Van Kane offers up an informed look at the five finalists in NASA’s current cost-capped Discovery mission selection process. These are:

DAVINCI (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging) proposal to drop an instrumented probe into Venus’ atmosphere.
VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) mission to remap Venus’s surface with radar and conduct the first global mapping of its surface composition.
NEOCam (Near-Earth Object Camera) mission to launch the first space telescope dedicated to observing asteroids.
Lucy would study (flyby) the Trojan asteroids that share Jupiter’s orbit.
Psyche would orbit the asteroid 16-Psyche, which is unique among the larger asteroids in having a composition that appears to be largely metallic.

NASA will select one or two missions to actually fly in a year with launch to happen by the end of 2021.