TESS

TESS
Name	Transiting Exoplanet Survey Satellite
Mission	Astrophysics Explorer
Operator	NASA
Launch	April 18, 2018
Launch vehicle	Falcon 9
Mass	362 kg
Orbit	High Earth elliptical (2:1 resonance with Moon)
Website	NASA TESS

TESS

The Transiting Exoplanet Survey Satellite is a NASA Astrophysics Explorer mission designed to perform an all-sky survey for exoplanets using the transit method. Developed by the Massachusetts Institute of Technology and managed by NASA's Goddard Space Flight Center, the mission builds on heritage from missions such as Kepler (spacecraft), Spitzer Space Telescope, Hubble Space Telescope and complements observatories including James Webb Space Telescope and Gaia (spacecraft). It targets bright, nearby stars to enable follow-up with facilities like Very Large Telescope, Keck Observatory, ALMA, and CHARA Array.

Overview

The mission concept was proposed in response to the NASA Small Explorer program and was selected through a competitive process involving institutions like MIT Lincoln Laboratory, Jet Propulsion Laboratory, Southwest Research Institute, and industry partners such as SpaceX. TESS conducts an all-sky photometric survey divided into sectors coordinated with ground-based efforts by observatories such as Las Cumbres Observatory, Harvard-Smithsonian Center for Astrophysics, and amateur networks linked to projects like AAVSO. The survey strategy leverages stellar catalogs produced by Hipparcos, Tycho-2 Catalogue, and Gaia DR2 to prioritize target lists for precision time-series photometry.

Mission and objectives

Primary objectives include discovering transiting exoplanets around bright, nearby dwarfs and characterizing planetary radii and orbital periods to enable mass and atmospheric follow-up. Science goals explicitly support studies parallel to those undertaken by Kepler (spacecraft) and follow-up synergy with James Webb Space Telescope, Hubble Space Telescope, Spitzer Space Telescope, and ground facilities including Keck Observatory, Magellan Telescopes, and Gemini Observatory. The mission also aims to produce catalogs useful to the exoplanet community, complementing surveys like Sloan Digital Sky Survey and contributing to target selection for projects such as PLATO (spacecraft) and the European Space Agency's exoplanet programs.

Spacecraft and instruments

The spacecraft bus was built by MIT with components from partners including Orbital Sciences Corporation and optics by teams with heritage from Kepler (spacecraft) and Spitzer Space Telescope. It carries four identical wide-field cameras with CCD focal planes designed for high-precision photometry across a broad visible bandpass. The instrument design adopted lessons from instruments such as MOST (satellite), CoRoT, and K2 mission to mitigate systematics, using thermal control strategies influenced by Hubble Space Telescope servicing experience. Onboard electronics and data handling systems were tested in collaboration with institutions like NASA Ames Research Center and Massachusetts Institute of Technology laboratories.

Operations and data processing

TESS operates in a unique high Earth elliptical orbit in 2:1 resonance with the Moon, enabling long, uninterrupted observations during each sector and stable pointing for weeks at a time. Science operations are managed through NASA Goddard Space Flight Center with scheduling and downlink operations coordinated via the Deep Space Network and partner ground stations including Malindi Space Centre and Canberra Deep Space Communications Complex. Raw cadence data are processed by the Science Processing Operations Center at MIT, producing calibrated light curves and transit candidate lists. Candidate vetting uses pipelines and tools developed with contributions from SETI Institute, Harvard-Smithsonian Center for Astrophysics, and community projects such as ExoFOP and Vanderbilt University collaborations. Public data releases follow models established by Kepler (spacecraft) and Gaia (spacecraft), enabling citizen science contributions through platforms like Zooniverse.

Discoveries and scientific impact

The mission has discovered thousands of exoplanet candidates spanning types from hot Jupiters to sub-Neptunes and Earth-sized objects around M-dwarfs. Notable confirmed systems include multi-planet architectures that have been studied with facilities such as Keck Observatory, Very Large Telescope, James Webb Space Telescope, and Spitzer Space Telescope for mass measurements and atmospheric characterization. TESS discoveries have informed formation and migration theories alongside work by researchers affiliated with University of California, Berkeley, Caltech, Harvard University, and Princeton University. The mission has also enabled stellar astrophysics advances including asteroseismology using techniques refined in studies with Kepler (spacecraft), stellar variability catalogs cross-matched with Gaia (spacecraft), and transient detections coordinated with surveys like Zwicky Transient Facility and Pan-STARRS. The dataset underpins exoplanet occurrence rate estimates that feed into strategic planning for missions such as LUVOIR and HabEx concepts.

Mission timeline and status

Selected in the early 2010s, the mission was funded and assembled through partnerships among NASA, MIT, and multiple contractors, launching aboard a SpaceX Falcon 9 from Cape Canaveral Space Force Station on April 18, 2018. Commissioning involved teams from NASA Goddard Space Flight Center and MIT and transitioned to routine science operations sector-by-sector. The mission has received extensions and continues to operate with coordinated follow-up campaigns involving observatories like Keck Observatory, Gemini Observatory, Las Cumbres Observatory, and space assets including James Webb Space Telescope and Hubble Space Telescope. Ongoing data releases and community follow-up ensure the mission remains a cornerstone of near-field exoplanet discovery and characterization.

Category:Space telescopes