ARRAKIHS Mission
Fact Sheet
The mission
Science and Instrument
ARRAKIHS Consortium

Name: ARRAKIHS stands for “Analysis of Resolved Remnants of Accreted galaxies as a Key Instrument for Halo Surveys”. ARRAKIHS is a F-class mission to the European Space Agency (ESA) scientific program.
Mission Topic: Explore the ultra-low surface brightness local Universe to understand the nature of dark matter and to constrain the processes that rule the formation of galaxies (baryonic physics).
Mission Objective: ARRAKIHS aims to perform observational tests of the Λ-Cold Dark Matter (ΛCDM) model and break degeneracies with the effects of baryonic physics on galaxy formation, obtaining deep multi-band exposures of ultra-low surface brightness galaxies, and thus enabling detailed and systematic studies of extended galaxy haloes.
The observations will allow researchers to better understand the discrepancies between ΛCDM predictions and current observations and if these can be solved with a better understanding of the physical processes that govern galaxies formation.
Instrument and spacecraft: The instrument is a 4-channel simultaneous imager in the visible and near-infrared, optimized for low surface brightness observations. The single instrument will be mounted on a small satellite for a combined of 600 kg total wet mass.
Orbit: The ARRAKIHS mission will fly into a Low Earth Orbit (LEO) around 800km in a Sun-Synchronous Orbit (SSO) configuration between 650 and 800 km of altitude.
Survey duration: The nominal duration of the scientific operations will be of a total of 3 years. Covering approximately 100 square degrees.
Launch time: Planned by the end of 2030