Way back in 2013 NASA chose TESS as one of its future missions and it was originally pegged to launch past year.
The observatory is 4 feet across (1.2 meters), not counting the solar wings, which are folded for launch, and weighs just 800 pounds (362 kilograms).
Two hours before a scheduled liftoff, SpaceX on Monday postponed its planned launch of NASA's newest planet-hunting satellite.
SpaceX should go live with the YouTube video embedded below some 15 to 20 minutes before TESS's 6:32 p.m. EDT launch target on Monday.
There should be no issues with SpaceX being able to broadcast video from space as TESS is considered a public rather than commercial mission.
NASA's planet-hunting pioneer, the Kepler Space Telescope, has spent the past nine years focusing on considerably fainter, more distant stars and discovered almost three-quarters of the 3,700-plus exoplanets confirmed to date.
In a tweet, NASA said the problem lay in the rocket's guidance, navigation and control systems and would need a minimum of two days to resolve.
TESS is a scientific exploration to find exoplanets - worlds which orbit other stars - amongst 200,000 stars.
And because the planets circling them are bigger relative to the size of the star, and orbit at a closer distance, the slight disruptions of visible light from their transits are more pronounced, scientists said. The mission will focus on planets circling bright stars that are less than 300 light-years from Earth.
The Tess satellite will scan nearly the entire sky, staring at the brightest, closest stars in an effort to find any planets that might be encircling them.
It promises an ability to resolve the atmospheres of some of the new worlds, to look for gases that might hint at the presence of life. The teeny telescope will replace the Kepler/K2 mission, which has already discovered thousands of exoplanets.
"TESS is going to significantly build the number of planets that we need to consider", said Ricker. More than 3,700 exoplanets have been confirmed to date using a variety of techniques. "By looking at such a large section of the sky, this kind of stellar real estate, we open up the ability to cherry-pick the best stars for doing follow-up science", said Burt.
"One of the numerous stunning things that Kepler let us know is that planets are all over the place and there is a wide range of planets out there".