[frankenMonkey]

"The technology to bring humans from Mars back to Earth simply does not exist yet."

ugh.... I think it's the exact same technology used to get there, just pointed in a different direction.

Or is that the story they're telling the volunteers so they don't expect a ride home? Yeah, that's the ticket!

[Lonesome in Massachussets]

I think it's the exact same technology used to get there, just pointed in a different direction.

It's not that easy. You need almost as much fuel to return from Mars as to get there. The payload to (fuel + overhead) ratio for a trip to Mars is horrendous. There is no booster or staging system that exists today that could take anyone from earth to Mars and back. Those Mars Rover gizmos do not have the overhead of keeping human beings alive and we have absolutely zero chance of bringing them back. The whole idea is a non-starter.

[newzjunkey]

The knowledge exists but the machinery/equipment does not thus the technology doesn’t really exist. We know “how” in principle except the weather on Mars is more inhospitable than Earth but we haven’t designed or built a way to do it.