NASA's Saturn exploration spacecraft, Cassini , has discovered an atmosphere about the moon Enceladus . This is the first such discovery by Cassini, other than Titan , of the presence of an atmosphere around a Saturn moon.
Cassini's main mission was something other than exploration
( z1 mission :ARG0 ( z2 spaceship :name ( z3 name :op "Cassini" ) ) :ARG1 ( z4 something :ARG2-of ( z5 except :ARG1 ( z6 explore :ARG0 z2 ) ) ) :mod ( z7 main ) )