The Habitable Worlds Observatory is a future NASA flagship observatory that will cover the ultraviolet, visible, and infrared wavelengths, as recommended by the Astro2020 decadal survey. This flagship general-purpose observatory will provide transformative observational capabilities, including the identification of Earth-like planets orbiting nearby stars and searching their atmospheres for signs of life, detailed characterization of objects in our own solar system, and tracking the cycling of matter in our universe. Across its science observations, the Habitable Worlds Observatory will broadly explore the story of life.

The Habitable Worlds Observatory architecture will build upon the success of the Hubble Space Telescope’s serviceability, James Webb Space Telescope’s segmented primary mirror, and the Nancy Grace Roman Space Telescope’s Coronagraph Instrument. Its segmented primary mirror will have an inner diameter of at least 6 m. However, the Habitable Worlds Observatory demands even greater performance than ever achieved before. The project’s goal from this early phase is to study initial bounding cases that can be used as the basis to form a baseline design for the preliminary design. The architecture trade space is explored with respect to science, engineering, and implementation.

Early analytic concepts for the Habitable Worlds Observatory were created to assess the science capabilities, scope architecture needs, develop modeling tools, evaluate the systems-level technical performance, and identify technology status. New technologies and testbed developments are underway to mature the readiness of key elements.

Papers are solicited in the following areas of interest:

• Architecture early analytic concepts
• Coronagraph system technologies
• Ultrastable telescope system technologies
• High-sensitivity UV and visible instrumentation 
• Integrated modeling, including technical and scientific performance
• Servicing

To submit a manuscript for consideration in the special section, please prepare the manuscript according to the journal guidelines and submit the paper via the online submission system. Once the special section is opened online, each paper will be published as soon as the copyedited and typeset proofs are approved by the author. A cover letter indicating that the submission is intended for this special section should be included with the paper. Manuscripts published in the Proceedings of SPIE are welcome for submission to this special section after proper revision to meet the standards of a journal publication. Submissions will be peer-reviewed in accordance with the journal's established policies and procedures.

*Manuscripts focused on science should discuss the science cases in the context of mission capabilities, requirements, or trade studies, to ensure the paper is of interest to the astronomical instrumentation community.

This special section follows from a workshop to be held at the Johns Hopkins Bloomberg Center in Washington, D.C., from May 5-7, 2025. The focus will be on addressing opportunities and challenges involved in doing science through infrared (IR) observation, the gaps and capabilities of infrared instrumentation and technologies, and the mission concepts necessary for achieving science objectives, in a variety of platforms, from balloons to probes and future flagship observatories.

Areas of interest include:
● Enabling technologies (detectors, optics, cryocoolers, materials, etc.)
● Modeling, simulations, and data analysis techniques and results
● IR instrumentation, including reviews*
● IR science cases for future missions**
● Mission concepts: all classes and all stages of development and deployment

This call is open to all members of the community as well as all workshop participants, including those who did not present their work at the workshop.

*Per journal guidelines, review papers must be coordinated with the JATIS editorial board ahead of submission. Please email jatis@spie.org to coordinate ideas for review papers for this special section with Editor-in-Chief Megan Eckart.

**Manuscripts focused on science should discuss the science cases in the context of mission capabilities, requirements, or trade studies, to ensure the paper is of interest to the astronomical instrumentation community.

To submit a manuscript for consideration in the special section, please prepare the manuscript according to the journal guidelines and submit the paper via the online submission system. Once the special section is opened online, each paper will be published as soon as the copyedited and typeset proofs are approved by the author. A cover letter indicating that the submission is intended for this special section should be included with the paper. Manuscripts published in the Proceedings of SPIE are welcome for submission to this special section after proper revision to meet the standards of a journal publication. Submissions will be peer-reviewed in accordance with the journal's established policies and procedures.

The X-ray Imaging and Spectroscopy Mission (XRISM) is a new X-ray observatory constructed under an international collaboration among JAXA, NASA, and ESA. It was launched on September 6, 2023, from the Tanegashima Space Center with an H-IIA rocket. The critical and commissioning phases were completed by early 2024, and scientific observations began as part of the performance verification phase. Scientific observations through the guest observer programs begin in August 2024.

XRISM has two scientific instruments with complementary features. One is Resolve, an X-ray microcalorimeter spectrometer with a large effective area, superb energy resolution above 2 keV, low background, and non-dispersive spectroscopy. The other is Xtend, an X-ray CCD imaging-spectrometer with a large field of view and moderate energy resolution. Their unique performances are being demonstrated by in-flight observations. Resolve will provide general observers from the community with high-resolution X-ray spectra from microcalorimeters for the first time. It will recover the opportunities lost by the early loss of the ASTRO-H “Hitomi” soft x-ray spectrometer (SXS) and of the Astro-E2 “Suzaku” x-ray spectrometer (XRS2). It will also be a harbinger of the Athena X-IFU, which is based on next-generation x-ray microcalorimeters.

This special section is intended to gather results obtained through the design, integration, operation, and calibration of the scientific instruments and the observatory. The purposes are two-fold: (1) to give comprehensive description of the instruments and the observatory so that guest observers can learn details for their observation planning and data analyses, (2) to share the results and lessons obtained on the ground and in orbit with the community, so that future missions are better designed, tested, operated, and calibrated.

To meet these objectives, we solicit contributions for the following topics.

• Instrument design, including sensor design, space cryogenics, and x-ray optics
• Structural, thermal, and optical performance models
• Integration, testing, calibration, and operations
• In-flight performance and findings
• Data analysis algorithms
• Instrument-related mission hardware and software systems
• Lessons and improvements for future applications

This special section focuses on technical aspects of XRISM and its instruments both on the ground and in the orbit. Astrophysical results from in-flight data are to be published elsewhere.

To submit a manuscript for consideration in the special section, please prepare the manuscript according to the journal guidelines and submit the paper via the online submission system. Once the special section is opened online, each paper will be published as soon as the copyedited and typeset proofs are approved by the author. A cover letter indicating that the submission is intended for this special section should be included with the paper. Manuscripts published in the Proceedings of SPIE are welcome for submission to this special section after proper revision to meet the standards of a journal publication. Submissions will be peer-reviewed in accordance with the journal's established policies and procedures.

The Probe Infrared Mission for Astrophysics ( PRIMA) is a proposed cryogenically cooled far-infrared (FIR) observatory submitted to NASA's 2023 call for Astrophysics Explorers (APEX) and planned to operate in the 2030s. With at least 75% of the planned observing time available for General Observer (GO) programs, PRIMA is responsive to all three science goals for a FIR probe, as described by the National Academy of Sciences Astronomy 2020 Decadal Survey: Tracing the astrochemical signatures of planet formation, probing the co-evolution of galaxies and their supermassive black holes across cosmic time, and measuring the formation and buildup of galaxies, heavy elements, and interstellar dust from the first galaxies to today.

With a 1.8 m telescope, cooled to 4.5 K, PRIMA promises orders of magnitude improvements in sensitivity and mapping speed compared to the previous generation of FIR observatories, enabling transformative science and opening ground-breaking new discovery space for a wide range of astrophysics investigations. In a Sun-Earth L2 orbit, PRIMA will have a field of regard of at least 26% of the sky at any given time. PRIMA is equipped with two science instruments, FIRESS and PRIMAger. FIRESS is a sensitive multimode survey spectrometer, operating at 24-235 micron, and with resolving powers from R~85 to thousands. PRIMAger is a versatile imager offering hyperspectral (R~10) imaging at 24-80 micron, and polarimetric mapping in four bands from 80-261 micron.

Papers are solicited for the following areas of interest:

• PRIMA instrumentation, design, thermal system design
• Enabling technologies
• Key FIR science cases and how they are addressed by PRIMA*
• PRIMA operations and community engagement

To submit a manuscript for consideration in the special section, please prepare the manuscript according to the journal guidelines (https://www.spiedigitallibrary.org/journals/journal-of-astronomical-telescopes-instruments-and-systems/author-guidelines) and submit the paper via the online submission system (https://jatis.msubmit.net/). Once the special section is opened online, each paper will be published as soon as the copyedited and typeset proofs are approved by the author. A cover letter indicating that the submission is intended for this special section should be included with the paper. Manuscripts published in the Proceedings of SPIE are welcome for submission to this special section after proper revision to meet the standards of a journal publication. Submissions will be peer-reviewed in accordance with the journal's established policies and procedures.

*Manuscripts focused on science should discuss the science cases in the context of mission capabilities, requirements, or trade studies, to ensure the paper is of interest to the astronomical instrumentation community.

This special section of JATIS focuses on addressing the opportunities and challenges involved in doing science through ultraviolet observation, the gaps and capabilities of ultraviolet instrumentation and technologies, and the mission concepts necessary for achieving science objectives, in a variety of platforms, from CubeSats to the next astrophysics flagship: the Habitable Worlds Observatory.

Areas of interest for this special section include:
● Enabling technologies (detectors, reflective coatings, gratings, filters, µ-shutters, etc.)
● Modeling, simulations, and data analysis techniques and results
● UV instrumentation, including reviews* (see note below)
● UV science cases for HWO and other classes of missions** (see note below)
● Mission concepts: all classes and in all stages of development and deployment

We envision a collection of peer reviewed papers that builds on work presented at the UV Science and Instrumentation Workshop, hosted at Jet Propulsion Laboratory, May 7-9, 2024. However, this call for papers encourages submission of workshop and non-workshop papers alike. Acceptance will be the result of peer review and will be independent of participation in the workshop.

To submit a manuscript for consideration in the special section, please prepare the manuscript according to the journal guidelines (https://www.spiedigitallibrary.org/journals/journal-of-astronomical-telescopes-instruments-and-systems/author-guidelines) and submit the paper via the online submission system (https://jatis.msubmit.net/). Once the special section is opened online, each paper will be published as soon as the copyedited and typeset proofs are approved by the author. A cover letter indicating that the submission is intended for this special section should be included with the paper. Manuscripts published in the Proceedings of SPIE are welcome for submission to this special section after proper revision to meet the standards of a journal publication. Submissions will be peer-reviewed in accordance with the journal's established policies and procedures.

*Per journal guidelines, review papers must be coordinated with the JATIS editorial board ahead of submission. Please email jatis@spie.org to coordinate ideas for review papers for this special section with Megan Eckart (editor in chief) and Shouleh Nikzad (JATIS associate editor and lead guest editor for the special section).

**Manuscripts focused on science should discuss the science cases in the context of mission capabilities, requirements, or trade studies, to ensure the paper is of interest to the astronomical instrumentation community.

The Roman Coronagraph Instrument, previously named the WFIRST-AFTA Coronagraph Instrument, is a technology demonstration that advances a range of new technologies, including advanced coronagraph occulters/masks, deformable mirrors, advanced wavefront sensing and control, and photon-counting detectors. Since the Special Section on WFIRST-AFTA Coronagraphs in 2016, the instrument has advanced and is now undergoing final flight integration and test. This work is highly relevant to the Habitable Worlds Observatory (HWO), given the need for high contrast coronagraphs that are capable of direct imaging of nearby Earth-like planets. HWO will benefit from Roman Coronagraph development not only in new technologies but also engineering and programmatic aspects. 

This special section calls for submission on Roman Coronagraph Instrument development and testing, including but not limited to: 

• Roman Coronagraph optical integration and test results
• Wavefront sensing (high order and low order) test results
• Coronagraph performance model validation
• EMCCD calibration and test results at instrument level
• Key active optical subsystems such as deformable mirror, fast steering mirror, focus control mirror, and precision alignment mechanisms
• Instrument electronics and software 
• Coronagraph opto-mechanical design and thermal controls
• Instrument operations
• Level 1 – Level 4 (L1 – L4) data processing pipelines
• Key ground support equipment
• Target selection and synergy with ground-based telescopes
• Lessons learned

To submit a manuscript for consideration in the special section, please prepare the manuscript according to the journal guidelines (https://www.spiedigitallibrary.org/journals/journal-of-astronomical-telescopes-instruments-and-systems/author-guidelines) and submit the paper via the online submission system (https://jatis.msubmit.net/). Once the special section is opened online, each paper will be published as soon as the copyedited and typeset proofs are approved by the author. A cover letter indicating that the submission is intended for this special section should be included with the paper. Manuscripts published in the Proceedings of SPIE are welcome for submission to this special section after proper revision to meet the standards of a journal publication. Submissions will be peer-reviewed in accordance with the journal's established policies and procedures.

The Arcus probe mission, proposed to the NASA Astrophysics Probe Explorer, addresses science prioritized by the Astro 2020 Decadal, including (i) exploring how supermassive black hole accretion and winds vary with luminosity, black hole mass, black hole spin, and other parameters, (ii) determining how gas, metals, and dust flow into, though, and out of galaxies, and (iii) probing stellar activity across all stellar types and lifecycles. The Arcus Probe mission provides a high-sensitivity soft X-ray spectrometer (XRS) with R~3500 (R>2500 req) and an average effective area in the 12-50Å bandpass of 335 cm2 (250 cm2 req). It will be complemented by a co-aligned UV spectrometer (UVS) working in the 1020-1560Å band with R= 24200 (R>17000 req) and >5× the sensitivity of the Far Ultraviolet Spectroscopic Observer (FUSE) at O VI (1020Å) that observes simultaneously with the X-ray instrument. The satellite will be in High Earth Orbit to enable long uninterrupted stares and a wide field of regard, with opportunities for fast response to targets of opportunity.

Papers highlighting the science opportunities, instrumentation, and operations of Arcus probe are solicited. Example areas of interest for this special section are:

• Mission design, including concept of operation considerations
• Instrument design, technology, and estimated performance
• Enabling technologies

To submit a manuscript for consideration in the special section, please prepare the manuscript according to the journal guidelines (https://www.spiedigitallibrary.org/journals/journal-of-astronomical-telescopes-instruments-and-systems/author-guidelines) and submit the paper via the online submission system (https://jatis.msubmit.net/). Once the special section is opened online, each paper will be published as soon as the copyedited and typeset proofs are approved by the author. A cover letter indicating that the submission is intended for this special section should be included with the paper. Manuscripts published in the Proceedings of SPIE are welcome for submission to this special section after proper revision to meet the standards of a journal publication. Submissions will be peer-reviewed in accordance with the journal's established policies and procedures.

This special section of JATIS focuses on addressing the challenges of making state-of-the-art measurements with imperfect detectors. As science objectives in astronomical sciences demand greater and greater fidelity and sensitivity, so too does the need for understanding and/or mitigating such imperfections.

This is a broad topic. Examples of the areas of interest for this special section include:

• New detector technologies including but not limited to:
  ○ narrow-gap semiconductor [e.g., IR] detectors;
  ○ CMOS;
  ○ Skipper;
  ○ MKIDs;
  ○ SNSPDs.
•  Software/algorithms for precision astronomy
  ○ Faint object characterization; image stacking
  ○ Point spread function retrieval or characterization
  ○ Astrometric retrieval
• Detector modeling
• Sensor and systematics characterization, including but not limited to:
  ○ narrow-gap semiconductor [e.g., IR] detectors;
  ○ CMOS detectors;
  ○ CCD detectors.

Addressing these topics, we envision a collection of peer reviewed papers that builds on work presented in Detectors for Astronomy & Cosmology, Parts 1 & 2 (JATIS, 2019-20). A number of these new papers will be work products of contributions presented at the Image Sensors for Precision Astronomy workshop, hosted at SLAC National Accelerator Laboratory, March 12-14, 2024. It is important to note, however, that this call for papers encourages submission of non-conference papers alike, since it is entirely independent of the workshop.

To submit a manuscript for consideration in the special section, please prepare the manuscript according to the journal guidelines and submit the paper via the online submission system. Once the special section is opened online, each paper will be published as soon as the copyedited and typeset proofs are approved by the author. A cover letter indicating that the submission is intended for this special section should be included with the paper. Manuscripts published in the Proceedings of SPIE are welcome for submission to this special section after proper revision to meet the standards of a journal publication. Submissions will be peer-reviewed in accordance with the journal's established policies and procedures.