Painting of the NASA logo, also called the meatball, continues on the 525-foot-tall Vehicle Assembly Build ing (VAB) at the agency鈥檚 Kennedy Space Center in Florida on June 23, 2020. 鈥 NASA/BEN SMEGELSKY

WASHINGTON 鈥 The National Aeronautics and Space Administration (NASA) is set to launch a spacecraft to Jupiter鈥檚 moon Europa, considered one of our solar system鈥檚 most promising spots to search for life beyond Earth, to learn whether this ice-encased world believed to harbor a vast underground ocean is habitable.

The US space agency鈥檚 robotic solar-powered Europa Clipper spacecraft will be launched on a SpaceX Falcon Heavy rocket from the Kennedy Space Center in Cape Canaveral, carrying nine scientific instruments. After traveling 1.8 billion miles (2.9 billion km) in a trip lasting about 5-1/2 years, Europa Clipper is due to enter orbit around Jupiter in 2030.

After a delay caused by Hurricane Milton, NASA set a tentative launch time for 12:06 p.m. ET (1606 GMT) on Monday.

Scientists have a keen interest in the salty liquid water ocean that previous observations have indicated resides below Europa鈥檚 icy shell.

鈥淭here is very strong evidence that the ingredients for life exist on Europa. But we have to go there to find out,鈥 said planetary scientist Bonnie Buratti of NASA鈥檚 Jet Propulsion Laboratory, the mission鈥檚 deputy project scientist.

鈥淛ust to emphasize: we鈥檙e not a life-detection mission. We鈥檙e just looking for the conditions for life,鈥 Ms. Buratti added.

Europa Clipper is the biggest spacecraft NASA has ever built for a planetary mission, measuring about 100 feet (30.5 meters) long, about 58 feet (17.6 meters) wide and weighing approximately 13,000 pounds (6,000 kg). It is larger than a basketball court because of its sizable solar arrays to gather sunlight for powering scientific instruments, electronics and its other subsystems.

The spacecraft is due to fly by Mars, then back by Earth, using the gravity of each planet to increase its momentum like a slingshot. It has three main science objectives: gauging the thickness of Europa鈥檚 outer layer of ice and its interactions with the subsurface below, figuring out the moon鈥檚 composition, and determining its geology.

NASA is planning for its spacecraft to conduct 49 close flybys of Europa over a span of three years.

Europa鈥檚 diameter is about 1,940 miles (3,100 km) at its equator, roughly 90% that of our moon. Europa鈥檚 icy shell is currently believed to be 10-15 miles (15-25 km) thick, floating atop an ocean 40-100 miles (60-150 km) deep.

AN OCEAN WORLD
This moon is considered an 鈥渙cean world.鈥 Even though Europa is just a quarter of Earth鈥檚 diameter, its subsurface ocean may contain twice the water in Earth鈥檚 oceans.

鈥淎s an ocean world, Europa is very intriguing. And this mission is going to help us to understand a complex piece of our solar system,鈥 said Gina DiBraccio, acting director of NASA鈥檚 planetary science division.

Ocean worlds, Ms. DiBraccio said, might be a common type of body outside our solar system.

鈥淐lipper is going to be the first in-depth mission that will allow us to characterize habitability on what could be the most common type of inhabited world in our universe,鈥 Ms. DiBraccio said.

Despite its hostile and frigid surface, scientists believe Europa could be capable of nurturing life. Ms. Buratti noted that there are three main requirements for life to form: liquid water, certain chemistry 鈥 specifically organic compounds that could serve as food for any primitive organisms 鈥 and an energy source.

Europa receives only about 4% of the solar radiation that Earth 鈥 five times closer to the sun 鈥 gets. But Ms. Buratti noted that Europa flexes as its orbit comes nearer and farther from Jupiter, thanks to the huge planet鈥檚 strong gravitational pull 鈥 a process that produces heat on the moon.

鈥淭hat鈥檚 the source of energy we have,鈥 Ms. Buratti said.

At the bottom of Europa鈥檚 ocean, where the water meets the rocky mantle, there may be thermal vents where heat releases chemical energy.

鈥淭hey may be similar to thermal vents in the deep oceans of the Earth where primitive life exists and where life may have originated on the Earth,鈥 Ms. Buratti said.

The spacecraft鈥檚 MASPEX instrument will sample gases to study Europa鈥檚 ocean, surface and atmospheric chemistries. MASPEX will look for 鈥渟ophisticated organic molecules that could provide the food, if there are any primitive organisms,鈥 Ms. Buratti added.

Jupiter is our solar system鈥檚 largest planet. Among its 95 officially recognized moons, Europa is fourth largest, behind Ganymede, Callisto and Io. Europa orbits about 417,000 miles (671,000 km) from Jupiter.

Ms. Buratti said exploratory missions like this one always uncover something 鈥渢hat we could not have imagined.鈥

鈥淭here is going to be something there 鈥 the unknown 鈥 that is going to be so wonderful that we can鈥檛 conceive of it right now,鈥 Ms. Buratti said. 鈥淭hat鈥檚 the thing that excites me most.鈥 鈥 Reuters