Let's do a quiz! The Japan-led Martian Moons eXploration (MMX) mission to Mars's moon Phobos will carry a rover named "IDEFIX" that was developed by the French and German space agencies. But what is the purpose of IDEFIX (in addition to other tasks)?
People. There is no way to sugarcoat this: You failed.
The answer was "Help the spacecraft land safely".
Samples from Phobos will be collected by the main MMX spacecraft, but landing is SUPER dangerous and no one has ever visited Phobos before, so WHAT IS DOWN THERE?
Thick sandy regolith? Sharp rocks? Mars rats that bite spacecraft toes?
UNKNOWN.
So the first job of IDEFIX is to be sacrificed to the Mars rats... uh, I mean... report back on the surface conditions.
In Japan, they describe the first to do a dangerous task as the "first penguin" 🐧
So, IDEFIX is the first penguin for Phobos!
The little rover is equipped with scientific instruments, so it will also return the first close-up analysis of the Phobos surface, several years before we can expect to get that sample back to Earth.
It will also explore the moon a little bit, but INCREDIBLY SLOWLY because the gravity is WEAK AND WEIRD with Mars being RIGHT THERE.
The MMX spacecraft does carry a radiation monitor that will be useful information for future crewed missions that may go to the Martian moons.
But IDEFIX is not designed to look for underground caves.
Exploring lava tubes has been proposed for future missions to our Moon. However, our Moon has a geological past that included volcanic activity that created lava tubes. Phobos is too squiffy for that, so I don't think we expect substantial caves.
@jannem Yes. (Other observations from orbit will also help select the landing site, but the rover data is particularly important because it's direct from the surface.)
@elizabethtasker - So...let me see if I have the science correct. If Phobos is anything like our own Moon, it is made of cheese, which would explain the presence of the rats. But wouldn't they have enough to eat as it is with all that cheese? What is the nutritional value of an extraterrestrial automated rover?? What is it that these rats want???