Abstract: A system includes a top cycle and a bottoming cycle. The top cycle is an engine having a combustor. The combustor receives a fuel. The combustor is capable of igniting a mix of fuel and a gas, and creating products of combustion. Products of the combustion pass downstream through a first heat exchanger. The bottoming cycle has a bottoming cycle working fluid receiving a first amount of heat through the first heat exchanger. The bottoming cycle produces work from the first amount of heat. The bottoming cycle working fluid then passes through a second heat exchanger and rejects a second lesser amount of heat. A source housing fuel is delivered to the combustor via the second heat exchanger. The bottoming cycle working fluid provides heat to the fuel being delivered to the combustor. The source is configured to maintain the fuel at a temperature equal to or below 0° F.