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Banner image: Jupiter's icy moon Europa as seen by NASA's Galileo spacecraft in the late 1990s. (Credit: NASA/JPL-Caltech/SETI Institute)

In less than a decade, technology developed in Colorado will travel to Jupiter’s moon Europa—a cold moon where a thick crust of ice covering the surface obscures a potentially vast ocean of saltwater below.   

That piece of Rocky Mountain technology is the Europa (SUDA). The more than $50 million instrument was designed and built by a team of scientists and engineers at the ��������’s (LASP). It’s part of NASA’s larger mission, which will investigate the icy moon to determine if it has conditions that could support life. 

LASP shipped SUDA this month to NASA’s Jet Propulsion Laboratory in southern California, which leads the mission. SUDA and eight other scientific instruments are set to launch in October 2024 aboard the Europa Clipper spacecraft, beginning a nearly five-and-a-half-year journey to Jupiter. There, it will conduct multiple flybys of Europa. 

“SUDA is a remarkable instrument designed and constructed by remarkable people,” said LASP Director Dan Baker. “It builds on our lab’s rich heritage of dust instrumentation while incorporating new technologies and techniques developed just for this mission. We can hardly wait to see SUDA’s first results.”

SUDA will be a key player in Europa Clipper’s quest, added Sascha Kempf, the instrument’s principal investigator. 

The instrument’s sensor head, which is coated with an extremely thin layer of 99.99% gold, is about the size of a marching drum and weighs nearly 35 pounds. As Europa Clipper flies by the moon, SUDA will collect and analyze particles ejected from the moon’s surface by tiny meteorites. JPL scientist and SUDA co-investigator Murthy Gudipati compared the instrument to a shark swimming with its mouth open. Scientists can also use data from the instrument to track where on the surface those particles launched from.

“We will collect material from the surface, and we will do that without ever landing on the surface,” said Kempf, an associate professor at LASP and the Department of Physics at CU Boulder. 

It’s also a monumental achievement for the dozens of researchers at LASP who have toiled since 2015, through a historic pandemic, to make the instrument a reality. Planetary Pigpen

Scientists have long had their eyes on Europa as an important target in the search for life beyond Earth. 

This ice-covered sphere is slightly smaller than Earth’s own moon, and only the fourth largest of Jupiter’s moons behind Ganymede, Callisto and Io. Underneath its miles-thick layer of ice, however, researchers suspect that Europa could hold more than twice the saltwater of all of Earth’s oceans combined—an ocean that might also carry ingredients necessary to sustain living organisms, including organic molecules like amino acids.

Europa Clipper is not a life-finding mission. But it will conduct a detailed investigation of the moon and, among other goals, determine if those key ingredients for life are present. 

Scott Tucker, the SUDA project manager at LASP, explained that micrometeorites are constantly pinging the surface of Europa. In the process, they kick up tiny particles from the moon’s surface, sometimes ejecting bits of moon stuff several miles into space. Researchers estimate that roughly half a ton of material surrounds Europa at all times. 

“There’s, essentially, a thin sphere of particles around the moon,” Tucker said. “It’s like Pigpen in the Peanuts comics with his cloud of dust.”

A panel located on the side of the senor head for Europa Clipper’s dust analyzer. (Credit: NASA/LASP/CU Boulder)

Engineer inspects a space instrument in a clean room at LASP. (Credit: Glenn Asakawa/CU Boulder)

SUDA will use its wide mouth to capture those particles. These tiny grains will be moving at relative speeds of more than 10,000 miles per hour—so fast that when they hit the target that sits at the back of the instrument, they will vaporize on impact. SUDA collects the ions that escape from those collisions and measures them to determine exactly what the particles were made of.

The instrument is so sensitive that it can detect amino acids mixed in with ice at concentrations of about 1 part per million. Scientists can also use data from SUDA to pinpoint where on the moon those particles originated to within about 10 miles. 

Keeping it clean

Getting SUDA to Europa, or even California, however, hasn’t been easy. 

Over seven years, roughly 150 scientists and engineers at LASP have worked on the instrument, including about 40 undergraduate and graduate students.

To make sure that SUDA’s target could withstand all of those impacts from dust, the group partnered with researchers at JILA on the CU Boulder campus to coat this disk in a thin layer of iridium—one of the hardest and densest naturally-occurring metals on Earth.

Kempf added that SUDA is also a marvel of cleanliness. The team, he said, needs to be sure that SUDA will transport almost no contaminants from Earth to Europa. To achieve that feat, engineers from LASP heated the instrument to 239 degrees Fahrenheit for about 17 hours to kill off living organisms like bacteria. They also ran sterile nitrogen gas through SUDA while working with it to flush out unwanted contaminants from the air. 

“We have to be able to demonstrate that the material we detect is from Europa and not from us,” Kempf said. “That’s why we drove our engineering team so hard with our handling procedures.”

The stress, however, will pay off once SUDA and Europa Clipper make it to the icy moon in 2031. When they do, the instrument will bring a symbol of Colorado with it—an image of Ralphie, CU Boulder’s buffalo mascot, which the SUDA team etched onto one of the instrument’s gold-plated panels using a laser. 

“The chance to be a part of the discovery of an environment capable of supporting life beyond Earth is what has kept us going through COVID and everything else,” Tucker said. “There’s no immediate gratification with this mission, but it’s worth it knowing that we’re going to be part of something really amazing.”

Managed by Caltech in Pasadena, California, JPL leads the development of the in partnership with the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, for NASA’s Science Mission Directorate in Washington. The Planetary Missions Program Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, executes program management of the Europa Clipper mission.