Prototyping ARRAKIHS: accelerating and derisking instrument development for an ESA fast-class mission

Fast-class missions in ESA’s science programme have as their main objective to nearly halve their development time
compared to medium or large-class missions; 8 years from selection to launch instead of 15. In the context of this
accelerated scheme, the development of bespoke high-performing instruments for space missions with attractive scientific
objectives is a considerable challenge.
Using the ARRAKIHS mission as an example we show how prototyping during the study phase helps accelerate and derisk
the development of such instruments. In this contribution, we first present the ARRAKIHS mission and the instrument
preliminary design, we then provide a summary of the outcome of more than 10 different prototyping activities from optics
to detectors, from electronic boards to mechanical parts which took place during phase B. We conclude with our main
lessons learned.