The issue is less that it’s the hardest to land on and more that it’s the hardest to get to, to arrive at and orbit. It takes less fuel to get to Pluto than it does Mercury.
As a matter of fact, yes! Tacking a sail side to side allows a sailboat to sail upwind in a zig zag pattern. With a solar sail, a spacecraft can tack away from the direction of orbit, slowing down to reduce its escape velocity, and allowing the Sun’s gravity to pull it closer. All using no fuel.
The issue is less that it’s the hardest to land on and more that it’s the hardest to get to, to arrive at and orbit. It takes less fuel to get to Pluto than it does Mercury.
Solar sails negate the need for fuel.
Can a solar sail get something from Earth to Mercury?
As a matter of fact, yes! Tacking a sail side to side allows a sailboat to sail upwind in a zig zag pattern. With a solar sail, a spacecraft can tack away from the direction of orbit, slowing down to reduce its escape velocity, and allowing the Sun’s gravity to pull it closer. All using no fuel.
Veritaseum breaks down the principle. https://youtu.be/jyQwgBAaBag