https://phys.org/news/2018-07-nasa-awards-drones-venus.html

In recent years, NASA has taken a renewed interest in Venus, thanks to climate models that have indicated that it (much like Mars) may have also had liquid water on its surface at one time. This would have likely consisted of a shallow ocean that covered much of the planet's surface roughly 2 billion years ago, before the planet suffered a runaway Greenhouse Effect that left it the hot and hellish world it is today.

In addition, a recent study – which included scientists from NASA's Ames Research Center and Jet Propulsion Laboratory – indicated that there could be microbial life in Venus' cloud tops. As such, there is considerable motivation to send aerial platforms to Venus that would be capable of studying Venus' cloud tops and determining if there are any traces of organic life or indications of the planet's past surface water there.