NASA’s Europa Clipper spacecraft today began its six-year cruise to the Jupiter system, with the goal of determining whether one of the giant planet’s moons has the right stuff in the right setting for life.
The van-sized probe was sent into space from NASA’s Kennedy Space Center atop a SpaceX Falcon Heavy rocket at 12:06 p.m. ET (16:06 UTC). A little more than an hour after launch, the spacecraft separated from its launch vehicle to begin a roundabout journey of 1.8 billion miles (2.9 billion kilometers) from Earth orbit to Europa.
For decades, scientists have been collecting evidence that Europa harbors a hidden ocean of salty water beneath its icy shell. Or are they hidden lakes? Europa Clipper is built to characterize the moon’s surface, and what’s beneath that surface, to an unprecedented degree.
The spacecraft won’t actually land on Europa. Instead, it will document the moon’s chemical composition, magnetic field, gravity field and subsurface structure over the course of four years, during 49 flybys that will pass as close as 16 miles (25 kilometers) above the surface.
“Europa Clipper carries the most sophisticated suite of instruments that we’ve ever sent to the outer solar system,” mission project scientist Bob Pappalardo said during today’s webcast.
“It carries a radar that can penetrate through ice like a CAT scan to find liquid water,” he said. “Super-high-resolution imaging will be able to look for warm spots, plumes at Europa — all these wonderful techniques that combine together to tell us, ‘Could Europa be the kind of place that could support life today?'”
Europa Clipper is the most massive interplanetary probe built for NASA, with a fueled-up weight of 13,000 pounds (6,000 kilograms). Putting the spacecraft on its proper trajectory required so much oomph that there wasn’t enough propellant left over for the recovery of SpaceX’s rocket afterward.
Getting the spacecraft off the pad was an odyssey in itself: This summer, mission planners worried that the probe’s radiation shielding wasn’t strong enough to protect its electronics, but those concerns were eased. Last week, Hurricane Milton forced a postponement of the Florida launch, but after the storm passed, NASA and SpaceX gave the all-clear for today’s attempt. During the countdown, the launch team detected — and successfully resolved — a last-minute temperature anomaly on the Falcon Heavy’s second stage.
On its way to the Jupiter system, Europa Clipper will rely on gravity boosts provided during a flyby of Mars next March, and during an Earth flyby at the end of 2026.
Once the spacecraft gets to its destination in 2030, it will fly over Europa repeatedly, following a flight path that’s meant to minimize exposure to the intense emissions from Jupiter’s radiation belts.
Europa Clipper’s science instruments include visible-light, ultraviolet and infrared cameras that will map the ridges and cracks in Europa’s surface — and check for thermal clues that could point to upwellings of liquid water.
Spectrometers will determine the chemical composition of the surface ice and “sniff” Europa’s thin atmosphere. Ice-penetrating radar and a gravity field detector will map Europa’s internal structure. Two instruments will chart the magnetic field, producing data that could confirm the depth and salinity of Europa’s subsurface ocean. A dust analyzer will sample the material that’s thrown up from the surface, to track down its composition and figure out where it’s coming from.
The spacecraft is also carrying a radiation-shielding plate that is decorated with graphical representations of the word “water” in 103 languages — in recognition of Europa’s status as a water world — plus a poem for Europa, celestial equations and other tributes. The names of 2.6 million people around the world have been etched in microscopic letters onto a silicon chip that’s attached to the plate, thanks to a “Message in a Bottle” campaign organized by NASA.
Is there life in Europa’s hidden ocean? Scientists say the $5.2 billion Europa Clipper mission shouldn’t be expected to answer that question definitively. “We’re not looking for life itself. We’re just looking for an environment in which life could thrive,” Kate Craft, a staff scientist at Johns Hopkins University’s Applied Physics Laboratory, said in a video about the mission from NASA’s Jet Propulsion Laboratory. Nevertheless, the data could produce some surprises.
NASA has already started looking into the possibility of sending a robotic lander to Europa to follow up on findings from the Europa Clipper mission. Such a lander could sample the ice to a depth of, say, 4 inches (10 centimeters) — and look for signs of life in those samples using a microscope and other lab instruments.