The cruise phase lasts until November 2021 and from there the scientific phase of the mission will begin.
MADRID, 29 Jun. (EUROPA PRESS) –
The Solar ship Orbiter of the European Space Agency (ESA) It has successfully completed four months of painstaking technical verification, known as commissioning. Despite the challenges posed by the COVID-19 pandemic, the spacecraft is now ready to start doing science as it continues its cruise to the Sun.
When Solar Obiter took off into space on an Atlas V rocket from Cape Canaveral, Florida on February 10, the teams behind the 1.5 billion euro mission did not anticipate that in a few weeks, the spread of COVID-19 would evict them from their control rooms, making the challenging start-up process for the spacecraft’s instruments even more difficult.
Under normal circumstances, many of the project scientists and engineers would have met at the European Center for Space Operations (ESOC) in Darmstadt, Germany. Together, they would have worked closely with spacecraft operators to bring the spacecraft and its instruments to life.
This happened more or less as usual during the first few weeks, the most challenging of Solar Orbiter’s orbiting existence, but when the instrument kits were invited to ESOC in March, the situation in Europe was changing rapidly.
Although they met a week later, it became clear that the European countries were on their way to closure, and therefore external teams were asked to return to their homes. The situation became even more serious when several ESOC workers tested positive for the coronavirus and the site closed its doors until further notice.
“We had to protect people“says Sylvain Lodiot, ESA’s Solar Orbiter Operations manager, whose last task before going home was to turn off all the instruments on the ship.”It was horrible because I didn’t know when those instruments would come back online“, dice.
However, a week later a team of few people returned, and with the current social distancing measures they began to work remotely with instrument kits to perform commissioning.
THE MOST AFFECTED, THE SWA
One of the most affected instrument teams was the Solar Wind Analyzer (SWA) team. The solar wind, which is constantly released from the Sun, is made up of a mixture of electrically charged particles called ions and electrons. The SWA instrument consists of three different sensors to measure the fluxes and composition of these various populations of particles. Each sensor works as a kind of ‘electric periscope’ that uses high voltages, up to 30 kilovolts, to divert particles from the solar wind towards the detector.
To safely operate those high voltages, the team had planned not to turn the instrument on until at least a month after launch. This was intended so that no traces of Earth’s atmosphere remained within the SWA sensors. If there were, these high voltages could cause damage to the sensors.
The ignition process for each of the SWA detectors is lengthy, as each high-voltage subsystem must ignite in steps of only 20 or 50 volts at a time. After each increase, the instrument is checked to ensure that nothing bad has happened.
READY FOR SCIENCE
The other instrument kits also successfully completed commissioning and, for the first time, from workers’ homes. And not only did the work get done, they made up for lost time and managed to complete their startup on the original timeline.
So now the mission is ready to do science. “In these four months since launch, the 10 instruments on board have been carefully reviewed and calibrated one by one, like tuning individual musical instruments. And now is the time for them to act together,” says Daniel Müller, project scientist at Solar. ESA’s Orbiter.
This month, June 17-22, was the first opportunity for all instruments to ‘play’ together. Reception of the recordings of the spacecraft, which is currently more than 160 million kilometers away, will be completed in the coming days.
“We are very excited about this first ‘concert’. For the first time, we will be able to gather images from all of our telescopes and see how they take complementary data from various parts of the Sun, including the surface; the outer atmosphere or corona; and the heliosphere more wide around him. This is what the mission was built for, “adds Müller. These first light images will be released to the public in mid-July.
100 DAYS OF DATA
Other instruments are also already collecting data. In the case of the magnetometer (MAG), it turned on just a day after launch. “We got data of less than 100 days during the commissioning period, and it’s wonderful data,” says Helen O’Brien of Imperial College and MAG’s chief engineer.
MAG was turned on early so that he could take readings as he was taken from the spacecraft as his feather arm was deployed.
Those data will allow the team to understand the spacecraft’s generated magnetic field, so they can now remove it from their scientific data to leave only the magnetic field that is carried into space away from the Sun. And there is already a lot of data – more than 2 billion of scientific measurements to analyze.
The mission is now continuing its course to the Sun. During this cruise phase, the spacecraft’s on-site instruments will collect scientific data on the environment around the spacecraft, while the remote sensing instruments will be adjusted by teams in preparation for scientific operations near the Sun. The cruise phase lasts until November 2021, and thereafter, Solar Orbiter will begin the scientific phase of its mission.
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