The European Space Agency’s Gaia probe was damaged by a micrometeoroid and a solar storm, which temporarily disrupted its operations. Despite serious damage, scientists report that the probe has returned to normal operation after a particularly dangerous incident. We were dealing with a truly incredible case – it is rare that at almost the same time (for space conditions) a probe had to deal with both a micrometeoroid and the effects of a solar storm.
Gaia orbits more than 1.5 million kilometers from Earth, in the so-called Lagrange point, where the gravity of Earth and the Sun combine to create a stable orbit. The probe’s mission is to create a three-dimensional map of the stars in the Milky Way.
In April, a micrometeoroid smaller than a grain of sand (such objects move incredibly fast and behave like super-fast projectiles) hit Gaia, damaging its shield protecting its instruments. ESA reported that light from the Sun penetrating the gap disrupted the sensors. In May, another failure occurred, this time in the electronics responsible for identifying stars in the images taken. This led to Gaia reporting thousands of false detections of new objects of this type.
Gaia typically sends more than 25 gigabytes of data to Earth per day. However, if the probe’s onboard software did not eliminate false positivesthere would be much more of this data. Both incidents led to the probe’s systems being overloaded and for some time it was completely useless to scientists.
ESA suspects that the electronics failure could have been caused by a solar storm – we saw its effects in Poland in May. Even in Rzeszów, you could see auroras – with a bit of luck. The team responsible for Gaia was of course unable to repair it, but they managed to change the software a bit: they changed the threshold for classifying objects as stars, which allowed the probe to continue operating.
Gaia was launched in 2013 and was supposed to operate for about 6 years, but it has been successfully operating for more than a decade. It has helped astronomers detect the oldest stars in the Milky Way, which were born more than 12.5 billion years ago. It has also discovered faint companion stars to the main ones and binary systems, where the disk of one star eclipses the disk of the other. Thanks to data from the probe, scientists have even estimated when the Milky Way will merge with the Andromeda Galaxy – the collision will occur in about 4.5 billion years.
Gaia is scheduled to continue collecting data until the end of 2025, when its propulsion system runs out of fuel. It’s one of those probes that did a great job, even though it wasn’t initially appreciated. Just how long it was initially planned to last says a lot about how it was thought about. And here it is—it has exceeded the wildest expectations of the team responsible for its development, launch, and control.
Source: antyweb.pl
