percy is actually the first step in a plan to bring a martian surface sample to earth for the first time, which will be of huge massive scientific importance.

essentially a mini esa-built rover will collect the samples from percy and deliver them to a nasa-built rocket, which will launch into mars orbit and rendezvous with another esa-built spacecraft which will take the samples and return to earth by the year 2031 if all goes to plan (which it probably won’t).