Origins Space Telescope Mission Concept Study Report (1912.06213v2)

Abstract: The Origins Space Telescope (Origins) traces our cosmic history, from the formation of the first galaxies and the rise of metals to the development of habitable worlds and present-day life. Origins does this through exquisite sensitivity to infrared radiation from ions, atoms, molecules, dust, water vapor and ice, and observations of extra-solar planetary atmospheres, protoplanetary disks, and large-area extragalactic fields. Origins operates in the wavelength range 2.8 to 588 microns and is 1000 times more sensitive than its predecessors due to its large, cold (4.5 K) telescope and advanced instruments. Origins was one of four large missions studied by the community with support from NASA and industry in preparation for the 2020 Decadal Survey in Astrophysics. This is the final study report.

• The paper details an innovative telescope design featuring a 5.9-meter primary mirror and advanced cryogenic cooling for enhanced sensitivity.
• It employs mid-to-far infrared spectroscopy and imaging to map galaxy evolution and trace planetary formation with unprecedented precision.
• The study outlines strategic mission goals to characterize exoplanet atmospheres and detect biosignatures, paving the way for future explorations.

Essay on the Origins Space Telescope: Mission Concept and Scientific Prospects

The Origins Space Telescope (OST) represents an ambitious concept paper developed in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Sponsored by NASA, OST aims to revolutionize our understanding of the Universe across three primary astrophysics science goals: the workings of the Universe, the emergence of habitable conditions, and the prospects for life elsewhere. This essay provides an expert overview of the OST's design, scientific objectives, and the transformative potential of its advanced observational capabilities.

Mission Overview and Technical Design

The OST design features a single-aperture telescope with a 5.9-meter diameter primary mirror, a design decision prioritizing sensitivity and minimizing complexity compared to potential interferometer configurations. The telescope operates at a diffraction-limited capability at 30 μm, designed to function as a "light bucket" for shorter wavelengths. Utilizing mechanical cryocoolers and passive cooling through a two-layer sunshield, the telescope and instruments are maintained at an operational temperature of 4.5 Kelvins. This temperature is crucial to the mission's sensitivity goals, allowing the detection of faint signals from distant galaxies and exoplanetary systems.

The OST's architecture is characterized by a Spitzer-like configuration with components such as a single-stage 35 K radiator and a thermal arrangement to maximize isothermal conditions. The mission's sunshield design is simplified compared to the JWST, involving fewer deployments and thereby reducing potential risks.

Scientific Objectives and Instrumentation

OST is designed to achieve nine key scientific objectives over its mission lifetime by addressing questions of galaxy evolution, planetary system formation, and the conditions for life's emergence. Its suite of instruments allows for unprecedented mid-to-far infrared spectroscopy and imaging capabilities, targeting key astrophysical processes.

1. Galaxy Evolution: OST's Origins Survey Spectrometer (OSS) enables deep and wide spectroscopic mapping of galaxies, covering spectral features from 2.8 to 588 μm. With a thousand-fold improvement in sensitivity compared to previous missions, OST seeks to elucidate star formation rates, black hole accretion processes, and metal production from the epoch of reionization to the present.
2. Planetary System Formation: The Far-infrared Imager/Polarimeter (FIP) measures key emission lines such as the HD 112 μm line, offering insights into the gas masses of protoplanetary disks and tracing water abundance throughout the stages of star and planet formation.
3. Search for Life: The Mid-Infrared Spectrometer and Camera Transit (MISC-T) spectrometer targets atmospheric characterization of exoplanets, especially around M-dwarf stars. Through precise transmission and emission spectroscopy, OST aims to identify biosignatures and assess habitability indicators on potentially life-supporting worlds.

Scientific Impact and Future Implications

OST's scientific capabilities position it to make significant contributions across a broad range of astronomical phenomena. By filling the observational gap between JWST and ALMA, OST will provide crucial data for understanding the detailed interplay between star formation, black hole growth, and the interstellar medium in galaxies. In the context of planetary science, its sensitivity to far-infrared water transitions addresses the central puzzle of water's delivery to Earth and other habitable planets, critical for understanding the initial conditions for life.

The mission's focus on exoplanetary atmospheres, particularly around M-dwarfs, offers transformative potential for identifying planets with conditions conducive to life. Given the challenges faced by ground-based observations and the limitations of current space-based facilities, OST's observations are poised to provide a comprehensive understanding of exoplanetary climates and atmospheric compositions.

Conclusion

The Origins Space Telescope's mission concept and anticipated capabilities underscore its potential to address foundational questions in astrophysics and planetary science. Its innovative design and ambitious scientific objectives create a platform for discovery, promising to advance our understanding of cosmic evolution and the potential for life beyond Earth. As a true community observatory, OST is expected to foster groundbreaking advancements in the field, guided by peer-reviewed scientific priorities.

In summary, the OST represents a pivotal step forward in our pursuit of knowledge about the Universe and our place within it, contributing unparalleled insights into both the distant and nearby cosmos.