The Europa Jupiter System Mission – Laplace (EJSM-Laplace) was a proposed joint

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

/ ESA uncrewed space mission slated to launch around 2020 for the in-depth exploration of Jupiter's 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 (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 (JUICE) that will be based on the JGO design. Selection of JUICE for the L1 launch slot of ESA's Cosmic Vision science programme was announced on 2 May 2012. JUICE was launched on 14 April 2023. Later, in June 2015, NASA approved the '' Europa Clipper'', which was launched on 14 October 2024.

Origins

In February 2008,

and ESA began joint investigations into sending a probe to study the icy satellites of the outer

Solar System The Solar SystemCapitalization 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 "Sola ...

under the title Outer Planet Flagship Mission. Two primary candidate missions were considered under the study: EJSM and Titan Saturn System Mission (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 (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: *

: Jupiter Europa Orbiter (JEO), proposed to study Europa and Io. * ESA: Jupiter Ganymede Orbiter (JGO), proposed to study Ganymede and Callisto *

: Jupiter Magnetospheric Orbiter (JMO), proposed to study

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined a ...

. *

: Jupiter and Trojan Asteroid Explorer (JTAX), proposed to study a Jupiter trojan. 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 is a thin, atmosphere-like volume surrounding a planet or natural satellite where molecules are gravitationally bound to that body, but where the density is so low that the molecules are essentially collision-less. In the case of ...

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-Laplace
at nasa.gov
EJSM-Laplace
at 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