Proba-3 lifted off on its PSLV-XL rocket from Satish Dhawan Space Centre in Sriharikota, India, on Thursday, 5 December, at 11:34 CET (10:34 GMT, 16:04 local time).
CREDIT: ISRO
This week, the European Space Agency's (ESA) latest space mission Proba-3 lifted off on a rocket from Satish Dhawan Space Centre in Sriharikota, India. At the heart of this mission are four tiny, cutting-edge silicon photomultipliers (SiPMs) from onsemi that - in a groundbreaking leap for space exploration – are set to create the first man-made solar eclipse in space. The historic mission will provide unprecedented insights into the sun's corona, the faint outer atmosphere usually obscured by the sun's intense light.
A Dance of Precision in Space
The Proba-3 mission features two satellites, the Coronagraph and the Occulter, flying for six hours at a time in perfect formation 150 meters apart. This alignment, maintained with millimeter precision while flying at a speed of 22,000 miles per hour, creates an almost perfect eclipse that allows scientists to study the sun's corona closer to the rim than ever before. The key to this extraordinary feat is the precise alignment technology enabled by onsemi's SiPMs. Without these sensors, achieving the same setup would require a physical 150-meter-long connection between the two satellites, which is not feasible due to space flight and payload constraints.
"ESA’s trust in onsemi's silicon photomultiplier technology is a testament to its unparalleled performance and reliability," said Dr. Steve Buckley, lead engineer for the Proba-3 mission at onsemi. “The Proba-3 satellite sensors provide stability and accuracy down to a millimeter, which enables the high precision formation flying required for creating a total eclipse. It's exciting to see this mission take flight and to see how far this technology has come in making ambitious space endeavors possible.”
The four onsemi SiPMs, known as Shadow Position Sensors (SPS), are housed in the camera of the Coronagraph satellite and measure the position of both satellites by tracking the shadow created by the Occulter disc on the Occulter satellite. This setup allows for an almost perfect eclipse, enabling the observation of the sun's corona with unparalleled clarity, which is impossible to achieve on Earth due to the diffraction pollution causes.
Why Study the Sun's Corona?
Studying the sun's corona is crucial because it provides insights into solar phenomena that significantly impact space weather and, consequently, Earth's technological infrastructure. The Proba-3 mission will deliver ultra-detailed images of the corona, which is the sun's faint outer atmosphere, usually obscured by the sun's intense light. By blocking out the sun's bright face, missions like Proba-3 can provide a rare and sustained view of the corona, allowing scientists to observe solar phenomena such as coronal mass ejections and solar winds. These phenomena can affect satellite operations, communication networks and power grids on Earth, making it essential to understand their behavior and origins.
A New Era of Space Exploration
The Proba-3 mission is not just a scientific endeavor; it is an engineering marvel and represents a new era of possibilities in space exploration. By providing the technology that makes this mission possible, onsemi is helping to unlock the secrets of the sun and pave the way for future missions that could revolutionize our understanding of the cosmos.
Damien Galano, ESA's Project Manager for Proba-3, added, "The Proba-3 mission is a significant milestone in space exploration. The precision and reliability of onsemi's sensors are critical to the success of this mission, and we are excited to see the groundbreaking data that will be collected".
A Journey of Innovation and Collaboration
Buckley, Systems Design Engineer at onsemi, has led the project, working closely with the Italian National Institute for Astrophysics (INAF) in Turin and other partners to ensure the success of the mission.
Over the past seven years, Dr. Buckley has been instrumental in getting the onsemi sensors ready for space. He was responsible for the design of the SPS electronics, the mounting of the SiPM sensors, the addition of filter films as well as the environmental and radiation testing of the sensors. This extensive process involved collaboration with specialist subcontractors and rigorous testing at various facilities, including the University of Louvain and the University of Liege, both in Belgium.
Dr. Buckley faced numerous challenges throughout the project. "The biggest challenge was finding the components that would give us the accuracy we needed to get that alignment with the stability accounting for the fact of the temperature changes, the atmosphere effects, noise, everything," Dr. Buckley explained.
Additionally, the onsemi sensors had to undergo extensive radiation assessments to ensure their performance would not degrade over time due to exposure to high levels of radiation in space.
Looking to the Future
As the Proba-3 mission prepared for launch, the excitement and anticipation at the launch site were palpable. A one-day delay due to a technical issue with the redundant propulsion system of the Coronograph spacecraft only heightened feelings of nervousness and enthusiasm, making it clear that there is more at stake here.
This mission is not just about studying the sun; it is about pushing the boundaries of what is possible in space exploration. And onsemi's SiPMs are part of creating a whole new world of possibilities, enabling scientists to see the sun in ways never before imagined and opening the door to future discoveries that could change our understanding of the universe.
No one could be happier about the successful launch than onsemi’s Dr. Buckley. “I still find it difficult to believe because I had it in my hands, but there you go.”
The first results from the mission are expected in about four months.
