I you were to do this the rockets would collapse down generating massive heat causing the rockets to explode however due to its density being about 4.5g/cm^3 its gravity is to high and over time the water and CO2 from the combustion would form a atmosphere over our metallic Saturn held close to the surface due to the massive gravity and because Saturn did not change in mass the moons and rings would be unaffected the water would form pools as over millions of years solar wind blows the atmosphere away due to the lack of a magnetic field but the water would be held on due to the gravity and eventually as it radiates the heat from the explosion away the surface would freeze over into strange forms of ice due to the pressure from the gravity