Emily Chan
In 2013, the European Space Agency (ESA) launched the Gaia spacecraft to map the positions and movements of the stars in our galaxy. But in recent months, space weather has made it difficult for the satellite to do its job.
“Hyper-velocity space dust and the strongest solar storm in 20 years have threatened Gaia’s ability to carry out the precise measurements for which it is famous,” reported ESA officials.
A tiny particle traveling at high speed struck Gaia in April. The particle was smaller than a grain of sand. It is known as a micrometeoroid, and it left a hole in the spacecraft. Every day, millions of micrometeoroids burn up when they enter Earth’s atmosphere.
According to NASA, micrometeoroids travel at an average of 22,000 miles per hour. They often make contact with Gaia, but the spacecraft was built to withstand these impacts, so it has remained largely unaffected until now.
This time, the object collided with Gaia in such a way that it damaged the spacecraft’s protective cover. A little gap was created, which let in stray sunlight. Occasionally, Gaia’s extremely sensitive sensors would get disrupted.
While the engineers were trying to resolve that issue, another problem arose. Gaia has a “billion-pixel camera” that relies on 106 charged coupled devices (CCDs). These are sensors that turn light into electrical signals.
In May, the spacecraft experienced an electronics failure, causing one of the CCDs to stop working. Gaia has been in space for over a decade, and this is the first CCD issue it’s ever had. Each sensor has a specific function. The one that was affected was crucial for helping Gaia confirm the detection of stars.
“As a result, the spacecraft began generating a huge number of false detections that overwhelmed our systems,” said Edmund Serpell, a Gaia operations engineer.
Gaia usually sends 25 gigabytes of data to Earth each day. Without the software to eliminate false star detections, the amount of data received would be significantly higher.
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