We actually can send people to Mars. So why haven't we? First, with today's technology, it would be very expensive. We would need to use a lot of fuel to get there. And, once we arrived, unless we left again fairly soon, we would need to stay for nearly two years until the alignment of the planets allowed us the shortest journey back.
It also wouldn't be safe now. Space is hazardous because of radiation coming from the sun and galactic cosmic rays, which make us ill. We need to build a spaceship that can protect us from that. On top of that, without gravity, your heart muscle shrinks and your bone density and muscle mass reduce. Today, it would take eight months to get to Mars, enough time to damage your body, so we need to work out how to get there faster and protect the crew.
Visiting Mars one day will be wonderful. But we need to wait a few years and develop new technologies so we can do the Mars Mission cheaply, efficiently and safely.
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