The missions are part of the Discovery Program and are intended to be "small" (by NASA standards) missions. They basically selected hardware that uses flight-p

The missions are part of the Discovery Program and are intended to be "small" (by NASA standards) missions. They basically selected hardware that uses flight-proven sensors and instruments derived from existing and flown hardware plus one delivered by the German space agency to minimise risks and costs. An airship would blow up the mission to a flagship-type mission, which wouldn't fit the program and would never be approved (especially in light of the utter disaster that both JWST [1] and NGRST aka WFIRST [2] turned out to be). I'm also happy for new Venus missions and I don't mind less ambitious missions at all - I'd rather have a successful "boring" orbiter and a basic atmospheric probe by 2030 than a grandiose proposal that maybe gets approved by 2025 and then launches in 2040 :) [1] https://en.wikipedia.org/wiki/James_Webb_Space_Telescope https://en.wikipedia.org/wiki/James_Webb_Space_Telescope [2] https://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telescope https://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telesc...