Origins Space Telescope integration and testing

Abstract

I describe the plans, flows, key facilities, test beds, pathfinders, simulators, and ground support equipment that could be used to fully integrate, functionally test, and qualify the Origins Space Telescope (Origins). The Origins observatory consists of the spacecraft bus module and the cryogenic payload module, which comprises the telescope and three science instruments. The telescope is a three-mirror anastigmat and is composed of four mirrors: three with optical power (the elliptical primary, hyperbolic secondary, and elliptical tertiary mirrors) and a flat field-steering mirror. The three science instruments spanning the wavelength range 2.8 to 588 μm provide the powerful new spectroscopic and imaging capabilities required to achieve the scientific objectives. The Origins Survey Spectrometer uses six gratings in parallel to take multibeam spectra simultaneously across the 25-to 588-μm window through long slits enabling deep three-dimensional extragalactic surveys. The far-IR imager/polarimeter provides imaging and polarimetric measurement capabilities at 50 and 250 μm. Its fast mapping enables rapid follow-up of transient or variable sources and efficient monitoring campaigns. The mid-infrared spectrometer simultaneously provides spectroscopy over 2.8 to 20 μm with exquisite stability and precision (<5 ppm between 2.8 and 10 μm, <20 ppm between 11 to 20 μm). All the instruments are delivered for integration and test fully qualified and calibrated. The integration and test program implemented at each level of assembly is discussed as well as the separation of thermal vacuum testing between the hot and cold zones of the observatory. © 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.

Origins Space Telescope cryo-thermal system

“…With the simple, lightweight shields, Origins would be able to be tested in its flight configuration in an existing thermal vacuum chamber. 10 Thermal analysis shows that the design meets its targeted goals for temperature and heat loads and, simultaneously provides near isothermal conditions on sensitive surfaces independent of the pointing angle. Fig.…”

Origins Space Telescope: baseline mission concept

“…The Origins integration and test program 17 is shorter than JWST's Phase D, in part because Origins has very few deployable elements. Additionally, Origins has a Cryogenic Payload Module (CPM) comprising a cold shield, telescope, and instrument package, within which each assembly is isothermal.…”

“…A companion paper to this one describes design trades and the rationale for the STDT's choices. 8 This paper gives an overview of the Origins baseline mission concept, while parallel papers describe many different facets of the mission study: the scientific motivation for the mission and derived requirements; 9 the cryothermal system design and the attainability of the 4.5 K optical system operating temperature with current state-of-the-art cryocooler technology; 10 the telescope optical design and wavefront error budget; 11 materials trades, choices, and potential alternatives; 12 four scientific instruments [13][14][15][16] (one of which is optional and not included in the baseline mission concept); the integration and test program; 17 and key enabling technologies, notably cryocoolers, 18 mid-infrared detectors, 19 far-IR detectors, [19][20][21][22][23] and the far-IR detector readout system. 24 Earlier papers presented preliminary results of a stray-light analysis of the telescope 25 and a pupil densification technique that can be used to mitigate the effects of pointing jitter and enable extremely precise spectroscopic measurements of transiting exoplanets to search for planets with biosignatures in the mid-IR (2.8 to 25 μm).…”

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

“…Despite its shorter overall duration, the Origins I&T plan enables cryogenic testing at a higher level of assembly. 21 Finally, we adopted the JWST approach and allowed for primary mirror segment actuation (albeit in only three dimensions: tip, tilt, and piston), and chose thermally conducting materials for mirrors and metering structures 22 to minimize temperature gradients and ensure optical component and system-level performance compliant with a preliminary optical system error budget. 23 The telescope will be diffraction limited at 30 μm.…”