Mission-critical software development for a distributed and diverse user base

XTour is a distributed software system used to design operating commands for the Visual and Infrared Mapping Spectrometer (VIMS) instrument onboard the Cassini spacecraft. The distributed architecture increases security and accessibility by centralizing access to the large datasets of information required to create instrument commands. Users are able to leverage portable devices to connect to the server and quickly complete their tasks, independent of their location. In this paper we discuss the design and implementation of the XTour software.