The site is down atm so I can’t check it out, so I’m going to do an educated guess.
JPL is NASA Jet Propulsion Lab. ASFAIK, and all their data is Public domain… People should be aware of them is it really is from NASA and not very new. What is needed is integration with OSM, which can be a bitch if ou don’t have huge stacks of disks and CPU.
Thus I believe that at least some JPL data are already well utilised and integration is not especially demanding. There may be other usable JPL data available in addition to global mosaic, though.
OSM used (way back) to include Landsat while editing on the website, but no longer does. So if there isn’t a tile server available I don’t think it’s practical to use any webserivce. WMS might be nice but it was VERY slow.