University of Iowa professor Don Gurnett is retiring after more than six decades of space research at the university as a student, professor and researcher, Radio Iowa reports. Gurnett taught undergrad and graduate-level classes for more than 50 years, published more than 700 papers and designed or built instruments for more than 35 space missions — including the Cassini mission to Saturn, the Juno mission to Jupiter and the Mars Express expedition. Despite retirement, Gurnett said he will continue to be funded by NASA to work on data returned by the Voyager 1 and 2 satellite missions, which have visited Jupiter, Saturn, Uranus and Neptune.