Despite encountering some hitches, NASA launched the Transiting Exoplanet Survey Satellite (TESS), with a SpaceX Falcon 9 rocket, sending the so-called “exoplanet hunter” to space on Wednesday, April 18. But with TESS now in space and people wondering what’s next, officials behind the project have opened up about what could be expected from the satellite going forward.
According to a report from Space.com that cited a number of TESS team members, including Orbital ATK spacecraft program manager Robert Lockwood, the first few days after launch will see TESS’s solar arrays deploying, before the satellite makes sure that everything is up to speed by performing system checks.
“First light” is expected to take place on April 26, eight days after TESS’s launch, as its science instrument is activated. NASA’s official TESS page lists this instrument’s features, which include four identical CCD cameras and a Data Handling Unit, or DHU.
TESS’s actual exoplanet hunting might not yield any immediate results, but its two-year mission will have the satellite monitoring over 200,000 stars and paying close attention to its brightness, specifically the so-called “transits” that take place when a small portion of sunlight gets blocked out by planets orbiting their host. This is the same phenomenon that NASA’s Kepler Space Telescope monitored, en route to its discovery of over 2,600 confirmed exoplanets since its 2009 launch. According to Space.com, TESS is expected to exceed that figure during the course of its mission.
Specifically, TESS’s exoplanet-hunting exploits might yield a total of 100 to 200 “approximately Earth-sized worlds,” and thousands more objects that might end up about as large as Jupiter, said TESS scientist Diana Dragomir, in an interview with EarthSky. Her colleague, TESS instrument manager Greg Berthiaume, offered more details on the type of exoplanet their team is looking for in particular — so-called “Earth analogs” that have similar features to our planet in terms of size, gravity, and potential habitability.
“That means we want to find planets with atmospheres, with gravity similar to Earth’s. We want to find planets that are cool enough so water can be liquid on their surfaces, and not so cold that the water is frozen all the time,” said Berthiaume.
— NASA_TESS (@NASA_TESS) April 18, 2018
The satellite’s orbit is also of great interest to observers, as TESS will be taking a “highly elliptical path,” orbiting Earth twice for each time the moon completes an orbit. Space.com wrote that this “very stable” orbit will ensure that the satellite will not have to make too many altitude corrections, as the moon’s gravity is expected to bring it back on course, should it significantly stray from its path. TESS is also likely to be safe from radiation and space debris, thanks to its steady orbit, which should be reached sometime in mid-June.
When it comes to its main purpose as an “exoplanet hunter,” TESS will be working in concert with ground and space telescopes alike, as astronomers hope to confirm any exoplanet candidates the satellite detects. All in all, TESS will likely cover about 85 percent of the sky through the duration of its mission, as NASA expects the satellite to spot its first exoplanets at some point in the current year.