This week, the European Space Agency (ESA) and NASA signed a letter of intent to collect some soil samples from Mars and bring them back to the Earth. It is important to note that the said robotic mission is very preliminary as this is not an agreement to make this kind of mission happen. Instead, it is only considered as an initial step; the next is to examine the feasibility of such an endeavour and decide on if it is worth pursuing, which will happen next year.
If the said mission were to take place, it would occur in no less than three parts. First, soil samples from Mars would have to be prepared for the collection. Luckily, the said part of the mission will be relatively easy since the groundwork is in place already. The 2020 Mars rover of the agency is already equipped to collect some samples of Martian soil for later collection. Additionally, the ExoMars rover of ESA (set to land on Mars in 2021) will drill into the surface of the red planet and collect some samples.
The second part of the mission has not been designed yet. It is said to consist of some kind of lander and rover that could set down near one or both of these rovers. The said rover would then head out along the surface of Mars and collect the samples that are left behind, bringing the samples back to the lander. The ESA said that the lander would have some kind of small ascent vehicle attached which would then launch into orbit once all of the samples are already aboard it. This would be the first-ever rocket launch from Mars.
Finally, a spacecraft that is launched from the Earth would rendezvous with the ascent vehicle in orbit of the red planet and collect the samples. The said craft would then go back to Earth; once the spacecraft has landed, it would be placed into quarantine prior to being analyzed by the scientists.
It is considered to be an ambitious plan. However, considering that we probably are not getting humans to Mars anytime soon (at least, not through the help of NASA), it is a great way to explore the red planet without having to send humans to it. It will be exciting to see what NASA and the ESA say regarding the feasibility of the plan over the coming year.