge-coupled device (CCD) imaging sensors. The rate of damage in low Earth orbit is modulated by $18.5^{+4.5}_{-0.5}$ per cent during an 11 year Solar cycle, peaking $430^{+11}_{-5}$ days after Solar minimum as recorded in the number of sunspots. The type of damage is consistent with defects in the silicon lattice that have all stabilised into one of three configurations. We also present the open-source Algorithm for Charge Transfer Inefficiency correction (ArCTIc) v7. This models the (instantaneous or gradual) capture of photoelectrons into lattice defects, and their release after (a discrete set or continuum of) characteristic time delays, which creates spurious trailing in an image. Calibrated using the trailing of hot pixels, and applied during post-processing of astronomical images, ArCTIc can correct 99.5% of Charge Transfer Inefficiency trailing averaged over the camera's lifetime, and 99.9% of trailing in the worst-affected recent data.
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Submitted 2 December, 2025; v1 submitted 5 September, 2025;
originally announced September 2025.
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Euclid Quick Data Release (Q1): VIS processing and data products
Authors:
Euclid Collaboration,
H. J. McCracken,
K. Benson,
C. Dolding,
T. Flanet,
C. Grenet,
O. Herent,
P. Hudelot,
C. Laigle,
G. Leroy,
P. Liebing,
R. Massey,
S. Mottet,
R. Nakajima,
H. N. Nguyen-Kim,
J. W. Nightingale,
J. Skottfelt,
L. C. Smith,
F. Soldano,
E. Vilenius,
M. Wander,
M. von Wietersheim-Kramsta,
M. Akhlaghi,
H. Aussel,
S. Awan
, et al. (355 additional authors not shown)
Abstract:
This paper describes the VIS Processing Function (VIS PF) of the Euclid ground segment pipeline, which processes and calibrates raw data from the VIS camera. We present the algorithms used in each processing element, along with a description of the on-orbit performance of VIS PF, based on Performance Verification (PV) and Q1 data. We demonstrate that the principal performance metrics (image qualit…
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This paper describes the VIS Processing Function (VIS PF) of the Euclid ground segment pipeline, which processes and calibrates raw data from the VIS camera. We present the algorithms used in each processing element, along with a description of the on-orbit performance of VIS PF, based on Performance Verification (PV) and Q1 data. We demonstrate that the principal performance metrics (image quality, astrometric accuracy, photometric calibration) are within pre-launch specifications. The image-to-image photometric scatter is less than $0.8\%$, and absolute astrometric accuracy compared to Gaia is $5$ mas Image quality is stable over all Q1 images with a full width at half maximum (FWHM) of $0.\!^{\prime\prime}16$. The stacked images (combining four nominal and two short exposures) reach $I_\mathrm{E} = 25.6$ ($10σ$, measured as the variance of $1.\!^{\prime\prime}3$ diameter apertures). We also describe quality control metrics provided with each image, and an appendix provides a detailed description of the provided data products. The excellent quality of these images demonstrates the immense potential of Euclid VIS data for weak lensing. VIS data, covering most of the extragalactic sky, will provide a lasting high-resolution atlas of the Universe.
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Submitted 11 December, 2025; v1 submitted 19 March, 2025;
originally announced March 2025.