The Apollo Moon missions returned as little as possible to the Earth, to make the mission even feasible. That meant no fuel by the time you reach Earth’s atmosphere and a meteoric reentry starting at around 25,000 miles per hour, out in space. This was from a Lunar orbit with enough velocity that a portion of a LEM could reach it and sufficient fuel could be carried in the CSM for a return to Earth.
Mars would be very different. The velocity of anything that could reach the Earth from Mars’ higher orbit would be vastly higher. You don’t just take a cruise through space, you fall towards the Sun. It’s a long ways to fall and I haven’t heard a scientist say how fast you’d be going. I expect there’s not much grant money in saying it can’t be done, but I expect that aerobraking is out and that means way too much fuel dragged back from Mars.
I have always loved science, and I hate to see it abused just to give people paychecks. I think that this latest “mission” selected a rock for later return. What kind of sad joke is that? As if the hypothetical later mission couldn’t select its own rock.
Fake scientists, like Carl Sagan, have gotten fat spinning lies to keep the grant money flowing. First it was Perceval Lowell’s canals (at least it was his own money) and people were told of Barsoom and princesses. Then, it was just, maybe , “life” on Mars. Now, it’s fossil microbes. People should be able to figure out better when they’re being lied to.
I think that the trip to Mars is one-way. I don’t have a problem with that, but I expect that there’s not a lot of grant money for it.
And again, I remind you that like The Dude said, “yeah, well, you know, that's just, like, your opinion, man.”