The digital journal Progress in Earth and Planetary Science doesn’t even bother with “issues” anymore. Oh well, just posted in vol. 12, is:
Ulamec, S. Michel, P. Murdoch, N, et al. Science operation of IDEFIX, the MMX Phobos rover art. 97
s40645-025-00771-x
The journal had previously posted articles on elements of the IDEFIX program- now here’s the overall paper. Phobos, technically a “natural satellite of Mars”, is nevertheless a stand-in for small bodies. Because it is a small body; the only difference between Phobos, Deimos, and literal asteroids is that orbit state. Before Galileo or other asteroid missions, Viking and other results from Phobos/Deimos were our only up-close, resolved data at small bodies. Scientists used the two as proxies for literal asteroids for over a decade. Currently, one model for their origin is that Mars captured two passing asteroids.
Now, the MMX probe is under final assembly for its mission to the Martian system; its IDEFIX component has been completed. This Phobos rover is important as a tool for context and characterization of the MMX “landing” site; in engineering terms, anything that gets us more experience in small-body mobility puts humanity a step ahead. You can see the specifics of IDEFIX’s instrument array, and their implications and goals, at the individual articles I linked above.