Trevor Mahlmann

Most everyone reading this story will probably know that a SpaceX Falcon 9 rocket launched on Wednesday carrying a NASA spacecraft into orbit—the Transiting Exoplanet Survey Satellite—that will further the space agency’s mission of searching for exoplanets.

Less well known is the TESS spacecraft’s clever orbit, which will enable an on-a-budget but robust science mission of searching for planets transiting in front of nearby stars. This “lunar resonant” orbit, which has never been used by a spacecraft, will allow TESS to both observe nearby stars and transmit data back to Earth with a minimal energy expenditure. (The useful lifetime of a spacecraft is often determined by its amount of onboard propellant).