In spaceflight there's a conflict between delta-V and thrust to weight ratio - solid rocket boosters give a lot of thrust or 'muscle' so they are used for getting things off the ground while the lighter fuels would be in a later smaller stage that thrusts to get you in transit from Earth to Mars.

Refueling could be a thing, but without space manufacturing it won't be much of a useful thing. The staged design we use will get you to the moon and back because blasting off from the moon isn't nearly as hard as blasting off from Earth.

Getting to Mars and back could hypothetically be done by parking a huge orbital fuel tank around Mars, but getting it there would be an unprecedented achievement. Payload is expensive and it takes a lot of heavy fuel to provide enough thrust for an earth->mars or mars->earth transit. If you want a human crew and a ship capable of holding them then the fuel tank is going to be ridiculous, and the heaviest stage to get it off earth's surface would be terrifying.