The Europa Jupiter System Mission – Laplace (EJSM-Laplace) was a proposed joint
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, succeedi ...
/
ESA
, 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 (1 ...
uncrewed space mission
Spaceflight (or space flight) is an application of astronautics to fly spacecraft into or through outer space, either with or without humans on board. Most spaceflight is uncrewed and conducted mainly with spacecraft such as satellites in or ...
slated to launch around 2020 for the in-depth exploration of
Jupiter's moons
There are 82 known moons of Jupiter, not counting a number of moonlets likely shed from the inner moons. All together, they form a satellite system which is called the Jovian system. The most massive of the moons are the four Galilean moons: ...
with a focus on
Europa,
Ganymede and Jupiter's
magnetosphere
In astronomy and planetary science, a magnetosphere is a region of space surrounding an astronomical object in which charged particles are affected by that object's magnetic field. It is created by a celestial body with an active interior dynamo ...
. The mission would have comprised at least two independent elements, NASA's
Jupiter Europa Orbiter (JEO) and ESA's
Jupiter Ganymede Orbiter (JGO), to perform coordinated studies of the Jovian system.
The Japan Aerospace Exploration Agency (
JAXA
The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into o ...
) and the
Roscosmos
The State Space Corporation "Roscosmos" (russian: Государственная корпорация по космической деятельности «Роскосмос»), commonly known simply as Roscosmos (russian: Роскосмос) ...
(Russian Space Agency) had expressed their interest in contributing to EJSM-Laplace, although no deals had been finalized. JEO was estimated to cost US$4.7 billion, while ESA would spend US$1.0 billion (€710 million) on JGO.
In April 2011, European Space Agency (ESA) stated that it seemed unlikely that a joint US–European mission will happen in the early 2020s given NASA's budget, so ESA continued with its initiative, called the
Jupiter Icy Moons Explorer
The Jupiter Icy Moons Explorer (JUICE) is an interplanetary spacecraft in development by the European Space Agency (ESA) with Airbus Defence and Space as the main contractor. The mission will study three of Jupiter's Galilean moons: Ganymede ...
(JUICE) that will be based on the JGO design. Selection of JUICE for the L1 launch slot 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 ...
science programme was announced on 2 May 2012.
Later, in June 2015, NASA approved the ''
Europa Clipper
Europa Clipper (previously known as Europa Multiple Flyby Mission) is an interplanetary mission in development by NASA comprising an orbiter. Planned for launch in October 2024, the spacecraft is being developed to study the Galilean moon Eu ...
'' and it entered the formulation stage, with an expected launch between 2022-2025.
Origins
In February 2008,
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, succeedi ...
and
ESA
, 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 (1 ...
began joint investigations into sending a probe to study the icy satellites of the outer
Solar System
The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...
under the title
Outer Planet Flagship Mission
NASA's large strategic science missions or large strategic missions, formerly known as Flagship missions or Flagship-class missions, are the costliest and most capable NASA science spacecraft. Flagship missions exist within all four divisions ...
. Two primary candidate missions were considered under the study: EJSM and
Titan Saturn System Mission
Titan Saturn System Mission (TSSM) was a joint NASA–ESA proposal for an exploration of Saturn and its moons Titan and Enceladus, where many complex phenomena were revealed by '' Cassini''. TSSM was proposed to launch in 2020, get gravity assis ...
(TSSM), also known under the ESA designation TandEM.
In February 2009, it was announced that NASA/ESA had given EJSM priority ahead of the TSSM.
The ESA contribution still faced funding competition from two other missions, the
Laser Interferometer Space Antenna
The Laser Interferometer Space Antenna (LISA) is a proposed space probe to detect and accurately measure gravitational waves—tiny ripples in the fabric of spacetime—from astronomical sources. LISA would be the first dedicated space-based ...
(LISA) and the
International X-ray Observatory (IXO), which is why NASA kept a contingency plan of sending its part of the mission as a stand-alone project.
Mission architecture

The most distinctive feature of the EJSM/Laplace-study, was the proposed collaboration with multiple orbiters and landers:
*
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, succeedi ...
:
Jupiter Europa Orbiter (JEO), proposed to study
Europa and
Io.
*
ESA
, 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 (1 ...
:
Jupiter Ganymede Orbiter (JGO), proposed to study
Ganymede and
Callisto Callisto most commonly refers to:
* Callisto (mythology), a nymph
*Callisto (moon), a moon of Jupiter
Callisto may also refer to:
Art and entertainment
*'' Callisto series'', a sequence of novels by Lin Carter
*''Callisto'', a novel by Torsten ...
*
JAXA
The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into o ...
:
Jupiter Magnetospheric Orbiter (JMO), proposed to study
Jupiter
Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandt ...
's
magnetosphere
In astronomy and planetary science, a magnetosphere is a region of space surrounding an astronomical object in which charged particles are affected by that object's magnetic field. It is created by a celestial body with an active interior dynamo ...
.
*
JAXA
The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into o ...
:
Jupiter and Trojan Asteroid Explorer (JTAX), proposed to study a
Jupiter trojan
The Jupiter trojans, commonly called trojan asteroids or simply trojans, are a large group of asteroids that share the planet Jupiter's orbit around the Sun. Relative to Jupiter, each trojan librates around one of Jupiter's stable Lagrange p ...
.
The baseline EJSM architecture consisted of JEO and JGO, which were proposed to be launched in 2020 and explore the Jupiter System before settling into orbit around Europa and Ganymede, respectively. The JEO and JGO were separate and independent spacecraft developed, launched and operated by their respective organizations to work together. Their launch dates and interplanetary trajectories were not to be dependent on each other, but would have been synergistic.
[ ]
Goal
The goal was to determine whether the Jupiter system harbors
habitable environments, while focusing on
Europa and
Ganymede. The main science objectives supporting this goal were:
* Characterize sub-surface oceans
* Characterize the ice shells and any subsurface water
* Characterize the deep internal structure for Ganymede and the intrinsic magnetic field
* Compare the
exosphere
The exosphere ( grc, ἔξω "outside, external, beyond", grc, σφαῖρα "sphere") is a thin, atmosphere-like volume surrounding a planet or natural satellite where molecules are gravitationally bound to that body, but where the densit ...
s,
plasma environments, and magnetospheric interactions.
* Determine global surface compositions and chemistry
* Understand the formation of surface features, including sites of recent or current activity, and identify and characterize candidate sites for future ''in situ'' exploration.
References
External links
EJSM-Laplaceat nasa.gov
EJSM-Laplaceat esa.int
Joint NASA/ESA report on the Laplace/EJSM mission*
"Jupiter Ganymede Orbiter: ESA contribution to the Europe Jupiter System Mission"by European Space Agency
*
"Jupiter Europa Orbiter Mission Study 2008: Final Report"by NASA
*
{{DEFAULTSORT:Europa Jupiter System Mission - Laplace
European Space Agency space probes
NASA programs
Cancelled NASA space probes
Cancelled space probes
Missions to Jupiter