With the help of a gravitational assist from the Moon, the spacecraft will settle into a 13.7-day orbit around Earth, NASA said. Sixty days after the launch and following tests of its instruments, the satellite will begin its initial two-year mission. Four wide-field cameras will give TESS a field-of-view that covers 85 per cent of our entire sky.
Within this vast visual perspective, the sky has been divided into 26 sectors that TESS will observe one by one. The first year of observations will map the 13 sectors encompassing the southern sky, and the second year will map the 13 sectors of the northern sky. The spacecraft will be looking for a phenomenon known as a transit, where a planet passes in front of its star, causing a periodic and regular dip in the star’s brightness.
NASA’s Kepler spacecraft used the same method to spot more than 2,600 confirmed exoplanets, most of them orbiting faint stars 300 to 3,000 light-years away
“We learned from Kepler that there are more planets than stars in our sky, and now TESS will open our eyes to the variety of planets around some of the closest stars,” said Paul Hertz, Astrophysics Division Director at NASA Headquarters.
“TESS will cast a wider net than ever before for enigmatic worlds whose properties can be probed by NASA’s upcoming James Webb Space Telescope and other missions,” Hertz said. TESS will concentrate on stars less than 300 light-years away and 30 to 100 times brighter than Kepler’s targets, NASA said.
