Technical Challenges of Mars Landing

I didn't realize how difficult this would be.

But mention sending a human mission to land on the Red Planet, with payloads several factors larger than an unmanned spacecraft and the trepidation among that same group grows even larger. Why?

Nobody knows how to do it.

Surprised? Most people are, says Rob Manning the Chief Engineer for the Mars Exploration Directorate and presently the only person who has led teams to land three robotic spacecraft successfully on the surface of Mars.

“It turns out that most people aren’t aware of this problem and very few have worried about the details of how you get something very heavy safely to the surface of Mars,” said Manning.

He believes many people immediately come to the conclusion that landing humans on Mars should be easy. After all, humans have landed successfully on the Moon and we can land our human-carrying vehicles from space to Earth. And since Mars falls between the Earth and the Moon in size, and also in the amount of atmosphere it has then the middle ground of Mars should be easy.

Airbags are out; too many Gs for astronauts. Powered rocket landings like the lunar lander are out because they are unstable in an atmosphere. Parachutes don't work because they won't have time to work. Heat shields are out because they don't have time as the atmosphere is too thin to have enough drag. It;s the worst of all worlds.