NASA is designing a mission to explore Titan, the largest moon of Saturn. Titan has numerous hydrocarbon lakes containing a mix of liquid methane and liquid ethane in unknown proportions. As part of the mission, a small submersible vehicle will explore Kraken Mare, the largest of these lakes. Assuming the maximum depth of Kraken Mare is less than 400 meters [m], how much total pressure in units of atmospheres [atm] must the submersible be designed to withstand? Assume the surface pressure on Titan is 147 kilopascals [kPa], the surface temperature is 94 kelvins [K], and the gravity is 1.35 meters per second squared [ m/s2]. The specific gravity of liquid methane is 0.415 and the specific gravity of liquid ethane is 0.546.