Habitable-Zone Exoplanet Observatory baseline 4-m telescope: systems-engineering design process and predicted structural thermal optical performance

Abstract

The Habitable-Zone Exoplanet Observatory Mission (HabEx) is one of four large missions under review for the 2020 astrophysics decadal survey. Its goal is to directly image and spectroscopically characterize planetary systems in the habitable zone around nearby Sun-like stars. In addition, HabEx will perform a broad range of general astrophysics science enabled by a 115-to 1700-nm spectral range and 3 × 3 arcminute field of view. Critical to achieving its science goals, HabEx requires a large, ultrastable UV/optical/near-IR telescope. Using sciencedriven systems engineering, HabEx specified its baseline telescope to be a 4-m off-axis, unobscured three-mirror anastigmatic architecture with diffraction-limited performance at 400 nm, and wavefront stability on the order of a few tens of picometers. We summarize the systems-engineering approach to the baseline telescope assembly's optomechanical design, including a discussion of how science requirements drive the telescope's specifications. We also present structural thermal optical performance analysis showing that the baseline telescope structure meets its specified tolerances. We report new and updated analysis that is not in the HabEx final report. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Concept of operations for the Neptune system mission Arcanum

“…Other space-based observatories were used as a reference to define the design requirements for the Somerville telescope. A science-driven design method, such as has previously been proposed [49] considering the observation of KBOs and Planet-Nine-like objects whilst orbiting Neptune, was used to define the requirements of the optical system.…”

Optical–Mechanical Integration Analysis and Validation of LiDAR Integrated Systems with a Small Field of View and High Repetition Frequency

“…Fitting Interpolation To date, this method has been applied to the design of optical instruments such as space optical instruments and large ground-based telescopes, and it is used to evaluate whether the optical performance of optical systems fulfills the requirements under the action of mechanical/thermal environmental loads [15][16][17][18][19][20]. The characteristics of the thermaloptical-mechanical elements in the Subarcsecond Telescope and BaLloon Experiment (STABLE) directly affect the quality of the point-spread function of the guide star on the detector, so a series of thermal, structural, and optical models were built to simulate system performance and ultimately inform the final pointing stability predictions [15].…”

“…The characteristics of the thermaloptical-mechanical elements in the Subarcsecond Telescope and BaLloon Experiment (STABLE) directly affect the quality of the point-spread function of the guide star on the detector, so a series of thermal, structural, and optical models were built to simulate system performance and ultimately inform the final pointing stability predictions [15]. During the development process of projects such as the Laser Interferometer Space Antenna (LISA) [16], Wide-Field Infrared Survey Telescope (WFIRST) [17], Narrow-Field Infrared Adaptive Optics System (NFIRAOS) [18], 4 m telescope for habitable exoplanet observation mission (HabEx) [19], and Advanced Terrain Laser Altimeter System (ATLAS) [20] in the ICESat-2 mission, an optical mechanical thermal integration analysis model was established, and the analysis results were validated for the system design.…”

Optimization of Thermal Control Design for Aerial Reflective Opto-Mechanical Structure

“…The absolute temperatures of the opto-mechanical structure and envelope are T os and T en , respectively. Denoting the radiation area of the opto-mechanical structure by A os , the radiation power Q os rad from the opto-mechanical structure to the envelope can be estimated as [15] Q os rad = A os ε os σ T 4 os − T 4 en (5) In Formula (5), σ = 5.67 × 10 −8 W (m 2 •K 4 ) is the Stefan-Boltzmann constant. Obviously, the higher the value of T en , the less heat the opto-mechanical structure loses through radiation.…”

“…To improve the ability to clearly image distant targets, it is necessary to have a larger aperture for the primary mirror and secondary mirror, while ensuring a minimal wavefront error (WFE) on the reflective surface [5]. The WFE is impacted by the manufacturing and assembly technology and also varies with environmental factors [6,7].…”