In their first launch of a scientific satellite for NASA, SpaceX has placed the Transiting Exoplanet Satellite Surveyor (TESS) into Earth orbit and successfully recovered the first stage. TESS is a follow-on to the massively successful Kepler space observatory. Like Kepler, it will use the transit observation method to detect exoplanets, but unlike Kepler, it will be an all-sky survey, reliant upon an unusual orbit in a 2:1 resonance with the Moon (to avoid ever coming too close to the Moon and having the orbit disrupted). The orbit is completely outside the Van Allen Belts, with a period of 13.7 days. TESS will be able to downlink to ground stations during its perigees, at a distance of 108,000 km (about three times further away than the geosynchronous ring). Although TESS has a nominal primary mission duration of two years, this orbit is expected to remain stable for decades, and the spacecraft will almost certainly be used to destruction like so many other NASA spacecraft, finding mission extension after extension until there is nothing more that it can do.
Falcon 9’s upper stage performed two burns, and then released TESS in a supersynchronous transfer orbit; the satellite itself will finish refining the orbit. The upper stage has by now disposed of itself over the Pacific Ocean, and the payload fairing conducted a water landing as part of SpaceX’s effort to reuse the fairings. (The company only has one fairing-catcher ship, Mr Steve, which is currently in California, unavailable for this mission. So far, the closest a returning fairing has gotten to Mr Steve is a few hundred yards, so there is still some refinement needed.)