NASA’s Europa Clipper mission to explore Jupiter’s ocean moons ready for launch

NASA’s Europa Clipper mission to explore Jupiter’s ocean moons ready for launch

Michael Greshko & Nature magazine

Scientists who have dreamed for decades of Jupiter’s moon Europa and the vast oceans that likely lie beneath its icy surface are now just weeks away from sending a spacecraft there. NASA confirmed yesterday that the Europa Clipper mission will launch as scheduled, despite concerns that a possible fault in a transistor on board the $5 billion spacecraft might force a major delay.

“I am confident that our incredible spacecraft and talented team are ready for launch and a full science mission to Europa,” Dr. Laurie Lessin, director of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, said at a September 9 press conference.

Massing more than 3.2 tonnes, standing almost 5 metres tall and over 30 metres wide with its solar panels fully deployed, Europa Clipper is the largest spacecraft ever built by NASA for a planetary exploration mission. Yesterday, the mission passed what’s known in NASA parlance as “Critical Decision Point E,” the final review hurdle that must be cleared before proceeding with launch. The spacecraft’s launch window begins on October 10th.

Support science journalism

If you enjoyed this article, please support our award-winning journalism. Subscribe. By purchasing a subscription, you help ensure a future of influential stories about the discoveries and ideas shaping the world today.

If its launch next month is successful, the probe will arrive at Jupiter in April 2030. Nine instruments will then study both Europa’s icy crust and the ocean that scientists suspect lies beneath it to determine whether the moon could support life as we know it. Previous missions have suggested that Europa’s icy surface conceals a saltwater ocean containing more than twice the volume of water as Earth’s oceans. The moon’s fissured, seemingly young surface also suggests the moon has active geology, suggesting that its interior may be warm and active enough for the complex chemical reactions of life.

There’s no device like the tricorder, a fictional instrument from the Star Trek universe, that can zero in on something and tell you if it’s life, said Kurt Niebuhr, Europa Clipper program scientist at NASA Headquarters in Washington, D.C., during a press conference. “Finding life is extremely difficult, especially from orbit,” he said. “First, we ask a simple question: Are the necessary ingredients for life to exist?”

Rough seas on the way to Sea World

Even before the transistor scare, Europa Clipper had experienced a number of setbacks. NASA detaches high-powered magnetometer from spacecraft, angering scientistsThe mission was canceled due to budgetary concerns. The mission also faced years of uncertainty about how to reach space, as the U.S. Congress had long mandated that the spacecraft fly on NASA’s long-delayed Space Launch System rocket. Finally, in 2020, Congress allowed the program to choose the reliable Falcon Heavy rocket from the private company SpaceX of Brownsville, Texas, for launch.

Possible transistor problem It reared its head in May this year When NASA engineers learned that some of the transistors already on board the Europa Clipper spacecraft were malfunctioning, the components, called MOSFETs (metal-oxide semiconductor field-effect transistors), which act like switches in electrical circuits, came from Infineon, a NASA supplier based in Neubiberg, Germany.

As Europa Clipper makes 49 passes by Europa, with the shortest distance covered being 15.5 miles (25 kilometers), the probe will also have to navigate through a barrage of charged particles accelerated by Jupiter’s magnetic field, which is about 20,000 times stronger than Earth’s, meaning the probe’s onboard electronics will have to withstand damaging radiation.

But in May, NASA said it was investigating whether the mission’s transistors might fail, and the space agency began four months of intensive, around-the-clock testing at three different facilities: JPL, the Johns Hopkins Applied Physics Laboratory in Laurel, Md., and NASA’s Goddard Space Flight Center in Greenbelt, Md. “This was a major accomplishment. I think ‘major accomplishment’ is an understatement,” Lesin said.

NASA evaluated spare MOSFETs from the same batch that was aboard the Europa Clipper and found that the spacecraft’s circuits performed as expected. This conclusion was based in part on the fact that during the first half of its four-year base mission around Jupiter, the spacecraft will only be exposed to the worst of Jupiter’s radiation for one day out of 21. The rest of the time, when gently heated, through a process called annealing, the orbiter’s transistors can partially self-repair from radiation damage.

“Europa Clipper will be immersed in a radiation environment, but once it’s out, it’ll be out long enough for the transistors to repair and partially recover during the flyby,” Jordan Evans, Europa Clipper project manager at JPL, said during the conference. “We’re confident, and the data supports that, that it will be able to complete its original mission.”

This article is reprinted with permission. First Edition September 10, 2024.