Probes travel to mars faster. They have lower mass to fuel ratios. A manned flight with water shielding for radiation. Rotating crew quarters to generate artif

Probes travel to mars faster. They have lower mass to fuel ratios. A manned flight with water shielding for radiation. Rotating crew quarters to generate artificial gravity. And other amenities necessary to support human life, will have far higher mass than a probe. It translates to travel time taking longer due to fuel consumption and storage being more limited.