# NASA’s Europa Clipper Mission: Set for Launch Despite Radiation Issues
Earlier this year, there was a brief moment when NASA’s eagerly awaited Europa Clipper mission encountered the risk of a significant postponement. In May, engineers expressed worries that specific transistors integrated into the spacecraft’s circuitry might be susceptible to the extreme radiation conditions surrounding Jupiter, potentially threatening the mission. Nevertheless, following months of thorough testing, NASA has approved the mission to move forward as scheduled, with a launch window beginning on October 10, 2024.
## Addressing Radiation Issues
The Europa Clipper mission aims to investigate Jupiter’s icy moon, Europa, which is thought to have a subsurface ocean beneath its frozen surface. This ocean might be capable of supporting life, rendering Europa one of the most captivating targets in the quest for extraterrestrial existence. Nonetheless, the spacecraft must navigate Jupiter’s intense radiation belts, which can harm delicate electronics.
The transistors in question handle approximately 200 distinct functions, many of which are vital for the spacecraft’s operations. These transistors are already in place on the spacecraft, and extracting or substituting them would have pushed the mission back to late 2025. Given the tight 21-day launch period starting October 10, 2024, NASA engineers had to devise a solution that would enable the mission to move forward without significant holdups.
Following comprehensive ground evaluations of similar transistors, engineers determined that the components on board Europa Clipper could endure the radiation conditions near Jupiter. “A major challenge was assessing how those transistors on the spacecraft would perform in Jupiter’s radiation environment,” remarked Jordan Evans, Europa Clipper’s project manager at NASA’s Jet Propulsion Laboratory (JPL). “After extensive testing and analysis, we have high confidence we can execute the original mission to explore Europa as intended.”
NASA’s senior management concurred with this evaluation, and the mission successfully cleared its final review, allowing launch preparations to proceed.
## Launch Preparations Underway
With the radiation issues addressed, teams at NASA’s Kennedy Space Center in Florida are now gearing up the spacecraft for launch. One of the next crucial phases involves loading nearly 3 metric tons (6,600 pounds) of propellant into the spacecraft. This propellant will make up almost half of the spacecraft’s total weight, making Europa Clipper the largest planetary exploration vehicle NASA has ever created.
Once filled with fuel, the spacecraft will be encased in its protective fairing and positioned atop a SpaceX Falcon Heavy rocket for its voyage to Jupiter. “I’m excited to announce that we are confident our remarkable spacecraft and skilled team are poised for launch, operations, and our comprehensive science mission at Europa,” stated Laurie Leshin, JPL’s center director.
## The Remarkable Mission Journey
Post-launch, Europa Clipper will set off on a multi-year expedition to the outer solar system. Initially, the spacecraft will execute a gravity-assist flyby of Mars in February 2025 to increase its speed. A second flyby of Earth in December 2026 will further refine its course, paving the way to intercept Jupiter’s orbit in April 2030.
Upon reaching Jupiter, Europa Clipper will fire its engines to decelerate and be captured by the gas giant’s tremendous gravitational pull. Over the span of four years, the spacecraft will conduct 49 close flybys of Europa, approaching as near as 16 miles (25 kilometers) from the moon’s icy surface.
During these flybys, Europa Clipper’s nine scientific instruments will map the moon’s surface, investigate its ice layer, and search for potential signs of habitability within the subsurface ocean. One of the mission’s most thrilling prospects is the chance to fly through plumes of water vapor that may be venting from fissures in Europa’s surface. If the spacecraft encounters such plumes, its instruments could directly analyze materials from the ocean beneath, providing an exciting glimpse into the moon’s potential for life.
“This is a groundbreaking mission,” commented Curt Niebur, Europa Clipper’s program scientist at NASA Headquarters. “It allows us to explore not a world that might have been habitable billions of years ago, but a world that could be habitable today, right now.”
## Radiation Defense and Self-Repairing Electronics
As Europa Clipper orbits Jupiter, it will encounter extreme radiation levels, but the spacecraft is equipped with strong protective solutions. The most sensitive electronic components are located within a vault made of aluminum-zinc alloy, which provides shielding from the most harmful radiation from Jupiter. However, some transistors are positioned outside this vault, particularly in the scientific instruments mounted on the spacecraft’s exterior.
Fortunately, the transistors possess a self-repair capability known as annealing, which enables them to regain much of their functionality after radiation exposure. For the majority of its orbit around Jupiter, Europa Clipper will traverse a relatively mild radiation environment, allowing time for the transistors to recover between close flybys.
