Mars has quickly become a place of interest in our solar system. Humankind has already sent a bevy of landers, orbiters, and rovers exploring the planet's surface, but it may finally be time to take the next significant step in planetary research: sample return.
Indeed, planetary scientists on Earth are foaming at the mouth for genuine Martian surface samples, and a future NASA mission could realize this plan and push Mars-centric research forward.
NASA's Mars 2020 rover will include a state-of-the-art sample collection system, but it will leave any samples it collects on the Martian surface until we're ready to grab them. Then again, when will that be? A good question.
NASA has a few ideas encompassing how we might be able to recover these samples, but most are still imaginative at this point. This video goes over some of the multi-stage systems that have been conceptualized.