Arrakihs, the first mission of the ESA Science Programme led by Spain, enters its development phase ahead of its launch in 2030

Arrakihs, the first mission of the European Space Agency (ESA) Science Programme led by Spain through the Ministry of Science, Innovation and Universities (MICIU) and the Spanish Space Agency (AEE), has confirmed today the start of its development phase ahead of its planned launch in 2030.

Arrakihs officially becomes the second F-class (Fast) mission, F2, of the ESA Science Programme, culminating a process that began with its selection in 2022. Fast missions are a category within the ESA Science Programme designed to be developed within shorter timeframes and with more contained costs than the Agency’s large-scale missions, allowing for a more agile response to new scientific challenges.

“With Arrakihs, we are placing Spain at the forefront of European space exploration,” said the Minister for Science, Innovation and Universities, Diana Morant. “It is a mission that generates knowledge, strengthens our business fabric, attracts talent and projects our country’s capabilities internationally,” the Minister added.

The research team responsible for Arrakihs is led by Rafael Guzmán, a research professor at the Institute of Physics of Cantabria (IFCA), a joint centre of the Spanish National Research Council (CSIC) and the University of Cantabria (UC). The Institute of Space Studies of Catalonia (IEEC — Institut d’Estudis Espacials de Catalunya), with researchers at the Institute of Space Sciences (ICE-CSIC), also plays a prominent role in the mission, leading the main instrument and contributing to the scientific aspect and the ground segment.

“It is extremely exciting to have confirmed that the mission will move forward with the IEEC/ICE-CSIC team, with whom we have collaborated on numerous scientific cosmology projects over the years,” explains Santiago Serrano (IEEC), deputy lead of the Arrakihs consortium and principal investigator of the instrument. He adds: “In Arrakihs, we are playing a key role from a scientific, technological and leadership perspective, contributing to having reached this point and to the challenges that lie ahead until the mission becomes a reality.”

“This is a major success for the IEEC/ICE-CSIC group, which plays a very important role in this mission,” agrees Pablo Fosalba, principal investigator of the group at ICE-CSIC and member of the IEEC. “Arrakihs will provide key information to understand how galaxies like the Milky Way form, as well as the nature of dark matter, one of the greatest mysteries of modern cosmology and fundamental physics,” the expert explained.

“Arrakihs is an innovative and unique galactic archaeology mission. By discovering galactic haloes that are difficult to observe, it will reveal new details about how galaxies form and whether the Milky Way is a unique case. Its rapid development highlights the flexibility and scope of the ESA Science Programme,” says Professor Carole Mundell, ESA Director of Science.

The mission was conceived to answer one of the great open questions of modern astrophysics: how galaxies form and evolve within dark matter haloes. To do this, it will observe, with unprecedented sensitivity, the diffuse, low surface brightness stellar haloes that surround galaxies like the Milky Way.

Arrakihs (an acronym for “Analysis of Resolved Remnants of Accreted galaxies as a Key Instrument for Halo Surveys”) will open a new window onto the so-called low surface brightness Universe, allowing the study of structures that until now remained practically hidden, and providing new clues about dark matter, galactic mergers and the evolution of galaxies.

Since its selection by ESA in 2022, Arrakihs has come through all the necessary stages to become a fully consolidated mission within the European Science Programme. During this period, the international consortium has completed the preliminary design of the satellite and its instruments, developed new cosmological simulations and galactic models, validated key technologies, and strengthened the mission’s scientific potential through increasingly deep observations of the low surface brightness universe.

The decision to adopt the mission, through which ESA authorises the transition from the design phase to the development and construction phase, has been approved by the member states meeting in the Science Programme Committee (SPC). This meeting was held between yesterday and today at the Instituto de Astrofísica de Canarias (Tenerife) under the chairship of Cecilia Hernández, Director of Programmes and Industry at the AEE.