Credit – NASA JPL-Caltech
NASA has raised concerns about the durability of transistors on the $5 billion Europa Clipper spacecraft, designed to explore Jupiter’s moon, Europa. The spacecraft’s ability to function amid Jupiter’s intense radiation environment is under scrutiny, potentially threatening the mission’s timeline and objectives. Scheduled for an October launch, Europa Clipper aims to assess the potential habitability of Europa, a moon with a subsurface ocean. Experts caution that without addressing the equipment issue, the mission might fall short of its scientific goals.
The primary concern revolves around the transistors’ ability to withstand the powerful radiation in Jupiter’s vicinity. Transistors, fundamental components of computer chips and electronics, may fail under the extreme radiation of the Jovian system. Radiation from cosmic rays and solar eruptions permeates space, but Europa orbits within the particularly hazardous Jovian radiation belt, where radiation levels can be over 50 times higher than around Earth.
Radiation Challenges and Mitigation Efforts
Scott Bolton, principal investigator of NASA’s Juno spacecraft currently orbiting Jupiter, explained the dual radiation threats: the total ionizing dose, accumulating over time, and flux dose, or radiation surges. These threats can corrupt data, cause short circuits, disrupt voltage levels, and damage electronics. To mitigate these risks, engineers typically use shielding, build radiation vaults, or employ radiation-hardened components. However, a recent test revealed that radiation-resistant chips, critical to the mission, failed at lower radiation levels than expected.
On May 3, NASA’s Jet Propulsion Laboratory (JPL) learned from an external source that the essential chips failed under lower radiation conditions than required. Jordan Evans, the Europa Clipper project manager, reported this issue to the Space Studies Board, emphasizing the ongoing efforts to address the problem. The compromised chips, known as metal-oxide-semiconductor field-effect transistors (MOSFETs), are manufactured by Infineon Technologies, a German semiconductor company. While Infineon declined to comment on specific customers, they assured compliance with quality and performance standards.
Path Forward and Mission Significance
To minimize radiation exposure, the Europa Clipper will orbit Jupiter and make periodic close passes to Europa, approaching within 15 miles at various angles. Over its four-year mission, it aims to capture 90 percent of Europa’s surface in high detail. The spacecraft’s scientific instruments are designed to investigate Europa’s potential to support life. Europa, similar in size to Earth’s moon, has a subsurface ocean containing twice the liquid saltwater found on Earth. This ocean has been in chemical interaction with its rocky seafloor and organic material from comets and asteroids for four billion years. Understanding how radiation affects Europa’s ocean is crucial for assessing its habitability.
This month, a dedicated team at JPL, referred to as the “tiger team,” will share preliminary findings on the chip issue with mission scientists and engineers. Collaborating with experts at NASA’s Goddard Space Flight Center and the Johns Hopkins University Applied Physics Laboratory, the team is rigorously testing the spacecraft’s components. Shannon Fitzpatrick, head of flight programs for NASA’s Planetary Science Division, highlighted the ongoing efforts to manage the risk, indicating that there is still time to address the issue.
The tiger team and lab management will ultimately provide a formal recommendation on how to proceed with the spacecraft. The outcome of this assessment will be critical in determining whether the Europa Clipper can launch as planned and achieve its mission to explore one of the most intriguing moons in our solar system.
Also read: NASA Conducts Planetary Defense Exercise To Prepare For Asteroid Threats
