Portuguese companies involved in ESA’s mission to explore exoplanets

“It’s like a tailor’s job. We take the measurements, make the patterns and based on them we produce the ‘clothes’. Then we do a test to see if everything is all right. If it is, we proceed with the installation.” Miguel Santos makes the thorough work that has involved him and a team of six other people from the Portuguese FHP (Frezite High Performance) seem simple. The “clothes” are the thermal protections used in the optical telescope of Cheops (CHaracterising ExOPlanet Satellite), the satellite that ESA will send to space next Tuesday, December 17. These multilayer insulation (MLI) blankets, produced in Oporto, were afterwards installed on the satellite assembled in the centre of Airbus Space and Defense, on the outskirts of Madrid.

In ESA’s first-of-a-kind mission to study extra-solar planets, also known as exoplanets, FHP designed and produced the MLI blankets for the Optical Telescope Assembly (OTA), which includes, the radiator, the telescope structure and the optical bench. This MLI allows the telescope structure to withstand the extreme thermal amplitude of space, which varies between the high temperatures coming from the sun or the absolute zero (about -270 º C) on the opposite side to the sun.

“Electronics are susceptible to temperature, even the electronic components we use in everyday life cannot be subjected to high temperatures, and the MLI serve to maintain a comfortable environment for the equipment to work”. FHP (a 100% Portuguese company) has been working for ESA missions since 2007. They produced MLI of some of the instruments of the ExoMars TGO (Trade Gas Orbiter) and to the EDM (Entry, Descent and Landing Demonstrator Module)  which, says Miguel Santos, “has given the company a certain reputation in the segment of thermal coatings in our small universe”.

The company’s facilities in Oporto have a “clean room”, a bit like an operating theatre. “In hospitals, there’s a greater concern with bacteriological components; here we’re more concerned with particles. If a particle ends up in electronics this could lead to a short circuit or, if it ends up in the middle of a camera that’s photographing the stars, we won’t have the desired effect”, explains Miguel.

European cooperation

If finding exoplanets was far from a straightforward mission – the first was discovered only in the 1990s, three decades after Humans began to explore the space – its characterization, by measuring, defining shape, composition or orbital parameters –, is an even more significant challenge. Seeking to find out the conditions for the formation of a planet and potential appearance of life, ESA will launch the Cheops mini-satellite, which will be one of the secondary passengers of Soyuz-Fregat. The rocket will be propelled from the European spaceport in Kourou, French Guiana, at 9.45 a.m. CET (8.45 a.m., Lisbon time).  

The Spanish subsidiary of Airbus Defence and Space was responsible for the design of the spacecraft, while a consortium of 11 member states, led by Switzerland, in particular, the University of Bern, got the responsibility of delivering the essential elements of the mission. The mechanical structure was built in Switzerland, the focal plane assembly in Germany, the baffle in Belgium, the optical instruments in Italy, the data processing unit in Austria and the radiators in Hungary. Portugal, in addition to the work of the FHP team, was responsible for developing the mission planning software, which will enable satellite observations to be programmed.

Portuguese leadership

Cheops has as its primary objective the observation of bright stars that are already known to have exoplanets in their orbit. Equipped with instruments that allow high-precision monitoring of the brightness of each of these stars, the satellite will be used by scientists to look for signals indicating “traffic” as a planet passes through the face of the star, which will allow measuring the radius of the planets. In the case of worlds with a known mass, the astronomers will evaluate the density, looking for information on their internal structure.

Cheops will be on a mission of 3,5 years and, once launched into space, the satellite will observe the list of exoplanets defined by the mission’s scientific team, composed by researchers associated with the consortium, which will have access to 80% of the satellite’s observation time. The “optimal organisation” of all requests “so that the telescope can ensure the greatest possible number of observations throughout its useful life” is performed by the software developed by Institute of Astrophysics and Space Sciences and Deimos Engenharia.

“We have developed two of the most important components of the Cheops’ scientific centre, the main one being the planning system”, says Nuno Ávila, general director of Deimos Engenharia. This system “will collect all requests from the scientific community throughout the life of the satellite”, and is estimated that there will be between three and five thousand calls, which can range from observing a star at a specific time and date or monitoring a star for weeks, for example.

As Nuno Santos, who represents Portugal on the Board of Cheops’ mission, recalls scientists already know about 4,000 planets orbiting other stars. “We already know that the solar system is not unique in the universe, but there are many open questions”, he states. 

Nuno has been studying exoplanets for years, working so that humanity can “detect Earth-like planets orbiting other sun-like stars, studying in detail their composition, their atmosphere”. Eventually, he says, there will come the day when humanity “discovers another planet with signs of life”.

The AI astronomer states that the Institute entered Cheops’ mission “through scientific networking” achieved by its involvement in the creation of the Espresso spectrograph, an instrument installed in 2017 on the VLT (Very Large Telescope), which is known as the “next-generation planet hunter”.

Invited by the consortium for this new mission, the researcher reached out to Deimos Engenharia, as they are a reference in this area: “Together, we got the necessary funding to participate in the mission with a leadership role”.  In addition to the planning system, IA and Deimos developed the archive and system for data dissemination, and cataloguing of all the information that will be collected by the mission and that will be available to the current and future scientific community. They were also responsible for a significant part of the data reduction and analysis system.

Both Nuno Ávila and Nuno Santos reinforce the idea that the “knowledge that had been generated by multiple scientific missions of ESA and the Deimos-1 and Deimos-2 satellites”, was the base for the new system. The European Space Agency explains that was “necessary to use technologies that have already been tried and tested in space”,

with the fact that it is a class S mission (Small), with a smaller budget than usual and shorter deadlines. “The scientific community is used to solve their problems from scratch and in this way we have had numerous gains of efficiency”, says Nuno Ávila, reaffirming that “this has allowed cutting development times and mission costs to a minimum”. The fact that the satellite will be sent as a secondary passenger of Soyuz-Fregat, also conditioned several design details, according to ESA.

The Cheops’ scientific team also includes researchers Susana Barros, Sérgio Sousa and Olivier Demangeon, who are also researchers at the Institute of Astrophysics, which currently has a team of more than 20 researchers and PhD students working on exoplanets.

The Portuguese participation in the Cheops space mission ends with the presence of LusoSpace. The startup specialized in the space industry was responsible for the supply of two magnetometers – the system used to measure force and direction of the earth’s magnetic field – which will be used in satellite navigation.

The mission

• The first small mission of ESA’s science programme. The so-called S-Class missions have a more modest budget and a much shorter lead time than large or medium ones;
• An essential step in the characterization of planets with variable sizes between the Earth and Neptune;
• Evaluate the composition of minor exoplanets and how they have formed and evolved;
• Measure the dimensions of known exoplanets;
• Identify the best targets for future in-depth observations;
• Tailor-made to ensure a high scientific return with a small investment.

[Source: ESA]

Scientific topics to be addressed

• Focus on the study of bright stars that host exoplanets with a variable size between Earth and Neptune;
• Use of a high-precision photometer to accurately measure planets with a variable size between the Earth and Neptune;
• Associate the measuring instruments of Cheops with the know information about the mass of the planets to determine their composition and structure;
• Identify targets for research.

[Source: ESA]

Relevant data of the satellite

• Dimensions: 1,5×1,5×1,5m
• Launch mass (including propellant): 280 kg
• Download link: 1.2 GB of information per day.
• Cheops will be launched as a secondary passenger of the Soyuz-Fregat rocket from the European spaceport in Kourou, French Guiana.
• The rocket will put the satellite directly into helium-synchronous orbit where it will operate at an altitude of about 700 km. This orbit allows the ship’s rear to be permanently directed towards the Sun, ensuring a stable thermal environment, keeping sunlight at a minimum while the telescope is watching night targets in the opposite direction to the Sun.
• High-precision photometer equipment based on a 300mm effective aperture Ritchey-Chrétien telescope and a single CCD, operating on near infrared visible wavelengths (330 to 1100 nm).

[Source: ESA]

Launch:

December 17th, 9:45 am CET / 8:45 am lisbon time
Live streaming: esa.int/ESA_Multimedia/ESA_Web_TV