PROBA-3 achieves a precise training flight

For the first time, two naves in orbit were aligned in millimeter precision and maintained their relative position for several hours without any control from land.

The ProBa-3 mission of the European space Agency has achieved its ambitious objective when its two spacecraft, the coronographer and the hidden, flew 150 meters away in perfect formation, simulating a single giant ship.

Earlier this year, the first step of the mission was successfully completed. The Operations team, formed by ESA engineers and its industrial partners who collaborate closely, met at the European Safety and Space Education Center on ESA in Redu, Belgium.

Using a set of positioning instruments, they were able to align the two ships in formation, and monitor them as they maintained their relatively autonomous position.

Now, after more adjustments and tests, the team has achieved the desired accuracy, turning Proba-3 into the first flight formation mission in the world.

The mission is based on several innovative technologies, many of which are technological demonstrations developed through the General Support Technology Program (GSTP) of ESA. “To do something that has never been done before, we needed to develop new technologies,” says Esther Bastida Pertegaz, TRUS-3 systems engineer.

“The formation flight is done when the ships are more than 50,000 km on the earth,” explains Raphael Rouoteot, proba-3 systems engineer.

“Here, the force of gravity of the earth is small enough, so it is needed very little propellant to maintain the formation. Then the formation breaks and must be acquired again in the next orbit, in a repeated cycle.”

The ultimate goal is for the two spacecraft to align with the sun so that the 1.4 -meter -size disk that the hidden wears project a 5 cm shadow on the optical instrument of the coronographer, which will allow it to study the faint solar crown.

Teodor Bozhanov, training systems engineer, explains later: «The beginning of this repetitive sequence of training flight is carried out by the ground control center, with the operations team obtaining position information to determine the exact location of the two satellites in space. Next, the propulsors of the mission are used to approach them.

«The rest is done autonomously. The spacecraft measures and controls its relative position using the Visual Based system, which includes a great angle camera in the hidden that tracks a set of intermittent LED lights in the coronograph.

“Once the satellites approach enough, a narrow angle chamber that is fixed in the same set of lights allows a more precise positioning.”

Raphael describes the last necessary step to close the precision gap: “Although we could previously make training flights using only the camera -based systems on board, we still lacked the desired precision.

«Two important achievements have been key to unlock it. First, it was the calibration of the laser instrument on board, and its integration into the full formation flying loop. “

“This laser instrument, called fine and longitudinal sensor (FLLS), allows a relative positioning to a millimeter precision,” adds Jorg Versuys, useful proba-3 manager. “It consists of a laser beam fired from the hidden spacecraft and reflected in the retroreflector of the coronographer back to the hidden, where it is detected.”

“The second crucial achievement was to successfully use the shadow position sensor,” continues Raphael. “An on -board algorithm based on the measurement of light intensity around the opening of the coronographer ensures that the coronographer’s spacecraft remains in the shadow projected by the hidden spacecraft.”

Esther points out: “Combining all these sensors, and thanks to on board software that manages all ship systems and provides navigation, guide and control functions, training is stable beyond expected.”

Damien Galano, Director of the PROBA-3 project, concludes: «We are talking about a millimeter accuracy in the range and submilimetric in the lateral position. We cannot wait to see the end of the calibration of the instrument and the first processed image of the Crown of the Sun “.

The PROBA-3 mission is led by ESA and carried out by a consortium led by the Spanish Sener, with the participation of more than 29 companies from 14 countries and with key contributions from GMV and Airbus Defense and Space in Spain and Redwire Space and Spacebel in Belgium.

The choronographer’s instrument comes from the Liege Space Center (CSL) of Belgium and scientific data will be prosecuted by the Royal Observatory of Belgium. The mission was launched on December 5, 2024 in a PSLV-XL launcher from the satisfied space center in Sriharikota, India.

Proba-3’s journey to see the Sun’s corona

Like

Thank you for liking

You have already liked this page, you can only like it once!