PIA19656-SaturnMoon-Enceladus-Ocean-ArtConcept-20150915

PIA17655 crop Titan north polar seas and lakes

Explorer of Enceladus and Titan (E²T) is a space mission concept that would investigate the evolution and

habitability Habitability refers to the adequacy of an environment for human living. Where housing is concerned, there are generally local ordinances which define habitability. If a residence complies with those laws it is said to be habitable. In extreme e ...

of the Saturnian satellites

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 ...

and

Titan Titan most often refers to: * Titan (moon), the largest moon of Saturn * Titans, a race of deities in Greek mythology Titan or Titans may also refer to: Arts and entertainment Fictional entities Fictional locations * Titan in fiction, fictiona ...

and is proposed by the

European Space Agency , owners = , headquarters = Paris, Île-de-France, France , coordinates = , spaceport = Guiana Space Centre , seal = File:ESA emblem seal.png , seal_size = 130px , image = Views in the Main Control Room (1205 ...

in collaboration with

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

. The proposed mission would address key scientific questions regarding extraterrestrial habitability, abiotic/prebiotic chemistry and emergence of life, which are among the highest priorities of ESA's

Cosmic Vision Cosmic Vision is the third campaign of space science and space exploration missions in the Science Programme of the European Space Agency (ESA). Formulated in 2005 as ''Cosmic Vision: Space Science for Europe 2015–2025'', the campaign succee ...

program.

Overview

The Explorer of Enceladus and Titan (E²T) orbiter was first proposed in 2017 as a medium-class mission led by the

in collaboration with

in response to ESA's M5

programme. Both Enceladus and Titan harbour subsurface oceans that are prime environments in which to investigate the conditions for the emergence of life and the habitability potential of ocean worlds as well as the origin and evolution of unique complex planetary systems.

Goals

The E²T mission has three scientific goals: *Investigate the origin and evolution of volatile-rich icy worlds by examining both Enceladus and Titan *Investigate the

and potential for

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 ...

in ocean worlds on both Enceladus and Titan *Investigate Titan as an Earth-like world with an evolving climate and landscape. These goals would be accomplished by measuring the nature, abundance and isotopic properties of solid- and vapor-phase species in Enceladus' plume and Titan's upper atmosphere.

Conceptual payload

The payload would provide ''in-situ'' sampling, high-resolution imaging and radio science measurements from multiple flybys of Enceladus and Titan using a solar-electric powered spacecraft in orbit around

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 ...

. The two main instruments proposed are the Ion and Neutral Gas Mass Spectrometer (INMS) and the Enceladus Icy Jet Analyzer (ENIJA); these high resolution

mass spectrometer Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used ...

s would provide the data needed to discern the subtle details of the aqueous environment of Enceladus from plume sampling and of the complex pre-biotic chemistry occurring in Titan's atmosphere. The Titan Imaging and Geology, Enceladus Reconnaissance (TIGER) mid-wave

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

camera would map thermal emission from the plumes and Enceladus' tiger stripes at meter scales and investigate Titan's geomorphology at 50–100 m resolution. The Radio Science Experiment (RSE) measurements would provide constraints on the ice shell structure and the properties of the internal oceans of Enceladus and Titan.

Propulsion

The spacecraft concept calls for using an

ion drive 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 ...

propulsion, proven to be extremely efficient and reliable. An ion thruster —or ion drive— is a form of

electric propulsion Spacecraft electric propulsion (or just electric propulsion) is a type of spacecraft propulsion technique that uses electrostatic or electromagnetic fields to accelerate mass to high speed and thus generate thrust to modify the velocity of a sp ...

that creates

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that syst ...

by accelerating

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

s with

electricity Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...

. The required electricity is generated by

solar panels A solar cell panel, solar electric panel, photo-voltaic (PV) module, PV panel or solar panel is an assembly of photovoltaic solar cells mounted in a (usually rectangular) frame, and a neatly organised collection of PV panels is called a phot ...

mounted on the spacecraft.

References

External links