NASA’s Europa Clipper, depicted in this illustration that was updated in December 2020, will orbit Jupiter in an elliptical path, dipping close to its moon Europa on each flyby to collect data. Credit: NASA/JPL-Caltech
NASAS ‘ europe The Clipper mission is focused on solving transistor radiation issues as it prepares to launch on an expedition to Jupiter to explore the habitability of Europa.
The mission faces challenges with radiation-resistant transistors, found to be less resistant to Jupiter’s intense radiation. Tests at various NASA centers aim to address these issues.
Preparations for the launch of NASA’s Europa Clipper mission are progressing. The spacecraft was delivered to the Kennedy Space Center in Florida last May, and the team has successfully installed the high-gain antenna.
Engineers with NASA’s Europa Clipper mission continue to conduct extensive testing of the transistors that help control the flow of electricity on the spacecraft. The special versions used by the Europa Clipper are radiation hardened and intended to tolerate 100 to 300 kilorads, or krads (a “rad” is a unit of measurement for the absorbed dose of ionizing radiation).
However, the mission team at NASA’s Jet Propulsion Laboratory (JPL) in Southern California, which manages the mission, is evaluating test data showing that some transistors can be affected by significantly lower levels of radiation under some conditions. They are concerned that some of these parts may not withstand the radiation of the Jupiter system, which is the most radiation-intense environment in the solar system.
Radiation challenges and ongoing analysis
Tests are also being conducted at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, and at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. APL designed the spacecraft’s main body in collaboration with JPL and NASA Goddard.
The issue with the transistors came to light in May when the mission team was advised that similar parts were failing at lower radiation doses than expected. In June 2024, an industry alert was sent to notify users of this issue. The manufacturer is working with the mission team to support ongoing testing and radiation analysis efforts to better understand the risk of using these parts on the Europa Clipper spacecraft.
Durability and electronics solutions
Test data obtained so far indicate that some transistors are likely to fail in the high-radiation environment near Jupiter and its moon Europa, because the parts are not as resistant to radiation as expected. The team is working to determine how sensitive the transistors can be and how they will perform in flight. NASA is evaluating options for maximizing the lifetime of transistors in the Jupiter system. A preliminary analysis is expected to be completed by the end of July.
Radiation-hardened electronics are used throughout industry to protect spacecraft from radiation damage that can occur in space. Jupiter’s system is particularly harmful to spacecraft as its large magnetic field – 20,000 times stronger than Earth’s – traps charged particles and accelerates them to very high energies, creating the intense radiation that bombards Europa and other inner moons. It appears that the issue that may be affecting the transistors on the Europa Clipper is a phenomenon that the industry was unaware of and represents a newly identified gap in the industry standard radiation qualification of transistor wafer sets.
Mission objectives and future prospects
The Europa Clipper launch period opens on October 10 and will arrive at Jupiter in 2030, where it will conduct scientific investigations to understand the possible habitability of Europa as it flies past the moon many times.
The total cost of the Europa Clipper mission is estimated to be around $5 billion, making it one of the most expensive planetary science missions. This budget covers the development, launch and operation of the spacecraft for the duration of the planned mission.