In 24 months, the Transiting Exoplanet Survey Satellite (Tess) should have sampled 85 percent of the heavens, taking in some 500,000 stars - many of which will be among the nearest and brightest in the sky.
TESS will concentrate on stars called red dwarfs, smaller, cooler and longer-lived than our sun.
The mission is called TESS, short for Transiting Exoplanet Survey Satellite, and it will spend two years scanning nearly the entire sky to search for alien worlds.
However, an issue with SpaceX's Falcon 9 rocket, which will blast off from Space Launch Complex 40 carrying NASA's planet-seeking spacecraft, has forced the company to scrub the first attempt to launch the TESS satellite. Of these, some 300 are expected to be Earth-sized and super-Earth-sized exoplanets, which are worlds no larger than twice the size of Earth.
Its powerful vision will have the capability to analyse the atmospheres of some of Tess's new worlds, to look for gases that might hint at the presence of life.More news: Unseasonal warmth in London for the Commonwealth Heads Meeting
"Transit photometry, which looks at how much light an object puts out at any given time, can tell researchers a lot about a planet".
"We can start to find out, how does planet occurrence vary as a function of the type of star and the age of the star?" Its main goal over the next two years is to scan more than 200,000 of the brightest stars for signs of planets circling them and causing a dip in brightness known as a transit.
"But since then, we have found thousands of planets orbiting others stars and we think all the stars in our galaxy must have their own family of planets". "TESS is kind of like a scout", said Natalia Guerrero, deputy manager of TESS Objects of Interest, an MIT-led effort that will catalogue objects captured in TESS data that may be potential exoplanets. After this list has been compiled, the TESS mission will conduct ground-based follow-up observations to confirm that the exoplanets candidates are true exoplanets and not false positives.
The Hubble Space Telescope and the James Webb Space Telescope, scheduled to launch in 2020, should be able to reveal more about planets' mass, density and the makeup of their atmosphere - all clues to habitability.
Disappointed space watchers were assured by NASA that there are no major concerns with the launch overall.