Transiting Exoplanet Survey Satellite

Transiting Exoplanet Survey Satellite
Name	Transiting Exoplanet Survey Satellite
Mission type	Astrophysics, Planetary Science
Operator	NASA / MIT Kavli Institute for Astrophysics and Space Research
COSPAR id	2018-030A
Spacecraft	TESS spacecraft
Manufacturer	Orbital Sciences Corporation / SpaceX (launch provider)
Launch mass	361 kg
Payload mass	69 kg
Power	330 W
Launch date	2018-04-18
Launch site	Cape Canaveral Air Force Station
Orbit	13.7-day elliptical high-Earth orbit (2:1 lunar resonance)

Transiting Exoplanet Survey Satellite is a NASA-led space telescope mission designed to perform an all-sky survey for transiting exoplanets orbiting bright, nearby stars. Funded and managed by NASA with principal investigator teams at Massachusetts Institute of Technology Kavli Institute for Astrophysics and Space Research and built by industry partners, the mission uses wide-field CCD cameras to monitor stellar brightness and identify periodic dimming events indicative of planetary transits. The mission complements the discoveries of Kepler (spacecraft) and supports follow-up characterization by observatories such as Hubble Space Telescope, James Webb Space Telescope, and ground-based facilities including Keck Observatory and European Southern Observatory.

Overview

TESS conducts an all-sky photometric survey from a unique high-Earth orbit placed in a 2:1 resonance with the Moon to provide long, stable observing stares. The spacecraft carries four identical wide-field cameras derived from CCD technology developed for missions like Kepler (spacecraft) and instruments on Gaia (spacecraft). The survey strategy divides the celestial sphere into 26 sectors observed sequentially, prioritizing bright F, G, K, and M dwarfs to detect short- to medium-period transiting planets suitable for radial velocity confirmation with facilities such as HARPS, HIRES, and APF (Automated Planet Finder). Collaboration networks include teams at institutions like University of California, Berkeley, Smithsonian Astrophysical Observatory, and Space Telescope Science Institute.

Mission Objectives and Science Goals

Primary objectives include discovering transiting exoplanets around nearby bright stars to enable atmospheric characterization with follow-up instruments, expanding the sample of small planets analogous to Earth and super-Earths, and providing seed targets for transmission and emission spectroscopy by James Webb Space Telescope. Science goals emphasize measuring planet radii and orbital periods, enabling mass measurements through radial velocity campaigns at observatories like Subaru Telescope and Very Large Telescope, and informing occurrence rate studies previously advanced by Kepler (spacecraft). TESS also supports ancillary science such as stellar astrophysics, asteroseismology used by teams at Penn State University and University of Birmingham, and transient detection that benefits time-domain facilities like Zwicky Transient Facility and Large Synoptic Survey Telescope (now Vera C. Rubin Observatory).

Spacecraft and Instrumentation

The spacecraft bus integrates avionics, power systems, and attitude control hardware from aerospace contractors including Orbital Sciences Corporation and suppliers contracted through NASA Goddard Space Flight Center. The science payload comprises four 10.5 cm-aperture wide-field cameras coupled to custom CCD arrays produced by industry partners used previously on missions by Ball Aerospace and others. Onboard processors handle photometric extraction pipelines similar in concept to those developed for Kepler (spacecraft). Attitude control uses reaction wheels, star trackers, and a propulsion system derived from heritage components used on missions like Lucy (spacecraft) and Parker Solar Probe. Thermal design and radiation shielding draw on experience from Spitzer Space Telescope and Chandra X-ray Observatory heritage engineering.

Launch and Mission Timeline

TESS launched on 2018-04-18 aboard a Falcon 9 rocket operated by SpaceX from Cape Canaveral Air Force Station with a ride profile placing it into a highly elliptical transfer orbit followed by lunar gravity assists to settle into its final 13.7-day orbit. Primary mission operations spanned two years of full-sky coverage with extended mission phases approved to continue observations and deepen time baselines for selected sectors. Mission milestones include first-light images, detection of early planet candidates confirmed by spectroscopy at facilities like Las Cumbres Observatory Global Telescope Network and Gemini Observatory, and data releases curated by teams at MIT and archived in community repositories accessed by researchers at Caltech and NASA Ames Research Center.

Operations and Data Processing

Science operations and target selection involve collaborations between institutions such as MIT, NASA Ames Research Center, Space Telescope Science Institute, and international partners including European Space Agency affiliates. Raw CCD frames are downlinked to the Deep Space Network and processed through pipelines that perform calibration, aperture photometry, and transit-search algorithms adapted from those used by Kepler Science Center. Data products, target lists, and candidate catalogs are released periodically to the community, enabling follow-up by radial velocity teams at Observatoire de Genève and photometric validation by networks like KELT (Kilodegree Extremely Little Telescope). Citizen science platforms such as Planet Hunters and professional-amateur collaborations have participated in vetting time-domain events.

Discoveries and Scientific Impact

TESS has identified thousands of candidate transiting exoplanets and several confirmed systems spanning hot Jupiters to sub-Neptunes and terrestrial-sized planets around M dwarfs, including notable discoveries suitable for atmospheric study with James Webb Space Telescope and Hubble Space Telescope. These discoveries have refined occurrence rate estimates initiated by Kepler (spacecraft), informed formation theories developed by research groups at University of Chicago and Princeton University, and enabled comparative exoplanetology involving targets accessible to facilities like ALMA and SOFIA. The mission has catalyzed international follow-up campaigns, advanced asteroseismic studies of host stars, and contributed to the development of next-generation survey strategies pursued by projects at European Southern Observatory and the National Astronomical Observatory of Japan.

Category:NASA space telescopes