I asked a similar question a couple days ago over at reddit and got this reply: http://www.reddit.com/r/space/comments/3ag085/live_sources_of_nasaesa_imagery/cs

I asked a similar question a couple days ago over at reddit and got this reply: http://www.reddit.com/r/space/comments/3ag085/live_sources_of_nasaesa_imagery/csdretg http://www.reddit.com/r/space/comments/3ag085/live_sources_o... "Spacecraft data is downlinked to Earth as "telemetry packets" - basically big bundles of data formatted/compressed in such a way as to maximize the efficiency of transfer. There are typically separate science (e.g. images/data) and housekeeping (e.g spacecraft health, voltages, temperatures) telemetry packets. These data are nearly always "open" but we generally don't make them public because it's kinda meaningless. Instead, as soon as we receive the telem files, we unpack them and process them into useable data files. Most often these will be saved as FITS or HDF5 files and placed into a database for scientists to access immediately. At the same time - and where applicable - the data are also turned into jpg/png files that are placed on websites for the public and scientists to view. (For science analysis, we generally use the FITS/HDF5/etc data but we use the jpgs for general viewing) tl;dr Yes the raw data is generally available but formatted weirdly."