Food heating concepts were investigated as part of the International Space Station Galley development effort, which culminated in testing the Conduction Oven Tray proof of concept prototype.
The first step of the investigation was to determine what heating concepts best suited the myriad of requirements imposed on the Galley Food Heating System (FHS). Major FHS requirements include power limits, daily energy limits, waste heat limits, the ability to heat frozen and ambient foods, and the ability to accommodate variable food package geometries. The review of microwave, convection, conduction, radiation (or light or infrared), steam, and combination oven types with respect to the ISS Galley application are detailed in an Oven Performance Matrix.
Results presented in the Oven Performance Matrix show the top three oven type candidates are conduction oven, convection oven, and conduction/convection oven combination. Conduction oven attributes leading to its number one ranking include high reliability, excellent food temperature control, ease of use, minimal noise, EMI compliance and peak power requirement. The convection oven scored similar to the conduction oven but ranked second due to its relatively higher noise level, higher EMI potential, lower reliability, and increased peak power and daily energy usage.
In addition to the FHS requirements, the Proof of Concept Conduction Oven was designed to perform an experiment investigating heating of frozen foods. In particular, frozen food heating times were measured with respect to varying oven plate temperatures and food package to oven plate heat transfer contact area. Test data is also presented showing that the Proof of Concept oven successfully heats ambient food within the thirty minute requirement. Finally, ISS Galley FHS forward work is presented in this paper along with further detail on the oven type trade study, Proof of Concept design and testing, and frozen food experimental investigation test results.