The European Space Agency (ESA) awarded on September 15 a millionaire contract for the design, manufacture and testing of the mission Hera. It will be the first probe sent by humanity consisting of test the possibility of deviating the trajectory of a binary system from dangerous asteroids.

A strange object is approaching Earth at 22,000 kilometers per hour and could become a second mini moon

“He objective is to do an experiment so that in the event that an asteroid is at risk of colliding with the Earth, we are able to intercept it efficiently “account Jesús Gil 20 minutes away, Guidance, Navigation and Control Systems Engineer at ESA.

In the mission, approved last year during the ESA ministerial congress held in Seville, 17 member states of the agency participate, including Spain.

The contract worth 129.4 million euros was signed by the Director of Technology, Engineering and Quality of ESA, Franco Ongaro, Y Marco Fuchs, head of German aerospace OHB based in Bremen (Germany), prime contractor for the Hera consortium. The event took place at ESA’s European Space Operations Center, which will serve as the mission’s control center.

Baptized with the name of Hera in honor of the Greek goddess of marriage, it is, together with the Double Asteroid Redirection Test ship (DART) from NASA, from Europe’s contribution to an international planetary defense collaboration formed by European and US scientists called Asteroid Impact and Deflection Assessment, AIDA.

This near-Earth binary system, it is a system of two asteroids that orbit around a common center of mass, formed by Didymos, 780 meters in diameter orbited by a smaller one called Dimorphos, 160 meters. It has been chosen since it is prototypical of the thousands that suppose a impact risk for our planet.

“This is the more or less just size of the asteroids that can present a potential risk to the Earth” explains Gil.

Hera Mission Chart
Hera Mission Chart
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Name of the asteroids

Didymos which was first detected in 1996 by Joe Montani, from the Spacewatch project at the University of Arizona (United States), it was originally designated as a single object, which made it not meet the criteria for receiving a proper name. However, later, in 2003, while Petr Pravec, a planetary astronomer at the Ondrejov Observatory (Czech Republic), following the brightness of the unnamed asteroid, detected a pattern that indicated the possibility of a satellite orbiting the main object, Dimorphos.

The latter officially received its nickname in June 2020, a name chosen thinking that, in the future, it will be the first celestial body whose physical form will have been intentionally altered by human intervention, he explained. Kleomenis Tsiganis, planetary scientist at the Aristotle University of Thessaloniki (Greece).

Contribution of Spain

In order to carry out this mission on the Dimorphos satellite, Spain will develop the guidance, navigation and control system, “Very important for Hera because it will allow us to fly very close to the asteroid in order to have better science and reduce the work that the controllers have on the ground,” says Jesús Gil.

Moreover, the mission combines defense objectives of the Earth with other scientists and with technological experiments, which will be useful to future missions.

Furthermore, Hera will also deploy for the first time in deep space CubeSats Europeans, mini-satellites built from 10 cm on each side. In the CubeSat Juventas Spain will also make its contribution, providing a “gravimeter“in order to accurately measure the gravity of the asteroid, Gil says.

The mission will start with the dart launch (Double Asteroid Redirection Test) in 2021 that will impact Dimorphos a year later. The Hera probe is officially dated as launch in 2024, arriving at the asteroid two years later.

Mission Hera over the crater caused by the impact
Mission Hera over the crater caused by the impact
European Space Agency

In the trajectory there are various phases, “one of them very interesting, a flyover of the planet Mars“indicates Gil and continues” will give energy to the trajectory and also the possibility of doing some kind of complementary science“.

Finally, Hera will be able to study the crater left by the DART collision to know how effective it has been and to be able to extrapolate it to other future operations. Gil also explains that it is an operation with great importance as it is the first and points out: “at the scientific and Earth protection level, there are still many unknowns to be resolved.”