Why Mars Is Hard

Mars sits at minimum 55 million km from Earth. A one-way trip takes 7 to 9 months. Communication delay reaches 24 minutes each way, so astronauts cannot rely on real-time ground support and must be fully self-sufficient.

The biggest health risk is radiation. Outside Earth's magnetic field, cosmic rays deliver roughly 1 sievert over a round trip, significantly raising cancer risk. Shielding adds weight — and weight is the enemy of every mission.