Easily changing the design and being the cheaper option to ASICs for small productions are the two main uses for FPGAs. You may be designing a box that can be c

Easily changing the design and being the cheaper option to ASICs for small productions are the two main uses for FPGAs. You may be designing a box that can be configured to do different things so you may want to support multiple FPGA images to switch back and forth depending on the mission. You may just want to be able to easily upgrade firmware for a complex design in the future. For Space DSP applications, the FPGA is king and will probably be for a long time simply due to the ability to cram a lot of functionality into a small space (DSP, microcontroller, combinational logic circuits, and massive I/O banks all in one chip)