The European Jupiter Icy Moons Explorer (JUICE) spacecraft will launch on an ambitious exploratory tour of Jupiter’s moons next week. But the mission will only take a brief glimpse of the potentially life-giving moon Europa. Here’s why.
surviving on as little power as half a hair dryer and featuring a “nuclear bunker” to protect its electronics from radiation, Jupiter’s Icy Moons Explorer (JUICE) It is a technological marvel that will not stand up to it Europa For a long time. smaller JupiterThe four major moons may be the most likely location in the world Solar System to host extraterrestrial life in its ice-covered ocean; However, the environment around the moon is so harsh, that it would kill a spacecraft in a couple of months at best, according to NASA.
Going to Jupiter is never easy. The closer I get gas giant And the longer you stay in the vicinity, the more difficult it will be. Five times away from sun From Earth, Jupiter lives in the solar system’s twilight zone, receiving only about 4% of the sunlight that our planet gets. This means that any visiting spacecraft that wish to rely on solar energy must have massive solar arrays. The challenges only begin here. Jupiter’s magnetic field is 10,000 times stronger than Jupiter’s Land, which could have an impact on the spacecraft’s scientific measurements, Justin Byrne, head of science programs at Airbus Defense and Space, which led the consortium building the JUICE spacecraft, told Space.com. Worst of all, this super-strong magnetic field traps particles being charged by Jupiter and its nearby, hypervolcanically active moon. Ayo Pumping space around the planet. As a result, radiation levels in close proximity to the planet are as high as the epicenter of a nuclear explosion.
Related: Ha! Closest view of Jupiter’s moon in the ocean Europa in 22 years
Satellite radiation sickness
Europa orbits Jupiter at a distance of 417,000 miles (671,000 km), nearly twice the distance between the Moon and Earth, and is the second closest moon to Jupiter. Radiation levels around Europa are not quite as high as they are around the nearest Io, however, scientists know that the radiation dose an object in orbit around Europa would receive in a single day, at 5.4 Sv, is more than twice the value that would cause severe radiation sickness to humans. Of course, the starship isn’t human, but Byrne admits that those radiation levels are beyond what spacecraft designers are used to building for.
“We’re so used to radiation in space,” Byrne said. “Earth orbiting missions have to pass through Earth radiation beltsBut the radiation levels there are nowhere near what a spacecraft would experience near Jupiter.”
High levels of radiation are bad news for electronics and solar panels. The higher the radiation intensity, Byrne said, the faster electronic systems fail, and the faster solar arrays degrade. For this reason, NASA-specific Europa Clipper The mission will not search for traces of life on Europa directly from lunar orbit, but will instead make short periodic visits while in a wider orbit around Jupiter. It is for this reason that the European Space Agency (ESA) chose Jupiter’s largest moon and somewhat more comfortable Ganymedeas a primary goal of JUICE.
Although Ganymede is less likely to harbor life than Europa, according to scientists, the moon is far from boring. Larger than the smallest planet in the solar system MercuryGanymede is the largest moon in the entire solar system and the only one known to generate its own magnetic field. In 2034, three years after the JUICE arrived at Jupiter (if all goes as planned), Ganymede will become the first moon far from Earth’s moon. moon a spacecraft in orbit.
Ganymede orbits Jupiter at a distance of 665,000 miles (1,070,000 km), and is the third closest to the gas giant of the four major moons. Byrne said that the radiation around Ganymede is about 100 times weaker than that of Europe. However, the JUICE spacecraft would not be able to survive in this environment for long without some of the solutions used before.
At the heart of the spacecraft is a 2.7-tonne (2.42 metric tons) lead-lined vault that houses all of the spacecraft’s electronics (except for science instruments designed to study the extreme environment in the Jupiter system).
“There are kilograms of lead in the juice,” Byrne said. “This effectively limits the amount of radiation that can reach electronic devices and extends their life. But eventually, they will die. You can’t stop that forever.”
If the spacecraft were to go to Europe, Byrne added, this small lead-lined nuclear bunker would have to be more powerful.
The death of solar panels
But while there is a solution to protecting electronic systems, solar arrays are quite vulnerable to radiation. Byrne believes degradation of the juice’s solar panels in the harsh environment around Jupiter will lead to the mission’s eventual demise.
Given Jupiter’s distance from the Sun and the low intensity of sunlight around the planet, JUICE’s solar panels must have been enormous. Designed as two cruciform wings, the two arrays cover an area of 915 square feet (85 square meters). Despite this massive size and record efficiency of about 30%, the arrays don’t even produce enough electricity to power a hair dryer, Byrne said.
“It’s really a very small amount of energy, and as it deteriorates over its lifetime due to radiation, its performance will degrade to the point where there won’t be enough energy to run the task,” Byrne said.
JUICE was designed to survive a combined four years orbiting first Jupiter and then Ganymede. Before entering Ganymede’s orbit, the spacecraft will make two flybys of Europa, 21 on the farthest and least explored moon Callistoand 12 in Ganymede. Byrne is confident that Airbus engineers and collaborators from across Europe have built a spacecraft powerful enough to accomplish its mission. However, JUICE is not likely to exceed life expectancy, unlike many other missions.
“It may last a little longer but it won’t last 10 years like many other missions do,” Byrne said.
In addition to the intense radiation environment, the mission will also consume a huge amount of fuel due to the large amount of fuel-guzzling flights from Jupiter’s moons.
“There will be a lot of course corrections, course changes,” Byrne said. “It’s going to require a lot of fuel. So either you’ll run out of fuel first, or the solar arrays will decompose, and that will finish the job.”
The operators will want to finish the JUICE mission in time by sending it to crash at Ganymede in order to prevent the spacecraft from turning into an out of control piece. space junk And it is likely to crash into Europa later, contaminating it with terrestrial microbes. Since scientists don’t think Ganymede is likely to host life, and since its surface doesn’t appear to be in contact with the subsurface ocean (unlike that of the more active Europa), experts aren’t worried about JUICE jamming the moon’s pure ice crust. .
So what would it take to send the juice into orbit around Europe?
But with all these challenges, does that mean it’s impossible for a spacecraft to orbit Europa, the most likely place in the solar system to host extraterrestrial life?
Byrne says engineers are currently studying these possibilities in hopes of sending a sterilized lander to Europe in the distant future.
“It’s a challenge to be seen,” Bayern said. “You would need more protection for the electronics and probably much larger solar arrays. That would mean a lot more mass. But we can probably do that.”
Such a task, according to JUICE launch kit from ESA (Opens in a new tab), did not take off until years after NASA’s JUICE and Clipper (scheduled to launch next year) completed their missions. The two tasks, which will succeed Juno from NASA The spacecraft, which has been studying Jupiter since 2016, is setting the stage for our final encounter with potential microbial life on Europa.
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