CaSSIS data can be found in the ESA's Public Science Archive (PSA) here.
CaSSIS has three main science objectives
1. Image and analyze surface features possibly related to trace gas sources and sinks in order to better understand the broad range of processes that might be related to trace gases.
The science team will compile and prioritize a list of observation targets needed to test specific hypotheses concerning active surface processes on Mars. We will begin to address this objective early in the mission, prior to new trace-gas discoveries from EMTGO. Unusual or changing colors indicate active processes, perhaps linked to methane formation or release.
2. Map regions of trace gas origination as determined by other experiments to test hypotheses.
EMTGO experiments are designed to discover trace gases and study atmospheric dynamics to trace the gases back to their source regions (perhaps to tens of km). Once these discoveries are made (if that goal is realized), CaSSIS will place top priority on imaging these regions to formulate and test specific hypo-theses for the origin and/or release of trace gases.
3. Search for and help certify the safety of new candidate landing sites driven by EMTGO discoveries.
The discovery of methane has helped stimulate exploration plans in Europe and the U.S. A portion of NE Syrtis Major has recently been approved for priority MRO coverage as a candidate landing site for the Mars Science Laboratory; this site is at the margin of the Syrtis Major methane plume identified by Mumma et al. (2009). It is likely that the pair of NASA/ESA landers in 2019 will also consider methane areas for landing sites. At the workshop ‘Habitability and Landing Sites’ held in the UK (Cockell et al., 2009) the surfaces associated with methane plumes were identified as high priority exploration targets. However, the best locations will presumably be found by EMTGO, and MRO/HiRISE may or may not be able to certify new landing sites post 2017. CaSSIS cannot identify meter-scale hazards, but it can provide the 5 m scale slope information needed to complete certification of thousands of locations imaged by HiRISE, but not in stereo.
One Example of CaSSIS' capabilities
How does CaSSIS take images to produce digital terrain models (DTM)?
This short animation shows you the way images are acquired to produce DTMs in one pass over a target.