"If humanity doesn't land on Mars in my lifetime, I would be very disappointed.

Land on Mars, a round-trip ticket - half a million dollars. It can be done.
Land on Mars, a round-trip ticket - half a million dollars. It can be done.
Land on Mars, a round-trip ticket - half a million dollars. It can be done.
Land on Mars, a round-trip ticket - half a million dollars. It can be done.