Mission…

VIVA – In 2024, NASA will launch Europa Clipper, a long-awaited orbiter mission that will fly to Jupiter (arriving in 2030) to explore its icy moon, Europa.

Through a series of flybys, the Clipper will survey the surface and activity of Europa’s plumes in the hope of finding organic molecules and other potential indications of life (“biosignatures”).

If all goes well, NASA plans to send a follow-up mission to land on the surface and examine Europa’s ice layers and plumes more closely. This proposed mission is named Europa Lander.

Although a date has not been set and the mission is still in the research phase, several significant steps have been taken to bring the Europa Lander to the development stage.

Last August, engineers at NASA’s Jet Propulsion Laboratory (JPL) in Southern California tested a prototype of this proposed landing system in a simulated environment.

The system combines hardware used by previous NASA lander missions and several new elements that make missions to Europa possible. It could also be adapted to facilitate missions to more “Ocean Worlds” and other celestial bodies in our Solar System.

Since the 1970s, when NASA’s Voyager 1 and 2 probes flew past Jupiter and its moon system, scientists have been eager to get a closer look at Europa. Several missions have visited Jupiter since then, including the NASA-ESA Ulysses space probe, which flew past the system in 1992 and 2004.

This was followed by the Cassini–Huygens probe flyby in 2000 on its way to Saturn and the New Horizons mission. that buzzed the system on its way to the Trans-Neptunian region. However, only two missions have traveled to the system and remained there to study Jupiter and its satellites: the Galileo space probe (1995-2003) and Juno (2016-present).

Thanks to data obtained from the Voyager probe, scientists have begun to speculate that there may be a liquid ocean beneath Europa’s ice sheet. Using planetary models, they further theorized that Europa (and the other Galilean moons) experiences tidal flexure in its interior due to interactions with Jupiter’s strong gravity.

This, they speculate, could have led to hydrothermal activity at the moon’s core-mantle boundary, providing the heat and chemical energy necessary for life. Later missions further confirmed these suspicions by detecting plume activity, carbon dioxide, and mineral salts on the lunar surface.

Creating a Europa Lander that can navigate challenging terrain required an advanced approach, which NASA engineers addressed by adapting elements that have worked in the past.

This includes the architecture used for the “sky crane” landing systems used by NASA’s Curiosity and Perseverance rovers, which rely on parachutes and retro rockets to slow their descent and a pulley system to lower them to the surface.

JPL engineers created a simulated propulsive descent stage for their prototype that kept the Europa Lander stable as four harnesses lowered it. The lander has four legs, each of which has a four-rod connecting mechanism that controls the pose of the legs before and during landing.

Each foot is loaded down with a constant force spring to help them reset and press against any surface they encounter as they slowly land on the surface.

This allows the feet to passively adjust to whatever terrain they encounter while providing extra traction and stability during and after the landing event.

The bottom of the Lander has a belly pan (similar to a skid plate on a car) that resists movement and protects the Lander from potentially dangerous terrain. Once the abdomen touches the surface, sensors trigger a mechanism that locks the leg swivel joints.

At this point, the legs are responsible for maintaining stability and maintaining the lander’s height when the harness is released. If the belly pan does not encounter terrain during touchdownsensors on each leg can also state touchdown. In this case, the belly pan would be suspended above the terrain, and the Lander would be supported only by its four legs.

What was not filmed was the phase after the bridle was released, which consisted of cutting the bridle and the drifting booster stage flying away. Although this landing architecture was developed with Europa in mind, it can be adapted for use on the moon and other celestial bodies with challenging terrain.

This will be useful when NASA and other space agencies consider sending missions to other “Ocean Worlds” in the Solar System that also have oceans beneath their ice layers (and may harbor life within them).

Meanwhile, scientists are eagerly awaiting the arrival of ESA’s JUpiter ICy moon Explorer (JUICE) mission, which launches from the European Spaceport in French Guiana on April 14, 2023.

When it arrives at Jupiter in July 2031, the mission will spend the next three months and half a year primarily studying Callisto, Ganymede, and Europa, the three Galilean moons thought to have inner oceans.

Europa Clipper is scheduled to launch on October 10, 2024, and will arrive in the Jupiter system in April 2030, sooner than JUICE. The data provided by this orbiter mission will pave the way for the Europa Lander mission, which will include surface analysis, monitoring of plume activity, and selection of landing sites as well as potential science objectives.