NASA’s Europa Clipper Mission at Risk Of Major Delay Following Radiation Vulnerability Discovery

NASA’s Europa Clipper mission, a $5 billion flagship endeavor to explore Jupiter’s ocean moon, is facing significant challenges due to concerns over the durability of transistors aboard the spacecraft. Scheduled to launch in October, the mission aims to assess Europa's habitability, but the harsh radiation environment around Jupiter could jeopardize the spacecraft's functionality.

NASA has confirmed that the Europa Clipper's transistors might not withstand the intense radiation of the Jovian system, raising doubts about the mission’s scientific objectives. The spacecraft's inability to endure Jupiter's radiation could lead to a lengthy delay, potentially hindering the mission’s goal of determining if Europa could support life.

Engineers worry about two types of radiation dosages: the total ionizing dose, which accumulates over time, and the flux dose, or radiation surges. Radiation can corrupt data, cause short circuits, disrupt voltage levels, and damage electronics. To combat this, spacecraft are equipped with shielding, radiation vaults, or radiation-hardened components. However, recent tests revealed that critical radiation-resistant chips on the Europa Clipper failed at lower-than-expected radiation levels.

“Characterizing the spacecraft’s newfound vulnerability to radiation is an ongoing activity,” - Jordan Evans, Europa Clipper Project Manager at NASA’s Jet Propulsion Laboratory (JPL),

The defective chips, known as metal-oxide-semiconductor field-effect transistors (MOSFETs), are crucial to the mission’s success. Manufactured by Infineon Technologies, the chips in question are also used in military spacecraft.

“We’re seeing some of these MOSFETs fail at lower radiation levels than the prevailing environment around Europa,” - Shannon Fitzpatrick, Head of Flight Programs for NASA’s Planetary Science Division

Engineers at JPL and Johns Hopkins University Applied Physics Laboratory spent over 20 years designing a spacecraft and flight path to withstand Jupiter's radiation. To minimize exposure, the Europa Clipper will orbit Jupiter and make periodic close passes to Europa, rather than orbiting the moon directly. This strategy, coupled with a suite of specialized scientific instruments, aims to capture 90 percent of Europa’s surface in high detail over a four-year mission.

Europa, roughly the size of Earth’s moon, has an ice shell covering an ocean with twice the amount of liquid water as all of Earth’s oceans combined. This ocean, interacting with its seafloor and organic materials from comets and asteroids, could potentially harbor life. However, confirming this requires the Europa Clipper to endure Jupiter's severe radiation environment.

This month, a "tiger team" at JPL will share preliminary results of their chip studies with the mission’s scientists and engineers. Collaborating with experts from NASA’s Goddard Space Flight Center and Johns Hopkins University Applied Physics Laboratory, the team aims to determine how long the spacecraft could survive around Europa if launched as planned.

“The tiger team is carrying out an extensive test program.” - Shannon Fitzpatrick, Head of Flight Programs for NASA’s Planetary Science Division

NASA must decide whether to proceed with the current plan or delay the launch for further mitigation. A potential delay would involve disassembling the spacecraft to replace the faulty chips, a process that could take several months to a year. If the chips are scarce, engineers might need to find substitutes from other vendors, requiring a complete re-evaluation of the spacecraft, potentially delaying the mission by years.

Despite these challenges, NASA remains focused on ensuring the Europa Clipper is capable of answering key questions about Europa’s habitability. The spacecraft arrived at Kennedy Space Center in Florida in May, where launch preparations are progressing, including the attachment of the high-gain antenna.

Extensive testing continues at JPL, Johns Hopkins Applied Physics Laboratory, and NASA’s Goddard Space Flight Center. In June, an industry alert notified users of the transistor issue, with ongoing support from the manufacturer to understand the risk. Preliminary analyses indicate some transistors may fail in Jupiter’s high-radiation environment, leading NASA to evaluate options for maximizing their longevity. A preliminary analysis is expected in late July.

Radiation-hardened electronics protect spacecraft from space radiation, particularly in Jupiter’s harmful radiation environment. The issue impacting Europa Clipper’s transistors represents a newly identified gap in industry standards.

The launch window for Europa Clipper opens on October 10, with an expected arrival at Jupiter in 2030.