Jupiter’s moon Europa is one of the most promising places to search for extraterrestrial life.
Europa is not just one of Jupiter’s many moons; It is also one of the most promising locations of the solar system to search for extraterrestrial life. There is a liquid country Oceans under 10 kilometers of ice could support life. However, it is one of the harshest places in solar system, with a surface temperature of -180 degrees Celsius and extreme radiation levels. The discovery of Europa could be made possible in the coming years as a result of Georgia Tech’s research on silicon-germanium transistor technology.
Professor John D. Cressler of the Electric School and Computer The engineer (ECE) and his students have been working with silicon-germanium heterojunction bipolar transistors (SiGe HBT) for decades and have discovered that they have unique advantages in the environment. as harsh as Europa.
“Because of the way they’re made, these devices actually survive those extreme conditions without any changes to the underlying technology itself,” says Cressler. Who project investigator. “You can build it for what you want it to do The earthand then you can use it in space. “
Scientists are in the first of three years of NASA’s Ocean World Concepts Life Funding Detection Technology (COLDTech) to design the avionics infrastructure for future Europa surface missions. NASA plans to launch Europa Clipper, an orbiting spacecraft that will map Europa’s oceans, in 2024, then send a landing vehicle, Europa Lander, to drill through the ice and explore the ocean. its. But it all starts with electronics that can operate in Europa’s harsh environment.
In a paper presented at IEEE Nuclear and Space Radiation Effects Conference in July, Cressler and his students, along with researchers from NASA The Jet Propulsion Laboratory (JPL) and the University of Tennessee (UT), demonstrated the capabilities of SiGe HBTs against this hostile environment.
Europa’s Challenge
Jupiter, like Earth, has a liquid metal core that generates a magnetic field, resulting in radiation belts of high-energy protons and electrons from the solar wind. Unfortunately, Europa, as a Jupiter The moon, which lies directly in the path of those radiation belts. In fact, any technology designed for Europa’s surface would need to be able to withstand not only the cold temperatures but also the worst radiation of the solar system.
The SiGe HBT is, fortunately, ideal for this harsh environment. SiGe HBT embeds a nano-sized Si-Ge alloy inside a standard bipolar transistor to nanoengineer its properties, resulting in a much faster transistor while preserving economies of scale. and low cost of traditional silicon transistors. SiGe HBTs have the unique ability to maintain performance even when subjected to high radiation levels and their properties are naturally improved at lower temperatures. Because of this one-of-a-kind combination, they are ideal candidates for the Europa expedition.
“It doesn’t just do basic science and prove that SiGe works,” says Cressler. “It’s really growing electronic device for NASA use on Europa. We know SiGe can exist at high levels of radioactivity. And we know it still works in cold temperatures. What we don’t know is whether it can do both of these things at once, which is necessary for Europa. face mission. “
Check Transistor
The GT researchers used JPL’s Dynamitron, a machine that shoots high-flux electrons at extremely low temperatures, to test SiGe in a Europa-like environment. At 300, 200 and 115 Kelvins, they expose SiGe HBTs to one electron million Volt and radiation dose of 5 million rads (200-400 rads lethal) (-160 degrees Celsius).
“What has never been done is to use electronics like we did in that experiment,” Cressler said. “So we literally worked for the first year to get the results in that paper, in essence, hard evidence that what we were claiming was, in fact, is true – that SiGe survives Europa’s surface conditions.”
The GT and UT researchers will spend the next two years developing practical SiGe circuits that can be used on Europa, such as radios and microcontrollers. More importantly, these devices could then be used in almost any space environment, including on Mars and the moon.
“If Europa is the worst environment in the solar system, and you can build these to work on Europa, then they will work anywhere,” Cressler said. “This research ties in with previous research that we’ve been doing in my team here at Georgia Tech for a long time and shows really interesting and novel applications of these technologies. We pride ourselves on using our research to break new ground of innovation and thus enable new applications.”
