Developed under Sener’s leadership, ESA’s Proba-3 mission successfully launched from India

The European Space Agency (ESA) Proba-3 mission was successfully launched on December 5th from the Satish Dhawan Space Centre, near Chennai, from a PSLV-XL launcher of the Indian Space Research Organisation (ISRO).

Proba-3 is a mission of special relevance for Spain, a country that leads the mission through the industrial engineering and technology group Sener, the main contractor, in close collaboration with a consortium of 40 companies from 16 countries. It is also a historic milestone for space exploration, as it will demonstrate that high-precision formation flight between satellites in space is possible; in addition to this technological objective, the mission has a scientific goal, as the synchronization between the two satellites that make up the mission (the Coronagraph and the Occulter) will allow the study of the solar corona in unprecedented detail, by creating an artificial eclipse.

The success of the mission will require millimetric precision when synchronising its two satellites, which will fly in an elliptical orbit, moving just over 60,000 km away from the Earth (approximately 10 times the distance from the surface to the Earth’s core). Another technical challenge posed by the project is the autonomy of the satellites: the formation will be managed automatically, with both satellites calculating their position and trajectory with respect to its counterpart, without the intervention of a human operator; to do so, they will use advanced guidance, navigation and control (GNC) systems, a branch of engineering that deals with the design of systems to control the movement of vehicles, both manned and autonomous, and in which Spain is a global leader.

The Coronagraph satellite will house the mission’s coronagraph, an instrument that will point directly at the Sun. The second satellite, the Occulter, will eclipse the Sun, interposing itself between the star and the Coronagraph. To do this, it will use a disc of about 140 centimetres in diameter and various devices (optical and laser) that will allow it to calculate the relative position and attitude between the two satellites and position them both with extreme precision.

The perfect synchrony between the two satellites will create an artificial eclipse in an unprecedented way: the coronagraph will be able to obtain images of the Sun that will not be affected by disturbances in the Earth’s atmosphere, while the Occulter satellite, hundreds of metres from the focal point of the optical instrument, will significantly reduce diffraction effects. Proba-3 will guarantee up to 1,000 hours of eclipses to study the solar corona in unprecedented detail.

New possibilities for space exploration

Precise formation flying will enable the satellites to act as a single optical instrument, composing a virtual structure in space with high reconfiguration capabilities. Proba-3 will demonstrate that future missions could be developed on a larger scale and at lower cost using multiple small modules that behave in flight as a single large satellite.

Proba-3 is the latest mission in a series of highly scientifically valuable projects, dating back to Proba-1, launched in 2001 (an Earth observation satellite with advanced onboard autonomy that incorporated an innovative hyperspectral instrument, operational for more than 20 years), as well as Proba-2 (launched in 2009 to observe the Sun, with more than 20 technological payloads and scientific instruments) and Proba-V (v for “vegetation”, launched in 2012, including innovative Earth imaging equipment, for global vegetation mapping using multispectral images).

Sener is the prime contractor for Proba-3 and is responsible for both the flight and ground segments, and the participation of the Spanish industry is completed by Airbus in Spain, which has carried out the design, manufacture and integration of the two platforms and cabling, as well as the delivery of on-board equipment on the two satellites; by GMV for the development of the formation flight subsystem, the relative GPS function and the flight dynamics calculation tool for operations; and by Deimos, responsible for the orbit analysis and the development of the rendezvous experiment. Thales Alenia Spain has delivered equipment on board the satellites.

In the words of Diego Rodríguez, Director of Space and Science at Sener: “Proba-3, the result of years of work and collaboration, is a technological milestone of great value for our industry and shows that Spain is capable of leading highly complex space missions. We want to thank all the professionals, participating companies and, of course, ESA, for their commitment and work, necessary to reach this moment.”

Proba-3 is part of the ESA General Support Technology Programme, and Spain’s participation has been possible thanks to the support of theMinistry of Science, Innovation and Universities, through the Spanish Space Agency, as well as close collaboration between companies at an international level.

Please find below the live broadcast via streaming from the ESA control centre in REDU (Belgium) produced by Sener with RedWire: