Enceladus Explorer (EnEx) is a planned interplanetary orbiter and lander mission equipped with a subsurface maneuverable ice melting probe suitable to assess the existence of

life Life is a quality that distinguishes matter that has biological processes, such as signaling and self-sustaining processes, from that which does not, and is defined by the capacity for growth, reaction to stimuli, metabolism, energ ...

Saturn Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...

's moon

Enceladus Enceladus is the sixth-largest moon of Saturn (19th largest in the Solar System). It is about in diameter, about a tenth of that of Saturn's largest moon, Titan. Enceladus is mostly covered by fresh, clean ice, making it one of the most refl ...

. The

astrobiology Astrobiology, and the related field of exobiology, is an interdisciplinary scientific field that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology is the multidisciplinary field that investig ...

Enceladus Explorer project is funded by the

German Aerospace Center The German Aerospace Center (german: Deutsches Zentrum für Luft- und Raumfahrt e.V., abbreviated DLR, literally ''German Center for Air- and Space-flight'') is the national center for aerospace, energy and transportation research of Germany ...

(DLR), and is carried out by a research consortium of seven German universities. This collaborative project was started on 22 February 2012.

Concept

is a small icy moon, seemingly similar in chemical makeup to

comet A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...

s, with jets or

geyser A geyser (, ) is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in ...

s of water erupting from its surface that might be connected to active

hydrothermal vent A hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspot ...

s at its subsurface water ocean floor, where the moon's ocean meets the underlying rock, a prime habitat for

. The geysers could provide easy access for sampling the moon's subsurface ocean, and if there is

microbial life A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

in it, ice particles from the sea could contain the evidence astrobiologists need to identify them. Water from the ocean is assumed to upwell through cracks in the ice and then eject into

outer space Outer space, commonly shortened to space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty—it is a near-perfect vacuum containing a low density of particles, pred ...

through the plumes. This water would remain liquid up to shallow depths in the order of even of tens of meters. Enceladus geysers June 2009

The EnEx mission consists of a lander carrying the IceMole, and an orbiter with the main function to act as a communications relay between the lander and Earth. After launch, the lander and orbiter would perform the interplanetary transfer to Saturn together, using the on-board nuclear electric propulsion (NEP) to power electric

ion thruster An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions using electricity. An ion thruster ionizes a neutral gas by extracting some electrons out of a ...

s. The lander would land at a safe distance away from an active vapor plume. The IceMole would then be deployed to melt its way through, while navigating autonomously around hazards, and towards a target subglacial aquiferous fracture at a depth of about for an ''in situ'' examination for the presence of

microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

s before potential

biosignature A biosignature (sometimes called chemical fossil or molecular fossil) is any substance – such as an element, isotope, or molecule – or phenomenon that provides scientific evidence of past or present life. Measurable attribute ...

s and

biomolecules A biomolecule or biological molecule is a loosely used term for molecules present in organisms that are essential to one or more typically biological processes, such as cell division, morphogenesis, or development. Biomolecules include large ...

are degraded by exposure to

. The IceMole has a high energy demand that would be met by a cable run from the lander's small nuclear reactor providing 5 kW of electrical power.

IceMole

The lander would be equipped with the IceMole, an autonomous and maneuverable melting ice probe for clean ''in situ'' analysis and sampling of glacial ice and subglacial materials, including a liquid sample from a water reservoir below the icy crust. The design is based on combining melting and mechanical propulsion. They demonstrated downward, horizontal and upward melting, as well as curve driving and dirt layer penetration. It offers systems for obstacle avoidance, target detection, and acoustic navigation in ice.

References

External links

Enceladus Explorer homepage
*Video
Presentation at the Habitability of Icy Worlds Workshop
including information on EnEx (February 2014). {{DEFAULTSORT:Enceladus Explorer Proposed astrobiology space missions Enceladus Missions to Saturn Orbiters (space probe) Proposed space probes

Concept

IceMole

See also

References

External links