On April 16, NASA is planning to launch its Transiting Exoplanet Survey Satellite, or TESS, on a SpaceX Falcon 9 rocket. TESS is an Earth-orbiting instrument meant to spot faraway planets circling some 200,000 stars within 300 light-years of Earth. Astronomers hopes that TESS will help them learn whether or not there are other habitable planets, or even life beyond the Solar System. TESS can’t do this alone, however.