How Do We Prepare a Spacecraft for Launch_ Countdown to T-Zero for NASA's TESS Mission

Revisit the April 18, 2018, launch of NASA's Transiting Exoplanet Survey Satellite (TESS) aboard a SpaceX Falcon 9 rocket. TESS is already scanning the skies, identifying planet candidates that may be orbiting distant stars. https://go.nasa.gov/2Q3J9ei

TESS is NASA's next step in the search for planets outside of our solar system, including those that could support life. The mission will find exoplanets that periodically block part of the light from their host stars, events called transits. TESS will survey 200,000 of the brightest stars near the sun to search for transiting exoplanets.