The European space telescope Gaia is embarking on its scientific mission, the 3D mapping of the Milky Way, despite some bad surprises. “Gaia is now ready to begin its five-year science phase, but its commissioning also revealed some unexpected anomalies”, announced the European Space Agency (ESA) in a statement.
Despite the setbacks, the ESA should be able to publish in 2016 the first “sky catalog”.
Launched by a Soyuz rocket from the French Guiana space center on December 19, Gaia is positioned on a privileged observation post, about 1.5 million kilometers from Earth.
It will be able to locate one billion stars in our galaxy, determining its position and movement, but also the distance that separates them from the Earth, the most difficult parameter to obtain. In 99% of cases, this distance was never precisely measured before.
“The implementation was difficult”, admitted Timo Prusti, scientific supervisor in charge of the project for ESA. But “as a whole, Gaia is well placed to fulfill its promise”, he added.
“All the basic goals are still achievable”, said Timo Prusti in the statement.
One of the problems found was ice formations on the lenses, surely from the water formed somewhere in the spacecraft before takeoff. The lenses were heated to remove the ice, but the operation must certainly be repeated during the mission.
Another problem was the level of “stray light” that Gaia found, which was higher than expected.
“We have optimized the on-board software to mitigate as possible the impact caused by the luminous background noise”, said Giuseppe Sarri, director of the ESA Gaia project.
“However, we will be able to analyze a billion stars or more, with an accuracy up to one hundred times than Gaia”s predecessor, Hipparcos”, he said.