Above, you are viewing activities from High Bay 1 at JPL. The large aluminum cylinder visible on the left is Europa Clipper’s main body. Standing 10 feet (3 meters) tall and 5 feet (1.5 meters) wide, the main body is integrated with electronics, radios, thermal loop tubing, cabling, and the spacecraft’s propulsion system. The aluminum box visible on the right is Europa Clipper’s vault, which will shield electronics to reduce the impact of radiation. Additional Europa Clipper assembly operations are taking place in clean rooms across JPL and at partner institutions across the United States.

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NASA’s Europa Clipper spacecraft will launch in October 2024 on a mission to determine if Jupiter’s moon Europa could support life below its icy surface. When fully assembled, Europa Clipper will be as large as a passenger van, with solar arrays long enough to span a basketball court—more than 100 feet (30 meters). Nearly every detail of the spacecraft is being handcrafted to enable the acquisition of this unprecedented science.

Assembly is now underway in “clean rooms” at NASA’s Jet Propulsion Laboratory (JPL) in Southern California, with engineering components and science instruments streaming in from across the United States and even Europe. This important step is part of the Assembly, Test, and Launch Operations (or “ATLO”) phase of the spacecraft’s development. During this phase, engineers will put together the spacecraft, test its various components, and then launch it into space.

Here’s what you need to know about how Europa Clipper will come together.

Hardware for Europa Clipper is developed at JPL and at partner institutions and contractor facilities across the United States and Europe. This includes the nine science instruments and other spacecraft components, such as the propulsion module, radiofrequency module, solar arrays, star trackers, electronics vault, and more. The instruments and components are developed, tested, and prepared for shipping to JPL.

The start of the second phase marks the official start of ATLO. Engineers prepare the work spaces they will need to assemble and test Europa Clipper hardware at JPL. They make laboratory spaces ready, including “clean rooms”—spacecraft assembly facilities where dust and static electricity are kept at extremely low levels, because they can interfere with or damage spacecraft hardware. These clean rooms are also important because they help us prevent the contamination of worlds relevant to the search for life by microbes from Earth.

Instruments and other spacecraft hardware arrive. Electrical support equipment is brought online, mechanical cabling is put in place, and instrumentation testing procedures are worked through. Up to this point hardware for spacecraft instruments and subsystems are tested at the component level—in other words, they have not yet been assembled into their final configuration.

Now Europa Clipper begins to take shape. Hardware has arrived, undergone testing, and is assembled by stacking pieces into what looks like a spacecraft. While the second phase of ATLO is focused on integration and testing prior to assembly, this third step is focused on system-level tests of the assembled configuration, including the software systems that will be used to fly the spacecraft.

To reach Europa, the spacecraft must survive liftoff, the heat of the Sun, the cold of distant space, micrometeriorites, and the radiation environment of Jupiter. Tests are conducted to demonstrate that the spacecraft can survive the environments it will experience in flight. That includes vibration tests—ensuring Europa Clipper and its components can withstand the stress and shaking during launch—and placing the spacecraft in a vacuum chamber as well as a space-Sun simulator. Many of these tests will take place in special buildings designed for environmental testing at JPL.

After environmental tests, Europa Clipper will be brought back to its assembly facilities for a thorough checkout, to make sure everything is still working correctly. All the instruments must be properly aligned and the spacecraft prepared for shipment to the launch site. This phase includes some disassembly—for example, the high-gain antenna and solar arrays are removed and crated separately. Support equipment for launch also must be shipped. Some will be transported by truck, while other components will be flown to the launch site.

Europa Clipper will launch from Kennedy Space Center (KSC) in Florida in October 2024. The arrival of the spacecraft and associated equipment at KSC marks the start of the final phase of ATLO. The support equipment is unpacked, and the spacecraft is reassembled. Cables are laid out, and more baseline tests are conducted to ensure none of the systems were disturbed during shipment. Final checkouts are performed, the spacecraft is fueled, and then it goes to spacecraft integration with the launch vehicle. The rocket, joined with its payload, is rolled out to the launchpad. The countdown and ensuing launch mark the final steps of ATLO.

Want to learn more about the Europa Clipper spacecraft? Build your own version of Europa Clipper at home! Snap a photo of your model and share it on social media using the hashtag #EuropaClipper.​

Europa Clipper’s paper model is appropriate for students in grades 5+. Download the kit here.

Create your own 3D printed model of the Europa Clipper spacecraft. Download the file here.

NASA Official/Program Executive: Dave Lavery NASA Official/Program Scientist: Curt Niebur Public Engagement Lead: Laurance Fauconnet Public Engagement Manager: Heather Doyle Science Writer: Jay R. Thompson Media Contact: Gretchen McCartney