The honest truth is… there are precious few “science-y things” that would require a human on Mars. Our existing, proven chopper-, and rover- technology — all robotic and semi-autonomous — is a far smarter choice. The radiation and cold and lack of oxygen (and / or potable water) bother them… far less. It is a simple fact — despite what the world’s richest loon sez.

While doing it all remotely takes more iterative mission-time, it is far safer — for the human scientists / astronauts. In any event, here’s this excellent podcast, and its transcription into text, at NASA:

…[As an initial matter,] Mars at its furthest, is on the order of 250 million miles away from the Earth, or 1,000 times further into space than the Moon or a million times further into space than the space station. . . .

You land on Mars, now I got to wait for my launch window to come back from Earth, and that happens a year after I land, one Earth year, half a Mars’ year. So, you’re going to go halfway around the Sun on the planet Mars, and then your launch window opens so you can come back to Earth. So, once you have left Earth, and no spacecraft that we can possibly design has enough propellant on board to come back, once we’ve done that burn and headed off to Mars, you can’t abort and say, no, I don’t like this, I’m coming home. You’re committed. You’re committed to nine months out, you’re committed to a year on the surface, you’re committed to nine months back. Now we can mess with things and say, well, what if we do a special different trajectory and we’re going to come back and go closer to the Sun than the Earth and do a swing by the planet Venus and get a little boost from Venus’ current gravity and then we’ll come back to Earth a little earlier.

That adds complexity to your mission, now I got a have a bunch of heat shielding because I’m getting close to the Sun. And as with certain other philosophical conflicts in spaceflight, there has been a great deal of discussion and no winner on whether it’s better to just suck it up and do the long haul or try to be fancy and do this faster thing.

The pros and cons on both sides have not shown a clear victor on that one. So, basically, when you are committing to Mars, you’re committing to two and a half to three years away from the Earth and nothing important can break, nothing important can run out. All those engine burns have to work right and you have to launch yourself off a planet without help….

And all of the above is before we discuss how we’ve not solved the issue of protecting a crew from interstellar radiation, on those three or so years. Cancer, on return will be a likely scenario, for anyone going out that way. Damn. 2050 at the earliest is my guess — after we solve the shielding problems. Onward.

नमस्ते