Optical design of the Origins Space Telescope

The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the universe today? How do habitable planets form? How common are life-bearing worlds? We describe how Origins was designed to answer these alluring questions. We discuss the key decisions taken by the Origins mission concept study team, the rationale for those choices, and how they led through an exploratory design process to the Origins baseline mission concept. To understand the concept solution space, we studied two distinct mission concepts and descoped the second concept, aiming to maximize science per dollar and hit a self-imposed cost target. We report on the study approach and describe the concept evolution. The resulting baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. The chosen architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch. The cryo-thermal system design leverages James Webb Space Telescope technology and experience. © 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.

Section: Focus On Cryo-thermal Designmentioning

confidence: 99%

Origins Space Telescope: trades and decisions leading to the baseline mission concept

Leisawitz

Amatucci

Allen

et al. 2021

“…A Lyot-coronagraph-based tip-tilt sensor (TTS) located in the instrument fore-optics uses the light reflected by a field stop, which corresponds to 0.3% of the light from the target, to send fine pointing information to the fine steering mirror (FSM) in the telescope optical train. 7 The TTS measures the long-term drift using the point source image formed on the focal plane through a Lyot stop and feeds this information back to the observatory to mitigate the longterm drift down to 2 mas over a timescale of a few hours.…”

Section: Misc-t Operation Principlementioning

confidence: 99%

Mid-infrared spectrometer and camera for the Origins Space Telescope

Sakon

Roellig

Ennico-Smith

et al. 2021

The mid-infrared spectrometer and camera transit spectrometer (MISC-T) is one of the three baseline instruments for Origins Space Telescope (Origins) and provides the capability to assess the habitability of nearby exoplanets and search for signs of life. MISC-T employs a densified pupil optical design, and HgCdTe and Si:As detector arrays. This optical design allows the instrument to be relatively insensitive to minor line-of-sight pointing drifts and telescope aberrations, and the detectors do not require a sub-Kelvin refrigerator. MISC-T has three science spectral channels that share the same field-of-view by means of beam splitters, and all channels are operated simultaneously to cover the full spectral range from 2.8 to 20 μm at once with exquisite stability and precision (<5 ppm between 2.8 to 11 μm, <20 ppm between 11 and 20 μm). A Lyot-coronagraph-based tip-tilt sensor located in the instrument fore-optics uses the light reflected by a field stop, which corresponds to 0.3% of the light from the target, to send fine pointing information to the field steering mirror in the Origins telescope. An additional MISC Wide Field Imager (WFI) is studied as an upscope option for the Origins. MISC-WFI offers a wide field imaging (3 0 × 3 0) and low-resolution spectroscopic capability with filters and gratingprisms (grisms) covering 5 to 28 μm. The imaging capability of the MISC-WFI will be used for general science objectives. The low-resolution spectroscopic capability in MISC-WFI with a resolving power R (¼ λ∕Δλ) of a few hundreds will be used to measure the mid-infrared dust features and ionic lines at z up to ∼1 in the Origins mission's Rise of Metals and Black Hole

“…Additional performance parameters are provided in Table 1, whereas optical parameters for the telescope can be found in Ref. 30. Figure 10 shows the unprecedented mapping efficiency FIP will provide.…”

Section: Photometric Survey Timementioning

confidence: 99%

Far-infrared imager and polarimeter for the Origins Space Telescope

Staguhn

Amatucci

Bradley

et al. 2021

The far-infrared imager and polarimeter (FIP) for the Origins Space Telescope (Origins) is a basic far-infrared imager and polarimeter. The camera will deliver continuum images and polarization measurements at 50 and 250 μm. Currently available detector technologies provide sufficient sensitivity for background limited observations from space, at least on a single pixel basis. FIP incorporates large next-generation superconducting detector arrays and our technology development plan will push the pixel numbers for the arrays to the required size of 8000. Two superconducting detector technologies are currently candidates for the instrument: transition edge sensors or microwave kinetic inductance devices. Using these detectors and taking advantage of the cryogenic telescope that is provided by Origins, FIP will achieve mapping speeds of up to eight orders of magnitude faster than what has been achieved by existing observatories. The science drivers for FIP include observations of solar system objects, dust properties, and magnetic field studies of the nearby interstellar medium, and large scale galaxy surveys to better constrain the star formation history of the universe to address one of the main themes of Origins: "How does the Universe work?" In addition to the science, the FIP instrument plays a critical functional role in aligning the mirrors during on orbit observatory commissioning. © 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.