NASA’s Europa Clipper mission passed a mission planning milestone, known as Key Decision Point E, on Monday. It now is approved to continue to proceed toward launch, with a launch period that opens Thursday, Oct. 10.
Author: Erin Morton
NASA Continues Assessing Electrical Switches on Europa Clipper
Launch preparations are progressing with NASA’s Europa Clipper mission. The spacecraft arrived at the agency’s Kennedy Space Center in Florida in May, where the team recently attached the high-gain antenna.
Engineers with NASA’s Europa Clipper mission continue to conduct extensive testing of transistors that help control the flow of electricity on the spacecraft. NASA’s Jet Propulsion Laboratory in Southern California, which manages the mission, began the tests after learning that some of these parts may not withstand the radiation of the Jupiter system, which is the most intense radiation environment in the solar system.
Tests also are being conducted at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland. APL designed the main spacecraft 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 out to notify users of this issue. The manufacturer is working with the mission team to support ongoing radiation test and analysis efforts in order to better understand the risk of using these parts on the Europa Clipper spacecraft.
Testing data obtained so far indicates some transistors are likely to fail in the high-radiation environment near Jupiter and its moon Europa because the parts are not as radiation resistant as expected. The team is working to determine how many transistors may be susceptible and how they will perform in-flight. NASA is evaluating options for maximizing the transistors’ longevity in the Jupiter system. A preliminary analysis is expected to be complete in late July.
Radiation-hardened electronics are used throughout industry to protect spacecraft from radiation damage that can occur in space. The Jupiter system is particularly harmful to spacecraft as its enormous magnetic field — 20,000 times stronger than Earth’s magnetic field — traps charged particles and accelerates them to very high energies, creating intense radiation that bombards Europa and other inner moons. It appears that the issue that may be impacting the transistors on Europa Clipper is a phenomenon that the industry wasn’t aware of and represents a newly identified gap in the industry standard radiation qualification of transistor wafer lots.
Europa Clipper’s launch period opens Oct. 10, and it is set to arrive at Jupiter in 2030, where it will conduct science investigations to understand the potential habitability of Europa as it flies by the moon multiple times.
NASA Examines Electrical Switches on Europa Clipper Spacecraft
As NASA’s Europa Clipper continues preparations in advance of its launch period — opening Oct. 10 — the mission team is assessing whether transistors on the spacecraft can withstand the intense radiation the probe will encounter at Jupiter.
These transistors are used as electrical switches in many digital electronics. The particular versions used by Europa Clipper are radiation-hardened and are intended to tolerate 100 to 300 kilorad, or krad (a “rad” is a unit of measure for absorbed dose of ionizing radiation). However, the mission team at NASA’s Jet Propulsion Laboratory in Southern California, which manages the mission, is assessing test data that indicates some transistors could be affected by significantly lower radiation levels in some conditions.
The team is conducting more extensive testing to better characterize the transistor behavior and whether it may affect the functionality of the circuits on Europa Clipper. The agency has time to continue this work as the spacecraft proceeds toward its October launch period.