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Lunar speed reentry is quite feasible, and has been practiced. Apollo did it fine, and Orion did it a few weeks ago. State of the art ablative shields, like the

Lunar speed reentry is quite feasible, and has been practiced. Apollo did it fine, and Orion did it a few weeks ago. State of the art ablative shields, like the PICA-X used on Stardust and Dragon, are quite capable of handling entry at Mars transfer speed. (Lunar entry profile is about 11km/s, Mars 13-14km/s--though it can go as high as 20km/s deformation on design.) The real problem with the return trip is getting off Mars. Specifically, putting enough propellant on the surface to get you back up. Sure, it's easier than Earth, but it's still a planet. If NASA were serious about Mars, they would be sending prototype ISRU plants every cycle, because having rocket fuel waiting for you on the surface is the real enabling technology for Mars exploration. Or Lunar or Venus for that matter.

brudgers 12y ago
It's not just getting fuel to Mars. It's building and operating launch infrastructure there. Unmanned LEO missions from KSC get delayed and fail. On Mars there won't be spare parts or separate ground crews, and the spacecraft will have to be readied having been through launch and touchdown cycles rather than a slow gentle roll from a VAB to launch pad. The speed of light means no real time support from Houston. If ten people go out, then ten people have to get an interplanetary space program established on Mars. It ain't gonna be a matter of pushing the easy button.