> that's already had 55 seconds of controlled flight Good. And once it makes the trip to Mars and lands successfully, with 100t of payload, then I will accept

> that's already had 55 seconds of controlled flight Good. And once it makes the trip to Mars and lands successfully, with 100t of payload, then I will accept it as an argument. > Parachutes, aerobraking, skycranes We are not talking about a 1025 kg science vehicle here, we are talking about 100t of cargo, that has to land in the same place, preferably intact. Good luck making a parachute that carries that weight in a 610 pascal atmosphere. And latest the colonists will have to land a ship there, or they are stuck. So no, without ships being able to land on Mars, intact, Mars Colony is not happening. And btw. since you mentioned Spaceship: I'm pretty sure landing the thing on mars and letting it take off from there, is what it says on their own website: https://www.spacex.com/human-spaceflight/mars/ https://www.spacex.com/human-spaceflight/mars/ (scroll down to the "TO MARS AND BACK" diagram) > they just need to set up enough that the arriving humans can do it relatively quickly (days). > We send pre-emptive missions to set things up (dig holes, set up solar panels, gather basic resources) Good, then show me that the robots can do that, under the conditions pointed out above. > I think we're just deeply divided on what we think ten thousand focused engineers with hundreds of billions of dollars in budget can accomplish in 10 years. No I don't think we are. I am well aware that nothing about a Mars colony is physically impossible, or outside the reach of contemporary human technology, if we really want to do it. I think it would take somewhat longer than 10 years, given the technological difficulties, but I don't think it is impossible. The thing where I think we disagree is, given all the problems I pointed out, whether or not it is worth it jumping through all those hoops just for...yeah, for what? For science? We have robots doing that on Mars, and they don't require habitats, or food, or water. Resources? Mars doesn't have any Earth doesn't already have in abundance. Land? The entire planet is an airless, freeze dried, irradiated, toxic wasteland. As a backup plan? Even after a thermonuclear war, Earth would still be more inhabitable than Mars. Wanna invest the time and effort of 10000 engineers and hundreds of billions of dollars working in international cooperation into space programs? Fine by me! Here are a few suggestions: - The DART test was a huge success, we should develop that, because defending earth from asteroids could come in handy at some point - A moon base sounds awesome. btw. the Moon might actually have a valuable resource we don't easily get on Earth: https://en.wikipedia.org/wiki/Helium-3#Moon - Please build more deep space telescopes - ISS is getting old - There is lots of garbage in LEO that we need a solution for - Eventually we will need much better propulsion systems All of these activities sound way better to me, than wasting resources trying to set up shop on a worthless ball of dust for no good reason.