MER missions maybetogether with other balloon explorers
..the original concept (as I remember it) was for instrument-laden balloons to float around large areas, doing imaging, radar, weather etc., then settling down to the surface at at night. The instruments (solar charge during the day) could then do surface studies until morning ..
The latest version is the Stratosail which suspends a stablising wing some miles below .. sounds already rather more complicated ..
