#39 re ability to leave Mars. Haven’t you seen the Movies “Mission to Mars” (I think it had Michael Madsen and Val Kilmer and Cary Ann Moss, and another like it with Don Cheadle who does leave Mars by other means?
Seriously, due to Mars lighter gravity, space ships could be assembled from parts shipments on the planet, fuel added, and Voila, you’re homeward bound, not that we would want any Martian Marxists coming back to wreck earth a second time.
There is a huge, yawning gulf between the physical possible and available technology.
Regardless, Hollywood notwithstanding, the economic hurdles are enormous.
BTW, Mars gravity is less than half the problem. The problem isn’t just Mars gravity, it’s the earth and sun’s a gravity. After falling downhill from Mars’ orbit to Earth’s orbit and getting an addition and significant tug from Earth’s gravitational field, you need a lot of braking to slow up and not hurdle past earth and back to the orbit of Mars, or burn up on reentry into the Earth’s atmosphere. The specific kinetic energy associated with the fall from Mars to Earth more than 8X that from the Moon to Earth.
BTW, Mars gravity is less than half the problem. The problem isn’t just Mars gravity, it’s the earth and sun’s a gravity. After falling downhill from Mars’ orbit to Earth’s orbit and getting an addition and significant tug from Earth’s gravitational field, you need a lot of braking to slow up and not hurdle past earth and back to the orbit of Mars, or burn up on reentry into the Earth’s atmosphere. The specific kinetic energy associated with the fall from Mars to Earth more than 8X that from the Moon to Earth.