This is so that you can generate enough electricity to operate the scientific instruments, the electricity consumption of all together is less than that required to operate a microwave

NASA's Europa Clipper spacecraft was recently fitted with two giant solar arrays at the Kennedy Space Center in Florida. The arrays, each about 14.2 meters long and 4.1 meters high, are the largest NASA has ever developed for a planetary mission. They must be large so they can absorb as much sunlight as possible when the spacecraft explores Jupiter's moon Europa, which is five times farther from the Sun than Earth.
The arrays were folded and locked into the central body of the spacecraft for launch, but when opened in Europa Clipper space the width will be more than thirty meters - several meters longer than a standard basketball court. The "wings", in the language of the engineers, are so large that only one of them can be opened at a time in the clean room at the NASA facility where the spacecraft is being prepared for its launch window, which will open on October 10.

Meanwhile, engineers continue to evaluate tests of the radiation tolerance of transistors in the spacecraft. Longevity is important, because the spacecraft will fly for more than five years until it reaches the Jupiter system in 2030. As it attacks the gas giant, the probe will make several close flybys of Europa, and will use a suite of scientific instruments to find out whether the ocean beneath the ice sheet has conditions that could support life.
To provide electricity to these beauties in a region of the solar system that receives only 3-4% of the sunlight that the Earth receives, each solar array consists of five panels. They are much more sensitive than the solar arrays that are placed on residential houses, and the very efficient spacecraft will make the most of the electricity they produce.
Watch engineers and technicians disassemble and test the large Europa Clipper solar arrays in a clean room at the Kennedy Space Center in Florida. Credit: NASA/JPL-Caltech/KSC/APL/Airbus
Rightly so, the Europa Clipper arrays will together provide electricity with a power of about 700 watts, about the amount necessary to operate a small microwave or coffee machine. In the spaceship, batteries will store the electricity to operate all the electronics - scientific instruments, communication equipment, the computer and a complete propulsion system that includes 24 engines.
The arrays must operate in extreme cold when doing all this. The temperature of the equipment will drop to minus 240 Celsius when it is in Jupiter's shadow. To ensure the panels could operate in these extreme conditions, engineers tested them in a special cryogenic chamber at the Space Center in Belgium.

"The spacecraft is warm. It has heaters and an active thermal loop, which keep it in the range of much more normal temperatures," said Tajo Lee, product supply manager for the solar arrays. "But the solar arrays are exposed to the vacuum of space without heaters. They are completely passive, so they always receive the ambient temperature."
About ninety minutes after the launch, the arrays will unfold from the folded position for about forty minutes. About two weeks later, six antennas connected to the arrays will also open to their full size. The antennas belong to the radar device, which will look for water in and under the moon's thick ice cover. They are huge, opening to a length of 17.6 meters perpendicular to the arrays.
"At the beginning of the project, we thought it would be almost impossible to develop a solar array that would be strong enough to hold these huge antennas," Lee said. "It was difficult, but the people who came to the challenge are a lot of creativity, and we solved it."
Europa Clipper's three primary science goals are to determine the thickness of the moon's ice mantle and its interactions with the ocean beneath it, study its composition, and characterize its geology. The mission's detailed exploration of Europa will help scientists better understand the astrobiological potential of habitable worlds beyond our own.
More of the topic in Hayadan: (Beresheet is the Hebrew name for the book of Genesis)