Camera in Space to Capture the Impossible | Science

The team’s task was not an easy one. In recent months, Satlantis has been developing a camera to photograph the dark matter that exists in the universe. In fact, the 300-kilogram satellite carries four complementary high-precision instruments, two of them with infrared radiation. These cameras will observe the structures around small galaxies to study the distribution of this matter, which, by the way, is invisible.

The project is called ARRAKIHS (…

The team’s task was not an easy one. In recent months, Satlantis has been developing a camera to photograph the dark matter that exists in the universe. In fact, the 300-kilogram satellite carries four complementary high-precision instruments, two of them with infrared radiation. These cameras will observe the structures around small galaxies to study the distribution of this matter, which, by the way, is invisible.

The project is called ARRAKIHS (Analysis of resolved remnants of accreted galaxies as a key tool for halo studies). This is the first scientific mission of the European Space Agency (ESA) coordinated and led by Spain. It also has another peculiarity: “We are used to scientists defining the problem and then consulting with the industry. But in this case, we are hand in hand from the beginning,” explains Juan Tomás Hernani, founder and CEO of Satlantis, the company responsible for the central components of the satellite system – the so-called payload – and the development of the camera.

The company, based in Leioa (Bizkaia), is not starting from scratch. The firm has a decade of experience observing the Earth with these devices. For example, in detecting methane leaks or assessing the spectral signatures of fires. Now its cameras will rotate 180 degrees and focus on “nearby” galaxies located between 82 and 130 million light years away.

“We have to place the satellite far enough from the Earth so that the albedo light does not bother us. The chosen point is 800 kilometers from the surface, in a high orbit, so that we can adjust the rotation and always look at the same star, always with our back to the Sun,” the manager, who was previously Secretary of State for Innovation (2009-2012), describes in detail.

Camera resolution

The camera optics are “super-precise” thanks to lenses with a tolerance of one micron and a roughness of 40 nanometers. “If these same cameras were placed 500 kilometers from our planet to observe it, they would provide us with a resolution of 80 centimeters of a pixel. We would be able to recognize, for example, a car or fruit trees,” says Hernani.

Project Manager ARRAKIHS Carlos Corral van Damme of ESA adds that “the key to this precision will be planning”. From the agency’s satellite development centre in Holland, where it operates EL PAÍS, Van Damme explains that “the mission will have to accumulate 150 hours of observations in at least 75 nearby galaxies to study the structures in the halo with very low surface brightness”. The process would be more or less similar to what happens in a very long-exposure photograph, so that it is possible to “obtain a small number of photons”. Only in this case, we are talking about 900 exposures per galaxy, each lasting 10 minutes.

“The lack of knowledge about dark matter is equally surprising and worrying for the scientific community,” says the Belgian-born Spaniard. And also to his other mission mate, Rafael Guzmán, who has returned to Spain as the head of the consortium responsible for ARRAKIHS. after a three-decade professional career in California and Florida (USA). “Dark matter reflects the ignorance of what we don’t know yet about the Universe,” says Guzman.

Until now, science knows of its existence “because it reacts to the laws of gravity.” The astrophysicist, who is also a research professor at the Institute of Physics of Cantabria (IFCA), adds: “We cannot see it, but we can study the effect it has on elements made up of atoms or molecules.” In other words, these scientists will draw conclusions about the properties of dark matter based on its interactions with objects of ordinary matter.

If everything goes according to plan, they could get results that contradict empirical data. Currently, standard models of cold dark matter predict that galactic halos should have a much rougher structure than observed. “If they are right, 95% of the universe is in an unknown form and only 5% corresponds to all the planets, stars or galaxies that have been detected,” emphasizes Guzman. Likewise, dark matter would allow us to determine, firstly, the age of the universe and, secondly, its future, that is, “whether it will always expand or whether there will come a point when it collapses in on itself.”

The ARRAKIHS mission consortium currently consists of five countries. Switzerland and Sweden are mainly focused on the entire theoretical part, including the models whose predictions will be tested in this mission. The work of Austria and Belgium is related to the various instrument systems. The leadership of this entire work is entrusted to Spain. This international group consists of 120 specialists, divided into three areas: on the one hand, astrophysicists, physicists and mathematicians; on the other hand, a community of engineers from a wide range of fields; and finally, scientists and managers coordinating the work.

ARRAKIKH – part of one of the class missions. fast ESA. These tasks are characterized by a “low” budget and a maximum of 10 years between selection and launch, as the project manager points out. In fact, last March, an important milestone was reached: ESA approved the completion of Phase A, consisting of the verification of the photographic instruments.

The team is now working to complete Phase B in the first half of 2026. To do this, they will have to build prototypes of the equipment and test whether they will work in extreme thermosphere conditions, such as temperatures as low as 120°C below zero. The starting point is that Satlantis’ cameras have already been tested in space. The satellite is scheduled to launch in 2030.

Van Damme is also looking forward to this horizon, keeping an eye on the project reports. “The ESA budget allocated for ARRAQUICH “This is 200 million euros for the construction of the satellite and the preparation of the ground segment, the launch and operation of the mission,” he specifies. However, to this amount we will have to add the financing of the development of the instrument, “which is assumed by Spain and other countries,” and various “additional costs” that will be assumed by the other members of the consortium. For this reason, Van Damme hesitates to name a final figure, especially at this stage of the mission.

One thing is clear: “there is a clear desire for Spain to grow and be involved in the space sector.” For several years now, it has perceived “a more leading and active role in many missions, starting from a contribution in the field of leadership,” as in the case of ARRAQUICH.

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