Technicians in a clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland, check the fit of the upper and lower cylinders of the propulsion module core of NASA's Europa Clipper spacecraft on Oct. 15, 2020. The stacked cylinders stand almost 10 feet (3 meters) high and hold the propulsion tanks and rocket engines that will propel Europa Clipper once it leaves Earth's atmosphere on its path toward Jupiter's moon Europa. In this photo, the cylinders are stacked atop an adapter ring that's about 1 foot (0.3 meters) high.

The cylinders were built by the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. They were shipped to NASA's Jet Propulsion Laboratory in Southern California for installation of the Heat Redistribution System (HRS) tubing, which helps control the spacecraft's temperature. The cylinders were then shipped to Goddard for the propulsion subsystem installation.

With an internal global ocean twice the size of Earth's oceans combined, Europa may have the potential to harbor life. The Europa Clipper orbiter will swoop around Jupiter on an elliptical path, dipping close to the moon on each flyby to collect data. Understanding Europa's habitability will help scientists better understand how life developed on Earth and the potential for finding life beyond our planet. Europa Clipper is aiming for a launch readiness date of 2024.

More information about Europa and Europa Clipper can be found here: europa.nasa.gov.