Due to bandwidth limitations, heavy processing of the high res images taken is made at space and only relevant results are sent back. Here is an interesting description of the new NASA's TESS mission (now that the Kepler mission is being phased out due to lack of fuel) that has the goal of finding new exoplanets:
https://arstechnica.com/science/2018/09/get-ready-for-a-flood-of-new-exoplanets-tess-has-already-spotted-two/
Quoting:
"TESS images a single area for roughly a month before moving on to the next. Over the course of a year, this will allow it to capture most of the sky in a single hemisphere; it will switch to the other hemisphere for its second year of observations. Should the hardware still be operational at the two-year mark, it will have imaged most of the sky, and a similar cycle will likely start again.
This cadence creates some trade offs. If a planet's orbit is such that it doesn't pass in front of its star during the month TESS happens to be pointing that way, we'll miss it (unless it's part of the small overlap between separate areas). This will bias us toward finding planets with short orbital periods, where a transit is guaranteed to happen whenever TESS gets around to pointing at it. Short enough orbits mean we can observe multiple transits during that month, confirming the planet's existence without the need for follow-on observations."
