NASA Selects TESS, a "Follow-on" to Kepler

Following a three-year competition, NASA has selected the Transiting Exoplanet Survey Satellite (TESS) project at MIT for a planned launch in 2017. The space agency announced the mission — to be funded by a $200 million grant to the MIT-led team — this afternoon.

TESS team partners include the MIT Kavli Institute for Astrophysics and Space Research (MKI) and MIT Lincoln Laboratory; NASA’s Goddard Spaceflight Center; Orbital Sciences Corporation; NASA’s Ames Research Center; the Harvard-Smithsonian Center for Astrophysics; The Aerospace Corporation; and the Space Telescope Science Institute.

The project, led by principal investigator George Ricker, a senior research scientist at MKI, will use an array of wide-field cameras to perform an all-sky survey to discover transiting exoplanets, ranging from Earth-sized planets to gas giants, in orbit around the brightest stars in the sun’s neighborhood.

An exoplanet is a planet orbiting a star other than the sun; a transiting exoplanet is one that periodically eclipses its host star.

“TESS will carry out the first space-borne all-sky transit survey, covering 400 times as much sky as any previous mission,” Ricker says. “It will identify thousands of new planets in the solar neighborhood, with a special focus on planets comparable in size to the Earth.”

TESS relies upon a number of innovations developed by the MIT team over the past seven years. “For TESS, we were able to devise a special new ‘Goldilocks’ orbit for the spacecraft — one which is not too close, and not too far, from both the Earth and the moon,” Ricker says.

As a result, every two weeks TESS approaches close enough to the Earth for high data-downlink rates, while remaining above the planet’s harmful radiation belts. This special orbit will remain stable for decades, keeping TESS’s sensitive cameras in a very stable temperature range.

With TESS, it will be possible to study the masses, sizes, densities, orbits and atmospheres of a large cohort of small planets, including a sample of rocky worlds in the habitable zones of their host stars. TESS will provide prime targets for further characterization by the James Webb Space Telescope, as well as other large ground-based and space-based telescopes of the future.