Exo-S

Exo-S Exo-S was a proposed space telescope concept intended to directly image and characterize extrasolar planets, combining coronagraph technology with precision spacecraft design to study nearby stellar systems. The concept attracted attention from agencies, research institutions, and observatories seeking to follow up discoveries from missions and projects focused on exoplanets and high-contrast imaging.

Overview

Exo-S was conceived to advance high-contrast imaging techniques pioneered by missions and programs such as Hubble Space Telescope, James Webb Space Telescope, Kepler, Transiting Exoplanet Survey Satellite, and ground facilities including Very Large Telescope, Keck Observatory, and Subaru Telescope to observe targets discovered by surveys like Gaia and Wide-field Infrared Survey Explorer. The study leveraged heritage from technology development programs at NASA Goddard Space Flight Center, Jet Propulsion Laboratory, Lockheed Martin, and international partners such as European Space Agency and Canadian Space Agency, with advisory input from committees including National Academies panels and review boards associated with Astrophysics Decadal Survey processes. Exo-S aimed to complement concepts like WFIRST and proposals including HabEx and LUVOIR while building on coronagraph and wavefront control research supported by NASA Ames Research Center and programs at MIT, Caltech, Stanford University, and Princeton University.

Mission Concept and Design

The Exo-S design centered on a modest-aperture space telescope architecture similar in scale to instruments developed by Ball Aerospace and concepts studied by Northrop Grumman and Orbital Sciences Corporation that could host an internal coronagraph and precision pointing systems used in missions like Spitzer Space Telescope and Chandra X-ray Observatory. The concept incorporated spacecraft bus elements derived from missions such as Landsat, TESS, and spacecraft platforms flown by Aerospace Corporation partners, and envisaged collaborations with contractors experienced in cryogenic and thermal control systems, exemplified by projects at Lockheed Martin and Honeywell. Guidance, navigation, and control requirements referenced flight heritage from Mars Reconnaissance Orbiter, Cassini–Huygens, and formation-flying studies related to Starshade proposals that were explored with teams at Jet Propulsion Laboratory and NASA Jet Propulsion Laboratory.

Instruments and Technology

Primary instrument concepts included an internal coronagraph informed by laboratory demonstrations at National Institute of Standards and Technology, wavefront sensing and control hardware developed at Princeton Plasma Physics Laboratory and university laboratories such as University of Arizona and University of California, Santa Cruz, and detectors leveraging technology maturation at Raytheon Technologies and Teledyne Imaging Sensors. The instrument suite planned to employ deformable mirrors similar to those tested for WFIRST coronagraph technology demonstrations, spectral filters and integral field spectrographs drawing on designs from Gemini Observatory instruments and detector arrays used on Hubble Space Telescope instruments. Thermal and stability requirements referenced metrology and optical bench techniques developed at NASA Langley Research Center and facilities like JPL's High Contrast Imaging Testbed.

Science Objectives

Exo-S sought to image reflected starlight from nearby substellar and planetary companions identified by surveys including Kepler, TESS, Gaia, and radial-velocity programs conducted with instruments such as HARPS, HIRES, and ESPRESSO. Science goals ranged from characterizing atmospheric spectra and albedos to constraining orbital architectures of systems studied by observatories including ALMA, Arecibo Observatory, and Green Bank Observatory. Targets included nearby stellar types cataloged in datasets like Hipparcos and follow-up lists produced by teams at Harvard–Smithsonian Center for Astrophysics and European Southern Observatory. The mission aimed to contribute to comparative studies involving datasets from James Webb Space Telescope spectroscopic observations and future large-aperture mission concepts advocated in the Astrophysics Decadal Survey.

Development History and Status

The Exo-S concept evolved through community studies and technology assessments led by panels including participants from NASA Ames Research Center, Jet Propulsion Laboratory, Caltech, MIT, and industry partners such as Ball Aerospace and Lockheed Martin. It was evaluated alongside other mission concepts in community prioritization exercises driven by committees within the National Academies and input from international partners including European Space Agency and researchers at Max Planck Institute for Astronomy and Instituto de Astrofísica de Canarias. Technology maturation efforts included laboratory demonstrations supported by NASA Technology Development Programs and review workshops at institutions such as Space Telescope Science Institute and universities like University of California, Berkeley.

Launch and Operations Plan

Baseline planning considered launch vehicles and rideshare options offered by providers including United Launch Alliance, SpaceX, and international launchers like Arianespace variants, with orbit choices informed by precedents set by James Webb Space Telescope (L2 concepts), Hubble Space Telescope (low-Earth orbit operations), and other observatories. Mission operations concepts involved science teams and data centers modeled after operational frameworks at Space Telescope Science Institute, NASA Exoplanet Science Institute, and ground networks coordinated through facilities such as DSN and project offices at NASA Headquarters. Contingency and community access plans were envisioned to follow precedents established by archival policies of Hubble Space Telescope and cooperative programs run by European Space Agency and Canadian Space Agency.

Category:Proposed space telescopes