Europa Clipper Explained

Europa Clipper (previously known as Europa Multiple Flyby Mission) is a space probe developed by NASA to study Europa, a Galilean moon of Jupiter. It was launched on October 14, 2024.^[13] The spacecraft will use gravity assists from Mars on March 1, 2025,^[8] and Earth on December 3, 2026,^[9] before arriving at Europa in April 2030.^[14] The spacecraft will then perform a series of flybys of Europa while in orbit around Jupiter.^{[15] [16]}

Europa Clipper is designed to follow up on evidence for a subsurface ocean underneath Europa's ice crust, found using the Galileo spacecraft which orbited Jupiter from 1995 to 2003. Plans to send a spacecraft to Europa were initially conceived with projects such as Europa Orbiter and Jupiter Icy Moons Orbiter, in which a spacecraft would be inserted into orbit around Europa. However, due to the adverse effects of radiation from the magnetosphere of Jupiter in Europa orbit, it was decided that it would be safer to insert a spacecraft into an elliptical orbit around Jupiter and make 49 close flybys of the moon instead.^[17] The Europa Clipper spacecraft is larger than any other used for previous NASA planetary missions.^[18]

Europa Clipper complements the European Space Agency's Jupiter Icy Moons Explorer, launched in 2023, which will attempt to fly past Europa twice and Callisto multiple times before moving into orbit around Ganymede.

History

In 1997, a Europa Orbiter mission was proposed by a team for NASA's Discovery Program^[19] but was not selected. NASA's JPL announced one month after the selection of Discovery proposals that a NASA Europa orbiter mission would be conducted. JPL then invited the Discovery proposal team to be the Mission Review Committee (MRC).

At the same time as the proposal of the Discovery-class Europa Orbiter, the robotic Galileo spacecraft was already orbiting Jupiter. From December 8, 1995, to December 7, 1997, Galileo conducted the primary mission after entering the orbit of Jupiter. On that final date, the Galileo orbiter commenced an extended mission known as the Galileo Europa Mission (GEM), which ran until December 31, 1999. This was a low-cost mission extension with a budget of only US$30 million. The smaller team of about 40–50 people (compared with the primary mission's 200-person team from 1995 to 1997) did not have the resources to deal with problems, but when they arose, it was able to temporarily recall former team members (called "tiger teams") for intensive efforts to solve them. The spacecraft made several flybys of Europa (8), Callisto (4) and Io (2). On each flyby of the three moons it encountered, the spacecraft collected only two days' worth of data instead of the seven it had collected during the primary mission. During GEM's eight flybys of Europa, it ranged from 196to, in two years.^[20]

Europa has been identified as one of the locations in the Solar System that could possibly harbor microbial extraterrestrial life.^{[21] [22] [23]} Immediately following the Galileo spacecraft's discoveries and the independent Discovery program proposal for a Europa orbiter, JPL conducted preliminary mission studies that envisioned a capable spacecraft such as the Jupiter Icy Moons Orbiter (a US$16 billion mission concept),^[24] the Jupiter Europa Orbiter (a US$4.3 billion concept), another orbiter (US$2 billion concept), and a multi-flyby spacecraft: Europa Clipper.

A mission to Europa was recommended by the National Research Council in 2013. The approximate cost estimate rose from US$2 billion in 2013 to US$4.25 billion in 2020.^{[25] [26]} The mission is a joint project between the Johns Hopkins University's Applied Physics Laboratory (APL), and the Jet Propulsion Laboratory (JPL).^[27] The mission's name is a reference to the lightweight clipper ships of the 19th century that routinely plied trade routes around the world.^[28] The moniker was chosen because the spacecraft will sail past Europa, as frequently as every two weeks.

In March 2013, US$75 million was authorized to expand on the formulation of mission activities, mature the proposed science goals, and fund preliminary instrument development,^[29] as suggested in 2011 by the Planetary Science Decadal Survey.^[30] In May 2014, a House bill substantially increased the Europa Clipper (referred to as Europa Multiple Flyby Mission) funding budget for the 2014 fiscal year from US$15 million^{[31] [32]} to US$100 million to be applied to pre-formulation work.^{[33] [34]} Following the 2014 election cycle, bipartisan support was pledged to continue funding for the Europa Multiple Flyby Mission project.^{[35] [36]} The executive branch also granted US$30 million for preliminary studies.^{[37] [38]}

In April 2015, NASA invited the European Space Agency to submit concepts for an additional probe to fly together with the Europa Clipper spacecraft, with a mass limit of 250 kg.^[39] It could be a simple probe, an impactor,^[40] or a lander.^[41] An internal assessment at European Space Agency (ESA) considered whether there was interest and funds available,^{[42] [43] [44] [45]} opening a collaboration scheme similar to the very successful Cassini–Huygens approach. In May 2015, NASA chose nine instruments that would fly on board the orbiter, budgeted to cost about US$110 million over the next three years.^[46] In June 2015, NASA approved the mission concept, allowing the orbiter to move to its formulation stage.^[47] In January 2016, NASA approved the addition of a lander,^{[48] [49]} but this was canceled in 2017 because it was deemed too risky.^[50] In May 2016, the Ocean Worlds Exploration Program was approved,^[51] of which the Europa mission is part.^[52]

In February 2017, the mission moved from Phase A to Phase B (the preliminary design phase).^[53] On July 18, 2017, the House Space Subcommittee held hearings on the Europa Clipper as a scheduled Large Strategic Science Missions class, and to discuss a possible follow up mission simply known as the Europa Lander. Phase B continued into 2019. In addition, subsystem vendors were selected, as well as prototype hardware elements for the science instruments. Spacecraft sub-assemblies were built and tested as well.

In July 2024, the spacecraft faced concerns of delay and missing the launch window because of a discovery in June 2024 that its components were not as radiation-hardened as previously believed.^[54] However, over the summer, intensive re-testing of the transistor components in question found that they would likely be annealed enough to 'self-heal'.^[55] In September 2024, Europa Clipper was approved for a launch window opening on October 10, 2024;^{[56] [57] [55]} however, on October 6, 2024, NASA announced that it would be standing down from the October 10 launch due to Hurricane Milton. Europa Clipper was finally launched on October 14, 2024.^[58]

Fabrication and assembly

On August 19, 2019, the Europa Clipper proceeded to Phase C: final design and fabrication.^[59]

On March 3, 2022, the spacecraft moved on to Phase D: assembly, testing, and launch.^[60] On June 7, 2022, the main body of the spacecraft was completed.^[61] By August 2022, the high-gain antenna had completed its major testing campaigns.

By January 30, 2024, all of the science instruments were added to the spacecraft. The REASON instrument's electronics were aboard the spacecraft, while its antennas were added to the spacecraft's solar arrays at Kennedy Space Center later in the year.^[62] In March 2024, it was reported that the spacecraft underwent successful testing and was on track for launch later in the year.^[63] In May 2024, the spacecraft arrived at Kennedy Space Center for final launch preparations.^[64] In September 2024, final pre-launch review was successfully completed, clearing the way for launch.^[65] In early October 2024, due to the incoming Hurricane Milton, the spacecraft was placed in secure storage for safekeeping until the hurricane passed.^[58]

End of mission planning

The probe is scheduled to be crashed into Jupiter, Ganymede, or Callisto, to protect it from crashing into Europa. In June 2022, lead project scientist Robert Pappalardo revealed that mission planners for Europa Clipper were considering disposing of the probe by crashing it into the surface of Ganymede in case an extended mission was not approved early in the main science phase. He noted that an impact would help the ESA's JUICE mission collect more information about Ganymede's surface chemistry.^{[66] [67]} In a 2024 paper, Pappalardo said the mission would last four years in Jupiter orbit, and that the disposal was targeted for September 3, 2034, if NASA did not approve a mission extension.^[68]

Objectives

The goals of Europa Clipper are to explore Europa, investigate its habitability and aid in the selection of a landing site for the proposed Europa Lander.^[69] This exploration is focused on understanding the three main requirements for life: liquid water, chemistry, and energy.^[70] Specifically, the objectives are to study:

• Ice shell and ocean: Confirm the existence and characterize the nature of water within or beneath the ice, and study processes of surface-ice-ocean exchange.
• Composition: Distribution and chemistry of key compounds and the links to ocean composition.
• Geology: Characteristics and formation of surface features, including sites of recent or current activity.

Strategy

Because Europa lies well within the harsh radiation fields surrounding Jupiter, even a radiation-hardened spacecraft in near orbit would be functional for just a few months.^[71] Most instruments can gather data far faster than the communications system can transmit it to Earth due to the limited number of antennas available on Earth to receive the scientific data. Therefore, another key limiting factor on science for a Europa orbiter is the time available to return data to Earth. In contrast, the amount of time during which the instruments can make close-up observations is less important.

Studies by scientists from the Jet Propulsion Laboratory show that by performing several flybys with many months to return data, the Europa Clipper concept will enable a US$2 billion mission to conduct the most crucial measurements of the canceled US$4.3 billion Jupiter Europa Orbiter concept. Between each of the flybys, the spacecraft will have seven to ten days to transmit data stored during each brief encounter. That will let the spacecraft have up to a year of time to transmit its data compared to just 30 days for an orbiter. The result will be almost three times as much data returned to Earth, while reducing exposure to radiation. Europa Clipper will not orbit Europa, but will instead orbit Jupiter and conduct 44 flybys of Europa, each at altitudes ranging from 25 km to 2,700 km (16 mi to 1,678 mi) during its 3.5-year mission.^{[72] [73]} A key feature of the mission concept is that Europa Clipper would use gravity assists from Europa, Ganymede and Callisto to change its trajectory, allowing the spacecraft to return to a different close approach point with each flyby. Each flyby would cover a different sector of Europa to achieve a medium-quality global topographic survey, including ice thickness.^[74] Europa Clipper could conceivably fly by at low altitude through the plumes of water vapor erupting from the moon's ice crust, thus sampling its subsurface ocean without having to land on the surface and drill through the ice.

The spacecraft is expected to receive a total ionizing dose of 2.8Mrad during the mission. Shielding from Jupiter's harsh radiation belt will be provided by a radiation vault with 0.3inches thick aluminum alloy walls, which enclose the spacecraft electronics.^[75] To maximize the effectiveness of this shielding, the electronics are also nested in the core of the spacecraft for additional radiation protection.

Design and construction

This mission is a flight of NASA's Planetary Science Division, designated a Large Strategic Science Mission, and funded under the Planetary Missions Program Office's Solar System Exploration program as its second flight.^{[76] [77]} It is also supported by the new Ocean Worlds Exploration Program.^[52]

The spacecraft bus is a 5-meter-long combination of a 150-cm-wide aluminum cylindrical propulsion module and a rectangular box. The electronic components are protected from the intense radiation by a 150-kilogram titanium, zinc and aluminum shielded vault in the box. The spacecraft payload and trajectory are subject to change as the mission design matures.^[78]

Power

Both radioisotope thermoelectric generator (RTG) and photovoltaic power sources were assessed to power the orbiter.^[79] Although solar power is only 4% as intense at Jupiter as it is in Earth's orbit, powering a Jupiter orbital spacecraft by solar panels was demonstrated by the Juno mission. The alternative to solar panels was a multi-mission radioisotope thermoelectric generator (MMRTG), fueled with plutonium-238. The power source has already been demonstrated in the Mars Science Laboratory (MSL) mission. Five units were available, with one reserved for the Mars 2020 rover mission and another as backup. In September 2013, it was decided that the solar array was the less expensive option to power the spacecraft, and on October 3, 2014, it was announced that solar panels were chosen to power Europa Clipper. The mission's designers determined that solar power was both cheaper than plutonium and practical to use on the spacecraft. Despite the increased weight of solar panels compared to plutonium-powered generators, the vehicle's mass had been projected to still be within acceptable launch limits.^[80]

Each panel has a surface area of and produces 150 watts continuously when pointed towards the Sun while orbiting Jupiter.^[81] While in Europa's shadow, batteries will enable the spacecraft to continue gathering data. However, ionizing radiation can damage solar panels. The Europa Clipper orbit will pass through Jupiter's intense magnetosphere, which is expected to gradually degrade the solar panels as the mission progresses. The solar panels were provided by Airbus Defence and Space, Netherlands.^[82]

Propulsion

The propulsion subsystem was built by NASA's Goddard Space Flight Center in Greenbelt, Maryland. It is part of the Propulsion Module,^[83] delivered by Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. It is 10feet tall, 5feet in diameter and comprises about two-thirds of the spacecraft's main body. The propulsion subsystem carries nearly 6000lb of monomethyl hydrazine and dinitrogen tetroxide propellant, 50% to 60% of which will be used for the 6 to 8-hour Jupiter orbit insertion burn. The spacecraft has a total of 24 rocket engines rated at 27.5 N (6.2 lbf) thrust for attitude control and propulsion.

Communication

The probe contains multiple antennas, including the high-gain antenna, which has a 3.1-meter (10-foot) diameter. The high-gain antenna operates on X-band frequencies of 7.2 and 8.4 gigahertz, and a Ka-band frequency of 32 gigahertz (12 times that of a typical cell phone).The antennas will be used to research gravity and radio science, allowing researchers to learn more about Europa's gravity^[84] It was designed and constructed by a team led by Matt Bray at the Johns Hopkins Applied Physics Laboratory, before being tested at Langley Research Center and Goddard Space Flight Center in the spring and summer of 2022.^[85]

Scientific payload

The Europa Clipper mission is equipped with nine scientific instruments.^[86] The nine science instruments for the orbiter, announced in May 2015, have a planned total mass of .^[87]

Europa Thermal Emission Imaging System (E-THEMIS)

The Europa Thermal Emission Imaging System will provide high spatial resolution as well as multi-spectral imaging of the surface of Europa in the mid to far infrared bands to help detect geologically active sites and areas, such as potential vents erupting plumes of water into space. The principal investigator is Philip Christensen of Arizona State University. This instrument is derived from the Thermal Emission Imaging System (THEMIS) on the 2001 Mars Odyssey orbiter, also developed by Philip Christensen.^[88]

Mapping Imaging Spectrometer for Europa (MISE)

The Mapping Imaging Spectrometer for Europa is an imaging near infrared spectrometer to probe the surface composition of Europa, identifying and mapping the distributions of organics (including amino acids and tholins^{[89] [90]}), salts, acid hydrates, water ice phases, and other materials. From these measurements, scientists expect to be able to relate the moon's surface composition to the habitability of its ocean.^[91] The principal investigator is Diana Blaney of Jet Propulsion Laboratory and the instrument was built in collaboration with the Johns Hopkins University Applied Physics Laboratory (APL).

Europa Imaging System (EIS)

The Europa Imaging System is a visible spectrum imaging suite to map Europa's surface and study smaller areas in high resolution, as low as 0.5m (01.6feet) per pixel. The principal investigator is Elizabeth Turtle of the Applied Physics Laboratory. It consists of two cameras, both of which use 2048x4096 pixel CMOS detectors:^{[92] [93]}

• The Wide-angle Camera (WAC) has a field of view of 48° by 24° and a resolution of from a 50km (30miles) altitude. Optically the WAC uses 8 lens refractive optics with an 8 mm aperture and a 46 mm focal length which give it a f-number of f/5.75. The WAC will obtain stereo imagery swaths throughout the mission.
• The Narrow-angle Camera (NAC) has a 2.3° by 1.2° field of view, giving it a resolution of 0.5m (01.6feet) per pixel from a altitude. Optically the NAC uses a Ritchey Chrétien Cassegrain telescope with a 152 mm aperture and a 1000 mm focal length which give it a f-number of f/6.58. The NAC is mounted on a 2-axis gimbal, allowing it to point at specific targets regardless of the main spacecraft's orientation. This will allow for mapping of >95% of Europa's surface at a resolution of ≤50m (160feet) per pixel. For reference, only around 14% of Europa's surface has previously been mapped at a resolution of ≤500m (1,600feet) per pixel.

Europa Ultraviolet Spectrograph (Europa-UVS)

The Europa Ultraviolet Spectrograph instrument will be able to detect small plumes and will provide valuable data about the composition and dynamics of the moon's exosphere. The principal investigator is Kurt Retherford of Southwest Research Institute. Retherford was previously a member of the group that discovered plumes erupting from Europa while using the Hubble Space Telescope in the UV spectrum.^[94]

Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON)

The (REASON)^{[95] [96]} is a dual-frequency ice penetrating radar (9 and 60 MHz) instrument that is designed to characterize and sound Europa's ice crust from the near-surface to the ocean, revealing the hidden structure of Europa's ice shell and potential water pockets within. REASON will probe the exosphere, surface and near-surface and the full depth of the ice shell to the ice-ocean interface up to 30 km. The principal investigator is Donald Blankenship of the University of Texas at Austin.^[97] This instrument was built by Jet Propulsion Laboratory.

Europa Clipper Magnetometer (ECM)

The Europa Clipper Magnetometer (ECM) will be used to characterize the magnetic fields around Europa. The instrument consists of three magnetic flux gates placed along an 8 m (25 ft) boom, which were stowed during launch and deployed afterwards.^[98] By studying the strength and orientation of Europa's magnetic field over multiple flybys, scientists hope to be able to confirm the existence of Europa's subsurface ocean, as well as characterize the thickness of its icy crust and measure the water's depth and salinity. The instrument team leader is Margaret Kivelson, University of Michigan.^{[99] [100]}

ECM replaced the proposed Interior Characterization of Europa using Magnetometry (ICEMAG) instrument, which was canceled due to cost overruns.^[101] ECM is a simpler and cheaper magnetometer than ICEMAG would have been.^[102]

Plasma Instrument for Magnetic Sounding (PIMS)

The Plasma Instrument for Magnetic Sounding (PIMS) measures the plasma surrounding Europa to characterize the magnetic fields generated by plasma currents. These plasma currents mask the magnetic induction response of Europa's subsurface ocean. In conjunction with a magnetometer, it is key to determining Europa's ice shell thickness, ocean depth, and salinity. PIMS will also probe the mechanisms responsible for weathering and releasing material from Europa's surface into the atmosphere and ionosphere and understanding how Europa influences its local space environment and Jupiter's magnetosphere. The principal investigator is Joseph Westlake of the Applied Physics Laboratory.^{[103] [104]}

Mass Spectrometer for Planetary Exploration (MASPEX)

The Mass Spectrometer for Planetary Exploration (MASPEX) will determine the composition of the surface and subsurface ocean by measuring Europa's extremely tenuous atmosphere and any surface materials ejected into space. Jack Waite, who led development of MASPEX, was also Science Team Lead of the Ion and Neutral Mass Spectrometer (INMS) on the Cassini spacecraft. The principal investigator is Jim Burch of Southwest Research Institute, who was previously the leader of the Magnetospheric Multiscale Mission.^{[105] [106]}

Surface Dust Analyzer (SUDA)

The SUrface Dust Analyzer (SUDA) is a mass spectrometer that will measure the composition of small solid particles ejected from Europa, providing the opportunity to directly sample the surface and potential plumes on low-altitude flybys. The instrument is capable of identifying traces of organic and inorganic compounds in the ice of ejecta,^[107] and is sensitive enough to detect signatures of life even if the sample contains less than a single bacterial cell in a collected ice grain. The principal investigator is Sascha Kempf of the University of Colorado Boulder.^[108]

Gravity & Radio Science

Although it was designed primarily for communications, the high-gain radio antenna will be used to perform additional radio observations and investigate Europa's gravitational field, acting as a radio science subsystem. Measuring the Doppler shift in the radio signals between the spacecraft and Earth will allow the spacecraft's motion to be determined in detail. As the spacecraft performs each of its 45 Europa flybys, its trajectory will be altered by the moon's gravitational field. The Doppler data will be used to determine the higher order coefficients of that gravity field, to determine the moon's interior structure, and to examine how Europa is deformed by tidal forces.^[109] The instrument team leader is Erwan Mazarico of NASA's Goddard Space Flight Center.^[110]

Launch and trajectory

Congress had originally mandated that Europa Clipper be launched on NASA's Space Launch System (SLS) super heavy-lift launch vehicle, but NASA had requested that other vehicles be allowed to launch the spacecraft due to a foreseen lack of available SLS vehicles.^[111] The United States Congress's 2021 omnibus spending bill directed the NASA Administrator to conduct a full and open competition to select a commercial launch vehicle if the conditions to launch the probe on a SLS rocket cannot be met.^[112]

On January 25, 2021, NASA's Planetary Missions Program Office formally directed the mission team to "immediately cease efforts to maintain SLS compatibility" and move forward with a commercial launch vehicle.

On February 10, 2021, it was announced that the mission would use a 5.5-year trajectory to the Jovian system, with gravity-assist maneuvers involving Mars (March 1, 2025) and Earth (December 3, 2026). Launch was targeted for a 21-day period between October 10 and 30, 2024, giving an arrival date in April 2030, and backup launch dates were identified in 2025 and 2026.

The SLS option would have entailed a direct trajectory to Jupiter taking less than three years. One alternative to the direct trajectory was identified as using a commercial rocket, with a longer 6-year cruise time involving gravity assist maneuvers at Venus, Earth and/or Mars. Additionally, a launch on a Delta IV Heavy with a gravity assist at Venus was considered.^[113]

In July 2021 the decision was announced to launch on a Falcon Heavy rocket, in fully expendable configuration. Three reasons were given: reasonable launch cost (ca. $178 million), questionable SLS availability, and possible damage to the payload due to strong vibrations caused by the solid boosters attached to the SLS launcher.^[113] The move to Falcon Heavy saved an estimated US$2 billion in launch costs alone.^{[114] [115]} NASA was not sure an SLS would be available for the mission since the Artemis program would use SLS rockets extensively, and the SLS's use of solid rocket boosters (SRBs) generates more vibrations in the payload than a launcher that does not use SRBs. The cost to redesign Europa Clipper for the SLS vibratory environment was estimated at US$1 billion.

Europa Clipper was launched on October 14, 2024, at 12:06 p.m. EDT from Launch Pad 39A at NASA's Kennedy Space Center in Florida.^[116] Hurricane Milton caused a launch attempt for October 10 to be scrubbed,^[117] resulting in the launch being finalized for October 14.

The trajectory of Europa Clipper will include a gravity assist from Mars on March 1, 2025,^[8] allowing it to speed further away from the Sun, then down towards the Sun and back out, and gain additional kinetic energy from an Earth gravity assist on December 3, 2026.^[9] The probe will then arc (reach aphelion) beyond Jupiter's orbit on October 4, 2029^[118] before slowly falling into Jupiter's gravity well and executing its orbital insertion burn in April 2030.^[119]

, the trajectory in the Jupiter system is planned as follows. After entry into the Jupiter system, Europa Clipper will perform a flyby of Ganymede at an altitude of 500km (300miles), which will reduce the spacecraft velocity by ~400m/s. This will be followed by firing the main engine at a distance of 11 Rj (Jovian radii), to provide a further ~840m/s of delta-V, sufficient to insert the spacecraft into a 202-day orbit around Jupiter. Once the spacecraft reaches the apoapsis of that initial orbit, it will perform another engine burn to provide a ~122m/s periapsis raise maneuver (PRM).

The spacecraft's cruise and science phases will overlap with the European Space Agency's JUICE spacecraft, which was launched in April 2023 and will arrive at Jupiter in July 2031. Europa Clipper is due to arrive at Jupiter 15 months prior to JUICE, despite a launch date planned 18 months later, owing to a more powerful launch vehicle and a faster flight plan with fewer gravity assists.

Public outreach

To raise public awareness of the Europa Clipper mission, NASA undertook a "Message In A Bottle" campaign, i.e. an actual "Send Your Name to Europa" campaign on June 1, 2023, through which people around the world were invited to send their names as signatories to a poem called "In Praise of Mystery: A Poem for Europa" written by the U.S. Poet Laureate Ada Limón, for the 2.9-billion-kilometer (1.8-billion mi) voyage to Jupiter. The poem connects the two water worlds – Earth, yearning to reach out and understand what makes a world habitable, and Europa, waiting with secrets yet to be explored.

The poem is engraved on Europa Clipper inside a tantalum metal plate, about 7 by 11 inches (18 by 28 centimeters), that seals an opening into the vault. The inward-facing side of the metal plate is engraved with the poem in the poet's own handwriting. The public participants' names are etched onto a microchip attached to the plate, within an artwork of a wine bottle surrounded by the four Galilean moons. After registering their names, participants received a digital ticket with details of the mission's launch and destination. According to NASA, 2,620,861 people signed their names to Europa Clipper's Message in a Bottle, most of whom were from the United States.^[120] Other elements etched on the inwards side together with the poem and names are the Drake equation, representations of the spectral lines of atomic hydrogen and the hydroxyl radical, together known as the water hole, and a portrait of planetary scientist Ron Greeley.^[121] The outward-facing panel features art that highlights Earth's connection to Europa. Linguists collected recordings of the word "water" spoken in 103 languages, from families of languages around the world. The audio files were converted into waveforms and etched into the plate. The waveforms radiate out from a symbol representing the American Sign Language sign for "water".^[122] The research organization METI International gathered the audio files for the words for "water", and its president Douglas Vakoch designed the water hole component of the message.^{[123] [124]}

Further reading

• Cochrane . Corey J. . Murphy . Neil . Raymond . Carol A. . Biersteker . John B. . Dang . Katherine . Jia . Xianzhe . Korth . Haje . Narvaez . Pablo . Ream . Jodie B. . Weiss . Benjamin P. . Magnetic Field Modeling and Visualization of the Europa Clipper Spacecraft . Space Science Reviews . June 2023 . 219 . 4 . 34 . 10.1007/s11214-023-00974-y . 37251605 . 10220138 . 2023SSRv..219...34C . 1.
• Pappalardo . Robert T. . Buratti . Bonnie J. . Korth . Haje . Senske . David A. . Blaney . Diana L. . Blankenship . Donald D. . Burch . James L. . Christensen . Philip R. . Kempf . Sascha . Kivelson . Margaret G. . Mazarico . Erwan . Retherford . Kurt D. . Turtle . Elizabeth P. . Westlake . Joseph H. . Paczkowski . Brian G. . Ray . Trina L. . Kampmeier . Jennifer . Craft . Kate L. . Howell . Samuel M. . Klima . Rachel L. . Leonard . Erin J. . Matiella Novak . Alexandra . Phillips . Cynthia B. . Daubar . Ingrid J. . Blacksberg . Jordana . Brooks . Shawn M. . Choukroun . Mathieu N. . Cochrane . Corey J. . Diniega . Serina . Elder . Catherine M. . Ernst . Carolyn M. . Gudipati . Murthy S. . Luspay-Kuti . Adrienn . Piqueux . Sylvain . Rymer . Abigail M. . Roberts . James H. . Steinbrügge . Gregor . Cable . Morgan L. . Scully . Jennifer E. C. . Castillo-Rogez . Julie C. . Hay . Hamish C. F. C. . Persaud . Divya M. . Glein . Christopher R. . McKinnon . William B. . Moore . Jeffrey M. . Raymond . Carol A. . Schroeder . Dustin M. . Vance . Steven D. . Wyrick . Danielle Y. . Zolotov . Mikhail Y. . Hand . Kevin P. . Nimmo . Francis . McGrath . Melissa A. . Spencer . John R. . Lunine . Jonathan I. . Paty . Carol S. . Soderblom . Jason M. . Collins . Geoffrey C. . Schmidt . Britney E. . Rathbun . Julie A. . Shock . Everett L. . Becker . Tracy C. . Hayes . Alexander G. . Prockter . Louise M. . Weiss . Benjamin P. . Hibbitts . Charles A. . Moussessian . Alina . Brockwell . Timothy G. . Hsu . Hsiang-Wen . Jia . Xianzhe . Gladstone . G. Randall . McEwen . Alfred S. . Patterson . G. Wesley . McNutt . Ralph L. . Evans . Jordan P. . Larson . Timothy W. . Cangahuala . L. Alberto . Havens . Glen G. . Buffington . Brent B. . Bradley . Ben . Campagnola . Stefano . Hardman . Sean H. . Srinivasan . Jeffrey M. . Short . Kendra L. . Jedrey . Thomas C. . St. Vaughn . Joshua A. . Clark . Kevin P. . Vertesi . Janet . Niebur . Curt . Science Overview of the Europa Clipper Mission . Space Science Reviews . June 2024 . 220 . 4 . 40 . 10.1007/s11214-024-01070-5 . 2024SSRv..220...40P . en . 0038-6308 . 1. free .
• Roberts . James H. . McKinnon . William B. . Elder . Catherine M. . Tobie . Gabriel . Biersteker . John B. . Young . Duncan . Park . Ryan S. . Steinbrügge . Gregor . Nimmo . Francis . Howell . Samuel M. . Castillo-Rogez . Julie C. . Cable . Morgan L. . Abrahams . Jacob N. . Bland . Michael T. . Chivers . Chase . Cochrane . Corey J. . Dombard . Andrew J. . Ernst . Carolyn . Genova . Antonio . Gerekos . Christopher . Glein . Christopher . Harris . Camilla D. . Hay . Hamish C. F. C. . Hayne . Paul O. . Hedman . Matthew . Hussmann . Hauke . Jia . Xianzhe . Khurana . Krishan . Kiefer . Walter S. . Kirk . Randolph . Kivelson . Margaret . Lawrence . Justin . Leonard . Erin J. . Lunine . Jonathan I. . Mazarico . Erwan . McCord . Thomas B. . McEwen . Alfred . Paty . Carol . Quick . Lynnae C. . Raymond . Carol A. . Retherford . Kurt D. . Roth . Lorenz . Rymer . Abigail . Saur . Joachim . Scanlan . Kirk . Schroeder . Dustin M. . Senske . David A. . Shao . Wencheng . Soderlund . Krista . Spiers . Elizabeth . Styczinski . Marshall J. . Tortora . Paolo . Vance . Steven D. . Villarreal . Michaela N. . Weiss . Benjamin P. . Westlake . Joseph H. . Withers . Paul . Wolfenbarger . Natalie . Buratti . Bonnie . Korth . Haje . Pappalardo . Robert T. . Exploring the Interior of Europa with the Europa Clipper . Space Science Reviews . September 2023 . 219 . 6 . 46 . 10.1007/s11214-023-00990-y . 37636325 . 10457249 . 2023SSRv..219...46R . 1.

External links

• • NASA – Overview of Europa

Notes and References

1. Web site: Foust . Jeff . January 29, 2021 . NASA seeks input on Europa Clipper launch options . January 30, 2021 . SpaceNews . October 10, 2022 . https://web.archive.org/web/20221010134427/https://spacenews.com/nasa-seeks-input-on-europa-clipper-launch-options/ . live .
2. Goldstein . Barry . Kastner . Jason . March 2018 . Weigh Your Options Carefully . live . The Sextant – Europa Clipper Newsletter . Jet Propulsion Laboratory . 2 . 1 . 3 . https://web.archive.org/web/20200322181337/https://europa.nasa.gov/system/internal_resources/details/original/116_Europa-Clipper-Newsletter-External-vol2issue1_FINAL.pdf . March 22, 2020 . September 20, 2018.
3. Web site: Johns Hopkins APL Delivers Propulsion Module for NASA Mission to Europa Johns Hopkins University Applied Physics Laboratory . www.jhuapl.edu . May 11, 2024 . en.
4. https://europa.nasa.gov/mission/about/ Overview | Mission – NASA's Europa Clipper
5. https://europa.nasa.gov/mission/about/ Europa Clipper Mission.
6. News: Goldstein . Barry . Pappalardo . Robert . February 19, 2015 . Europa Clipper Update . Outer Planets Assessment Group . live . July 24, 2015 . https://web.archive.org/web/20160610230138/http://www.lpi.usra.edu/opag/feb2015/presentations/04_Clipper%20OPAG%20Feb%202015.pdf . June 10, 2016.
7. NASA Awards Launch Services Contract for the Europa Clipper Mission . July 23, 2021 . NASA . Potter . Sean . July 23, 2021 . live . https://web.archive.org/web/20210724020501/https://www.nasa.gov/press-release/nasa-awards-launch-services-contract-for-europa-clipper-mission/ . July 24, 2021.
8. Web site: Eyes on the Solar System - NASA/JPL .
9. Web site: Eyes on the Solar System - NASA/JPL .
10. All Systems Go for NASA's Mission to Jupiter Moon Europa . June 17, 2015 . NASA . May 29, 2019 . live . https://web.archive.org/web/20210311172634/http://www.nasa.gov/press-release/all-systems-go-for-nasas-mission-to-jupiter-moon-europa/ . March 11, 2021.
11. Web site: Eyes on the Solar System - NASA/JPL .
12. Web site: Thompson . Jay R. . 2022 . Instruments . live . https://web.archive.org/web/20210524211103/https://europa.nasa.gov/mission/science-instruments/ . May 24, 2021 . October 10, 2022 . Europa Clipper . NASA.
13. Web site: October 14, 2024 . NASA's Europa Clipper launches aboard SpaceX rocket, bound for Jupiter's icy ocean moon . October 14, 2024 . Los Angeles Times.
14. Web site: Foust . Jeff . February 10, 2021 . NASA to use commercial launch vehicle for Europa Clipper . live . https://wayback.archive-it.org/all/20210216064656/https://spacenews.com/nasa%2Dto%2Duse%2Dcommercial%2Dlaunch%2Dvehicle%2Dfor%2Deuropa%2Dclipper/ . February 16, 2021 . February 10, 2021 . SpaceNews.
15. News: Clark . Stuart . 'It's like finding needles in a haystack': the mission to discover if Jupiter's moons support life . March 5, 2023 . . March 7, 2023 . March 7, 2023 . https://web.archive.org/web/20230307013722/https://www.theguardian.com/science/2023/mar/05/could-jupiters-icy-moons-support-life . live .
16. Web site: King . Lucinda . Conversation . The . If life exists on Jupiter's moon Europa, scientists might soon be able to detect it . April 8, 2024 . phys.org . en . April 8, 2024 . https://web.archive.org/web/20240408032324/https://phys.org/news/2024-04-life-jupiter-moon-europa-scientists.html . live .
17. Web site: Europa Clipper - NASA Science . 2024-11-19 . science.nasa.gov . en-US.
18. Web site: April 19, 2024 . How our vision of Europa's habitability is changing . April 24, 2024 . en-US . April 24, 2024 . https://web.archive.org/web/20240424173703/https://www.sciencenews.org/article/vision-europa-habitability-jupiter-moon . live .
19. Edwards . Bradley C. . Chyba . Christopher F. . Abshire . James B. . Burns . Joseph A. . Geissler . Paul . Konopliv . Alex S. . Malin . Michael C. . Ostro . Steven J. . Rhodes . Charley . July 11, 1997 . The Europa Ocean Discovery mission . Proc. SPIE 3111, Instruments, Methods, and Missions for the Investigation of Extraterrestrial Microorganisms . 10.1117/12.278778 . Chuck . Rudiger . Xuan-Min . Shao . David E. . Smith . Steven W. . Squyres . Peter C. . Thomas . Chauncey W. . Uphoff . Gerald D. . Walberg . Charles L. . Werner . Charles F. . Yoder . Maria T. . Zuber.
20. Book: Meltzer, Michael . Mission to Jupiter: A History of the Galileo Project . NASA . 2007 . The NASA History Series . 124150579 . SP-4231 . December 4, 2020 . https://web.archive.org/web/20201128052208/https://history.nasa.gov/SP-4231/sp4231.pdf . November 28, 2020 . live.
21. News: Dreier . Casey . December 12, 2013 . Europa: No Longer a 'Should', But a 'Must' . The Planetary Society . live . December 13, 2013 . https://web.archive.org/web/20190908093842/http://www.planetary.org/blogs/casey-dreier/2013/1212-europa-no-longer-a-should-but-a-must.html . September 8, 2019.
22. Web site: Schulze-Makuch . Dirk . Irwin . Louis N. . 2001 . Alternative Energy Sources Could Support Life on Europa . https://web.archive.org/web/20060703033956/http://www.geo.utep.edu/pub/dirksm/geobiowater/pdf/EOS27March2001.pdf . July 3, 2006 . Departments of Geological and Biological Sciences . University of Texas at El Paso.
23. News: Zabarenko . Deborah . March 7, 2011 . Lean U.S. missions to Mars, Jupiter moon recommended . live . July 5, 2021 . https://web.archive.org/web/20200907012354/https://www.reuters.com/article/us-space-usa-future-idUSTRE7266XJ20110308 . September 7, 2020.
24. Web site: 2005 . Project Prometheus final report . 178 . dead . https://web.archive.org/web/20160304221142/http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/38185/1/05-3441.pdf . March 4, 2016 . January 20, 2015.
25. News: Europa Clipper passes key review. Jeff Foust. August 22, 2019. Space News. July 4, 2023. February 27, 2023. https://web.archive.org/web/20230227101309/https://spacenews.com/europa-clipper-passes-key-review/. live.
26. https://www.space.com/nasa-europa-mission-alien-life.html NASA Europa Mission Could Potentially Spot Signs of Alien Life
27. Pappalardo . Robert . Cooke . Brian . Goldstein . Barry . Prockter . Louise . Senske . Dave . Magner . Tom . July 2013 . OPAG Update . Lunar and Planetary Institute . https://web.archive.org/web/20210125054349/https://www.lpi.usra.edu/opag/jul2013/presentations/Clipper_Summary.pdf . January 25, 2021 . December 13, 2013 . The Europa Clipper . http://www.lpi.usra.edu/opag/jul2013/presentations/Clipper_Summary.pdf . live.
28. Web site: Dyches . Preston . March 9, 2017 . NASA Mission Named 'Europa Clipper' . live . https://web.archive.org/web/20201202164049/https://www.jpl.nasa.gov/news/news.php?feature=6772 . December 2, 2020 . October 28, 2017 . JPL (NASA).
29. News: March 29, 2013 . Destination: Europa . Europa SETI . dead . https://web.archive.org/web/20140823091007/http://europa.seti.org/one-small-step-for-a-mission/ . August 23, 2014.
30. News: Leone . Dan . July 22, 2013 . NASA's Europa Mission Concept Progresses on the Back Burner . SpaceNews . live . January 5, 2016 . https://archive.today/20160222162720/http://spacenews.com/36388nasas-europa-mission-concept-progresses-on-the-back-burner/ . February 22, 2016.
31. News: Wall . Mike . March 5, 2014 . NASA Eyes Ambitious Mission to Jupiter's Icy Moon Europa by 2025 . Space.com . live . April 15, 2014 . https://web.archive.org/web/20180908194715/https://www.space.com/24926-nasa-europa-mission-2015-budget.html . September 8, 2018.
32. News: Clark . Stephen . March 14, 2014 . Economics, water plumes to drive Europa mission study . Spaceflight Now . live . April 15, 2014 . https://web.archive.org/web/20140416182657/http://spaceflightnow.com/news/n1403/14europa/ . April 16, 2014.
33. News: Zezima . Katie . May 8, 2014 . House gives NASA more money to explore planets . The Washington Post . live . May 9, 2014 . https://web.archive.org/web/20150513200006/http://www.washingtonpost.com/blogs/post-politics/wp/2014/05/08/house-gives-nasa-more-money-to-explore-planets/ . May 13, 2015.
34. News: Morin . Monte . May 8, 2014 . US$17.9-billion funding plan for NASA would boost planetary science . Los Angeles Times . live . May 9, 2014 . https://web.archive.org/web/20201112025606/https://www.latimes.com/science/sciencenow/la-sci-sn-nasa-house-appropriations-committee-20140507-story.html . November 12, 2020.
35. Web site: Nola Taylor Redd . November 5, 2014 . To Europa! Mission to Jupiter's Moon Gains Support in Congress . live . https://web.archive.org/web/20201127084926/https://www.space.com/27660-jupiter-moon-europa-exploration-congress.html . November 27, 2020 . November 6, 2014 . Space.com.
36. Web site: Dreier . Casey . February 3, 2015 . It's Official: We're On the Way to Europa . live . https://web.archive.org/web/20200111202738/https://www.planetary.org/blogs/casey-dreier/2015/0202-its-official-we-are-on-the-way-to-europa-fy2016.html . January 11, 2020 . February 8, 2015 . The Planetary Society.
37. Web site: Kane . Van . February 3, 2015 . 2016 Budget: Great Policy Document and A Much Better Budget . live . https://web.archive.org/web/20201108093519/http://futureplanets.blogspot.com/2015/02/2016-budget-great-policy-document-and.html . November 8, 2020 . February 8, 2015 . Future Planetary Exploration.
38. News: Clark . Stephen . March 10, 2015 . Europa Multiple Flyby Mission concept team aims for launch in 2022 . Spaceflight Now . live . April 9, 2015 . https://web.archive.org/web/20160808162453/https://spaceflightnow.com/2015/03/10/europa-clipper-concept-team-aims-for-launch-in-2022/ . August 8, 2016.
39. Di Benedetto . Mauro . Imperia . Luigi . Durantea . Daniele . Dougherty . Michele . Iessa . Luciano . September 26–30, 2016 . Augmenting NASA Europa Clipper by a small probe: Europa Tomography Probe (ETP) mission concept . 67th International Astronautical Congress (IAC).
40. http://meetingorganizer.copernicus.org/EGU2016/EGU2016-16887.pdf Akon – A Penetrator for Europa
41. News: Clark . Stephen . April 10, 2015 . NASA invites ESA to build Europa piggyback probe . Spaceflight Now . live . April 17, 2015 . https://web.archive.org/web/20201204090151/https://spaceflightnow.com/2015/04/10/nasa-invites-esa-to-build-europa-piggyback-probe/ . December 4, 2020.
42. News: Amos . Jonathan . April 19, 2016 . European scientists set eyes on ice moon Europa . BBC News . live . April 19, 2016 . https://web.archive.org/web/20201108124630/https://www.bbc.com/news/science-environment-36079069 . November 8, 2020.
43. Blanc . Michel . Jones . Geraint H. . Prieto-Ballesteros . Olga . Sterken . Veerle J. . 2016 . The Europa initiative for ESA's cosmic vision: a potential European contribution to NASA's Europa mission . live . Geophysical Research Abstracts . 18 . EPSC2016-16378 . 2016EGUGA..1816378B . https://web.archive.org/web/20200806021822/https://meetingorganizer.copernicus.org/EGU2016/EGU2016-16378.pdf . August 6, 2020 . September 29, 2016.
44. Web site: May 16, 2017 . Joint Europa Mission: ESA and NASA together towards Jupiter icy moon . live . https://web.archive.org/web/20200731031542/https://www.researchitaly.it/en/projects/joint-europa-mission-esa-and-nasa-together-towards-jupiter-icy-moon/ . July 31, 2020 . May 29, 2019 . Research Italy.
45. http://meetingorganizer.copernicus.org/EGU2017/EGU2017-12931.pdf Joint Europa Mission (JEM): A multi-scale study of Europa to characterize its habitability and search for life
46. News: Klotz . Irene . May 26, 2015 . NASA's Europa Mission Will Look for Life's Ingredients . Gazette Herald . January 30, 2021 .
47. News: Howell . Elizabeth . June 20, 2015 . NASA's Europa Mission Approved for Next Development Stage . Space.com . live . June 20, 2015 . https://web.archive.org/web/20180813111636/https://www.space.com/29713-europa-mission-approved-for-development.html . August 13, 2018.
48. News: Kornfeld . Laurel . January 4, 2016 . Additional US$1.3 billion for NASA to fund next Mars rover, Europa mission . The Space Reporter . usurped . https://web.archive.org/web/20160118071957/https://thespacereporter.com/2016/01/additional-1-3-billion-nasa-fund-next-mars-rover-europa-mission/ . January 18, 2016.
49. News: Kane . Van . January 5, 2016 . A Lander for NASA's Europa Mission . The Planetary Society . live . January 5, 2016 . https://web.archive.org/web/20160108004658/http://www.planetary.org/blogs/guest-blogs/van-kane/20160105-nasa-europa-lander.html . January 8, 2016.
50. Web site: February 8, 2017 . NASA Receives Science Report on Europa Lander Concept . live . https://web.archive.org/web/20201112015154/https://www.nasa.gov/feature/nasa-receives-science-report-on-europa-lander-concept . November 12, 2020 . October 10, 2022 . NASA.
51. Web site: December 28, 2016 . NASA'S FY2017 Budget Request – Status at the End of the 114th Congress . live . https://web.archive.org/web/20200805084147/https://www.spacepolicyonline.com/pages/images/stories/NASA%20FY2017%20budget%20request%20Dec%2028%202016.pdf . August 5, 2020 . September 29, 2017 . spacepolicyonline.com.
52. Web site: May 27, 2015 . NASA'S FY2016 Budget Request – Overview . dead . https://web.archive.org/web/20200731045549/https://spacepolicyonline.com/pages/images/stories/NASA%20FY2016%20budget%20request%20may%2027.pdf . July 31, 2020 . May 29, 2019 . spacepolicyonline.com.
53. News: Greicius . Tony . February 21, 2017 . NASA's Europa Flyby Mission Moves into Design Phase . NASA . live . February 22, 2017 . https://web.archive.org/web/20201112040348/https://www.nasa.gov/feature/jpl/nasas-europa-flyby-mission-moves-into-design-phase/ . November 12, 2020.
54. Web site: Berger . Eric . July 12, 2024 . NASA's flagship mission to Europa has a problem: Vulnerability to radiation . July 13, 2024 . Ars Technica . en-us.
55. Web site: Harwood . William . NASA clears $5 billion Jupiter mission for launch after review of suspect transistors . CBS News . September 9, 2024 . October 22, 2024.
56. News: Brown . David W. . September 17, 2024 . A $5 Billion NASA Mission Looked Doomed. Could Engineers Save It? . subscription . The New York Times.
57. Web site: NASA clears Europa Clipper mission for Oct. 10 launch despite Jupiter radiation worries . . September 4, 2024 .
58. Web site: SpaceX, NASA stand down from Oct. 10 Europa Clipper launch due to Hurricane Milton . . October 7, 2024 .
59. News: McCartney . Gretchen . Johnson . Alana . August 19, 2019 . Mission to Jupiter's Icy Moon Confirmed . NASA . live . August 20, 2019 . https://web.archive.org/web/20201130045118/https://www.jpl.nasa.gov/news/news.php?feature=7480 . November 30, 2020.
60. News: McCartney . Gretchen . Johnson . Alana . March 3, 2022 . NASA Begins Assembly of Europa Clipper Spacecraft . NASA . live . March 10, 2022 . https://web.archive.org/web/20220311032733/https://europa.nasa.gov/news/46/nasa-begins-assembly-of-europa-clipper-spacecraft/ . March 11, 2022.
61. News: McCartney . Gretchen . Johnson . Alana . June 7, 2022 . NASA's Europa Clipper Mission Completes Main Body of the Spacecraft . NASA . live . June 24, 2022 . https://web.archive.org/web/20220618194107/https://europa.nasa.gov/news/51/nasas-europa-clipper-mission-completes-main-body-of-the-spacecraft/ . June 18, 2022.
62. News: McCartney . Gretchen . Fox . Karen . Johnson . Alana . January 30, 2024 . Poised for Science: NASA's Europa Clipper Instruments Are All Aboard . NASA . January 30, 2024 . January 31, 2024 . https://web.archive.org/web/20240131152246/https://europa.nasa.gov/news/99/poised-for-science-nasas-europa-clipper-instruments-are-all-aboard/ . live .
63. Web site: March 27, 2024 . NASA's Europa Clipper Survives and Thrives in 'Outer Space' on Earth – NASA . March 28, 2024 . en-US . March 28, 2024 . https://web.archive.org/web/20240328005026/https://www.nasa.gov/missions/europa-clipper/nasas-europa-clipper-survives-and-thrives-in-outer-space-on-earth/ . live .
64. Web site: NASA's Europa Clipper Makes Cross-Country Flight to Florida . May 25, 2024 . NASA Jet Propulsion Laboratory (JPL) . en-US . May 25, 2024 . https://web.archive.org/web/20240525014511/https://www.jpl.nasa.gov/news/nasas-europa-clipper-makes-cross-country-flight-to-florida . live .
65. Web site: Foust . Jeff . September 9, 2024 . Europa Clipper passes pre-launch review . September 11, 2024 . SpaceNews . en-US.
66. Web site: 14 OPAG June 2022 Day 2 Bob Pappalardo Jordan Evans (unlisted) . YouTube . July 19, 2022 . April 15, 2024.
67. Web site: Waldek . Stefanie . NASA's Europa Clipper may crash into Ganymede, the largest moon in the solar system, at mission's end . Space.com . June 29, 2022 . April 15, 2024 . April 11, 2024 . https://web.archive.org/web/20240411142315/https://www.space.com/europa-clipper-might-crash-into-ganymede . live .
68. Pappalardo . Robert T. . Buratti . Bonnie J. . Korth . Haje . Senske . David A. . Blaney . Diana L. . 4 . Science Overview of the Europa Clipper Mission . Space Science Reviews . Springer Science and Business Media LLC . 220 . 4 . May 23, 2024 . 0038-6308 . 10.1007/s11214-024-01070-5 . free . 40. 2024SSRv..220...40P .
69. Pappalardo . Robert T. . Vance . S. . Bagenal . F. . Bills . B.G. . Blaney . D.L.. Diana Blaney . Blankenship . D.D. . Brinckerhoff . W.B. . Connerney . J.E.P. . Hand . K.P. . Hoehler . T.M. . Leisner . J.S. . Kurth . W.S. . McGrath . M.A. . Mellon . M.T. . Moore . J.M. . 2013 . Science Potential from a Europa Lander . live . Astrobiology . 13 . 8 . 740–773 . 2013AsBio..13..740P . 10.1089/ast.2013.1003 . 23924246 . https://web.archive.org/web/20221010134353/https://dspace.mit.edu/bitstream/handle/1721.1/81431/Pappalardo_Science-potential.pdf;jsessionid=FC7BE20FBB7C0C9AA9F45BDF32F8E03D?sequence=2 . October 10, 2022 . October 1, 2019 . free . Patterson . G.W. . Prockter . L.M. . Senske . D.A. . Schmidt . B.E. . Shock . E.L. . Smith . D.E. . Soderlund . K.M. . 1721.1/81431 . 10522270.
70. Bayer . Todd . Buffington . Brent . Castet . Jean-Francois . Jackson . Maddalena . Lee . Gene . Lewis . Kari . Kastner . Jason . Schimmels . Kathy . Kirby . Karen . March 4, 2017 . 2017 IEEE Aerospace Conference . 2017 IEEE Aerospace Conference . Big Sky, Montana . 1–12 . 10.1109/AERO.2017.7943832 . 978-1-5090-1613-6 . Europa mission update: Beyond payload selection.
71. News: Kane . Van . August 26, 2014 . Europa: How Less Can Be More . Planetary Society . live . August 29, 2014 . https://web.archive.org/web/20191117080735/https://www.planetary.org/blogs/guest-blogs/van-kane/20140826-europa-how-less-can-be-more.html . November 17, 2019.
72. Phillips . Cynthia B. . Cynthia B. Phillips . Pappalardo . Robert T. . May 20, 2014 . Europa Clipper Mission Concept . Eos Transactions . Eos Transactions American Geophysical Union . 95 . 20 . 165–167 . 2014EOSTr..95..165P . 10.1002/2014EO200002 . free.
73. Web site: Europa Clipper . live . https://web.archive.org/web/20210323162742/https://www.jpl.nasa.gov/missions/europa-clipper . March 23, 2021 . January 2, 2019 . NASA (JPL).
74. News: Kane . Van . May 26, 2013 . Europa Clipper Update . Future Planetary Exploration . live . December 13, 2013 . https://web.archive.org/web/20210204070619/http://futureplanets.blogspot.com/2013/05/europa-clipper-update.html . February 4, 2021.
75. Web site: Meet Europa Clipper . November 11, 2022 . NASA . November 13, 2022 . https://web.archive.org/web/20221113172234/https://europa.nasa.gov/spacecraft/meet-europa-clipper/ . live .
76. Web site: Wolfe . Alexis . McDonald . Lisa . July 21, 2017 . Balance of NASA Planetary Science Missions Explored at Hearing . live . https://web.archive.org/web/20200731023935/https://www.aip.org/fyi/2017/balance-nasa-planetary-science-missions-explored-hearing . July 31, 2020 . May 29, 2019 . American Institute of Physics.
77. Web site: Solar System Exploration Missions List . dead . https://archive.today/20180327141053/https://planetarymissions.nasa.gov/missions/solar%20system%20exploration . March 27, 2018 . March 27, 2018 . Planetary Missions Program Office (PMPO) . NASA.
78. Amato . Michael J. . Spidaliere . P. . Mahaffy . P. . 2016 . Biosignature Explorer for Europa (BEE) Probe – The Concept for Directly Searching for Life Evidence on Europa at Lower Cost and Risk . 47th Lunar and Planetary Science Conference . https://web.archive.org/web/20170122232905/http://www.hou.usra.edu/meetings/lpsc2016/pdf/2602.pdf . January 22, 2017 . September 28, 2016 . live.
79. A. Eremenko et al., "Europa Clipper spacecraft configuration evolution", 2014 IEEE Aerospace Conference, pp. 1–13, Big Sky, MT, March 1–8, 2014
80. Web site: Foust . Jeff . October 8, 2014 . Europa Clipper Opts for Solar Power over Nuclear . live . https://archive.today/20150209194443/http://spacenews.com/42121europa-clipper-opts-for-solar-power-over-nuclear/ . February 9, 2015 . February 8, 2015 . SpaceNews.
81. News: Dreier . Casey . September 5, 2013 . NASA's Europa Mission Concept Rejects ASRGs – May Use Solar Panels at Jupiter Instead . The Planetary Society . live . December 13, 2013 . https://web.archive.org/web/20180710011405/http://www.planetary.org/blogs/casey-dreier/2013/20130905-no-asrgs-for-europa.html . July 10, 2018.
82. March 2018 . Spacecraft Highlights . live . The Sextant – Europa Clipper Newsletter . Jet Propulsion Laboratory . 2 . 1 . 3 . https://web.archive.org/web/20221010134354/https://europa.nasa.gov/system/internal_resources/details/original/116_Europa-Clipper-Newsletter-External-vol2issue1_FINAL.pdf . October 10, 2022 . September 20, 2018.
83. Rehm. Jeremy. 7 July 2022 . Johns Hopkins APL Delivers Propulsion Module for NASA Mission to Europa .
84. https://europa.nasa.gov/spacecraft/meet-europa-clipper/
85. Web site: Europa Clipper High-Gain Antenna Undergoes Precision Testing at NASA Langley . NASA . August 4, 2022 . October 22, 2024.
86. Becker . T. M. . Zolotov . M. Y. . Gudipati . M. S. . Soderblom . J. M. . McGrath . M. A. . Henderson . B. L. . Hedman . M. M. . Choukroun . M. . Clark . R. N. . Chivers . C. . Wolfenbarger . N. S. . Glein . C. R. . Castillo-Rogez . J. C. . Mousis . O. . Scanlan . K. M. . Diniega . S. . Seelos . F. P. . Goode . W. . Postberg . F. . Grima . C. . Hsu . H.-W. . Roth . L. . Trumbo . S. K. . Miller . K. E. . Chan . K. . Paranicas . C. . Brooks . S. M. . Soderlund . K. M. . McKinnon . W. B. . Hibbitts . C. A. . Smith . H. T. . Molyneux . P. M. . Gladstone . G. R. . Cable . M. L. . Ulibarri . Z. E. . Teolis . B. D. . Horanyi . M. . Jia . X. . Leonard . E. J. . Hand . K. P. . Vance . S. D. . Howell . S. M. . Quick . L. C. . Mishra . I. . Rymer . A. M. . Briois . C. . Blaney . D. L. . Raut . U. . Waite . J. H. . Retherford . K. D. . Shock . E. . Withers . P. . Westlake . J. H. . Jun . I. . Mandt . K. E. . Buratti . B. J. . Korth . H. . Pappalardo . R. T. . August 2024 . Exploring the Composition of Europa with the Upcoming Europa Clipper Mission . Space Science Reviews . 220 . 5 . 49 . 2024SSRv..220...49B . 10.1007/s11214-024-01069-y . 1572-9672 . 15 . en. free .
87. News: May 26, 2015 . NASA's Europa Mission Begins with Selection of Science Instruments . NASA (JPL) . live . May 27, 2015 . https://web.archive.org/web/20200926192203/https://www.jpl.nasa.gov/news/news.php?feature=4598 . September 26, 2020.
88. Web site: April 25, 2019 . E-THEMIS Christensen Research Group . live . https://web.archive.org/web/20221010134358/https://christensen.asu.edu/instrument/e-themis/ . October 10, 2022 . May 14, 2021 . Christensen Research Group . Arizona State University.
89. http://adsabs.harvard.edu/abs/2017AAS...22913804W MISE: A Search for Organics on Europa
90. News: May 27, 2015 . Europa Mission to Probe Magnetic Field and Chemistry . Jet Propulsion Laboratory . live . October 23, 2017 . https://web.archive.org/web/20201202163713/https://www.jpl.nasa.gov/news/news.php?feature=4602 . December 2, 2020.
91. News: Blaney . Diana L.. Diana Blaney . 2010 . Europa Composition Using Visible to Short Wavelength Infrared Spectroscopy . JPL . American Astronomical Society, DPS meeting No. 42, #26.04; Bulletin of the American Astronomical Society, Vol. 42, p. 1025.
92. Web site: Turtle . Elizabeth . Elizabeth Turtle . Mcewen . Alfred . Alfred McEwen . Collins . G. . Fletcher . L. . Hansen . C. . Hayes . A. . Hurford . T. . Kirk . R. . Mlinar . A.C. . THE EUROPA IMAGING SYSTEM (EIS): HIGH RESOLUTION IMAGING AND TOPOGRAPHY TO INVESTIGATE EUROPA'S GEOLOGY, ICE SHELL, AND POTENTIAL FOR CURRENT ACTIVITY. . live . https://web.archive.org/web/20210305231100/https://www.hou.usra.edu/meetings/lpsc2016/pdf/1626.pdf . March 5, 2021 . May 14, 2021 . Universities Space Research Association.
93. Web site: Europa Clipper Instrument Summaries .
94. Roth . Lorenz . 2014 . Transient Water Vapor at Europa's South Pole . . 343 . 171 . 171–174 . 2014Sci...343..171R . 10.1126/science.1247051 . 1095-9203 . 24336567 . 27428538.
95. News: June 1, 2015 . Radar Techniques Used in Antarctica Will Scour Europa for Life-Supporting Environments . University of Texas Austin . live . June 4, 2015 . https://archive.today/20151115171717/http://astrobiology.com/2015/06/radar-techniques-used-in-antarctica-will-scour-europa-for-life-supporting-environments.html . November 15, 2015.
96. Grima . Cyril . Schroeder . Dustin . Blakenship . Donald D. . Young . Duncan A. . November 15, 2014 . Planetary landing-zone reconnaissance using ice-penetrating radar data: Concept validation in Antarctica . Planetary and Space Science . 103 . 191–204 . 2014P&SS..103..191G . 10.1016/j.pss.2014.07.018 . free.
97. Blankenship . Donald D. . Moussessian . Alina . Chapin . Elaine . Young . Duncan A. . Patterson . G. . Plaut . Jeffrey J. . Freedman . Adam P. . Schroeder . Dustin M. . Grima . Cyril . Steinbrügge . Gregor . Soderlund . Krista M. . Ray . Trina . Richter . Thomas G. . Jones-Wilson . Laura . Wolfenbarger . Natalie S. . June 2024 . Radar for Europa Assessment and Sounding: Ocean to Near-Surface (REASON) . . en . 220 . 5 . 51 . 10.1007/s11214-024-01072-3 . 1572-9672 . 11211191 . 38948073. 2024SSRv..220...51B .
98. Web site: ECM Instruments – NASA's Europa Clipper . October 11, 2022 . NASA . October 4, 2022 . https://web.archive.org/web/20221004131828/https://europa.nasa.gov/spacecraft/instruments/ecm/ . live .
99. Kivelson . Margaret G. . Jia . Xianzhe . Lee . Karen A. . Raymond . Carol A. . Khurana . Krishan K. . Perley . Mitchell O. . Biersteker . John B. . Blacksberg . Jordana . Caron . Ryan . Cochrane . Corey J. . Dawson . Olivia R. . Harris . Camilla D. K. . Jones . Jonathan E. . Joy . Steven . Korth . Haje . Liu . Jiang . Maghsoudi . Elham . Murphy . Neil . Parsley . David . Pierce . David R. . Racho . Caroline . Richter . Ingo . Russell . Christopher T. . Sherman . Sarah . Strangeway . Robert J. . Villarreal . Mickey . Weiss . Benjamin P. . Wigglesworth . Lee . The Europa Clipper Magnetometer . Space Science Reviews . September 2023 . 219 . 6 . 48 . 10.1007/s11214-023-00989-5 . 2023SSRv..219...48K . 1. free .
100. Web site: ECM: How We'll Use It . October 11, 2022 . NASA . October 4, 2022 . https://web.archive.org/web/20221004131828/https://europa.nasa.gov/spacecraft/instruments/ecm/#otp_how_we'll_use_it . live .
101. Web site: Foust . Jeff . March 6, 2019 . NASA to replace Europa Clipper instrument . April 26, 2019 . SpaceNews . October 10, 2022 . https://web.archive.org/web/20221010134356/https://spacenews.com/nasa-to-replace-europa-clipper-instrument/ . live .
102. Web site: March 5, 2019 . NASA Seeks New Options for Science Instrument on Europa Clipper . live . https://web.archive.org/web/20210219064432/https://www.nasa.gov/feature/jpl/nasa-seeks-new-options-for-science-instrument-on-europa-clipper/ . February 19, 2021 . March 13, 2019 . NASA.
103. Westlake . Joseph . Rymer . A. M. . Kasper . J. C. . McNutt . R. L. . Smith . H. T. . Stevens . M. L. . Parker . C. . Case . A. W. . Ho . G. C. . 2014 . The Influence of Magnetospheric Plasma on Magnetic Sounding of Europa's Interior Oceans . Workshop on the Habitability of Icy Worlds (2014) . https://web.archive.org/web/20160610204847/http://www.hou.usra.edu/meetings/icyworlds2014/pdf/4032.pdf . June 10, 2016 . May 27, 2015 . Mitchell . D. G. . live.
104. Joseph . Westlake . December 14, 2015 . The Plasma Instrument for Magnetic Sounding (PIMS): Enabling Required Plasma Measurements for the Exploration of Europa . live . AGU Fall Meeting Abstracts . AGU . 2015 . 13E–09 . 2015AGUFM.P13E..09W . https://web.archive.org/web/20170123035543/https://agu.confex.com/agu/fm15/webprogram/Paper66117.html . January 23, 2017 . June 21, 2016.
105. Web site: Mass Spectrometer for Planetary Exploration / Europa (MASPEX) . live . https://web.archive.org/web/20210519011818/https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=EUROPA-CL-08 . May 19, 2021 . May 18, 2021 . . NASA.
106. Web site: Waite . Jack . Lewis . W. . Kasprzak . W. . Anicich . V. . Block . B. . Cravens . T. . Fletcher . G. . Ip . W. . Luhmann . J . August 13, 1998 . THE CASSINI ION AND NEUTRAL MASS SPECTROMETER (INMS) INVESTIGATION . live . https://web.archive.org/web/20211228164227/https://www.lpl.arizona.edu/~yelle/eprints/Waite04a.pdf . December 28, 2021 . May 18, 2021 . . University of Arizona.
107. Kempf . Sascha . etal . May 2012 . Linear high resolution dust mass spectrometer for a mission to the Galilean satellites . Planetary and Space Science . 65 . 1 . 10–20 . 2012P&SS...65...10K . 10.1016/j.pss.2011.12.019.
108. 10.1126/sciadv.adl0849 . How to identify cell material in a single ice grain emitted from Enceladus or Europa . 2024 . Klenner . Fabian . Bönigk . Janine . Napoleoni . Maryse . Hillier . Jon . Khawaja . Nozair . Olsson-Francis . Karen . Cable . Morgan L. . Malaska . Michael J. . Kempf . Sascha . Abel . Bernd . Postberg . Frank . Science Advances . 10 . 12 . eadl0849 . 38517965 . 10959401 . 2024SciA...10L.849K .
109. Mazarico . Erwan . Buccino . Dustin . Castillo-Rogez . Julie . Dombard . Andrew J. . Genova . Antonio . Hussmann . Hauke . Kiefer . Walter S. . Lunine . Jonathan I. . McKinnon . William B. . Nimmo . Francis . Park . Ryan S. . Roberts . James H. . Srinivasan . Dipak K. . Steinbrügge . Gregor . Tortora . Paolo . Withers . Paul . The Europa Clipper Gravity and Radio Science Investigation . Space Science Reviews . June 2023 . 219 . 4 . 30 . 10.1007/s11214-023-00972-0 . 2023SSRv..219...30M . 1. free .
110. Web site: Gravity/Radio Science Instruments . November 12, 2022 . NASA . November 12, 2022 . https://web.archive.org/web/20221112081205/https://europa.nasa.gov/spacecraft/instruments/gravity-radio-science/ . live .
111. Web site: Foust . Jeff . July 10, 2020 . Cost growth prompts changes to Europa Clipper instruments . July 10, 2020 . SpaceNews . September 29, 2021 . https://web.archive.org/web/20210929074855/https://spacenews.com/cost-growth-prompts-changes-to-europa-clipper-instruments/ . live .
112. News: Howell . Elizabeth . December 22, 2020 . NASA receives US$23.3 billion for 2021 fiscal year in Congress' omnibus spending bill . SPACE.com . live . December 29, 2020 . https://web.archive.org/web/20210116062645/https://www.space.com/nasa-2021-budget-congress-omnibus-spending-bill . January 16, 2021.
113. Web site: Berger . Eric . Eric Berger (meteorologist) . July 23, 2021 . SpaceX to launch the Europa Clipper mission for a bargain price . live . https://web.archive.org/web/20210805032226/https://arstechnica.com/science/2021/07/spacex-to-launch-the-europa-clipper-mission-for-a-bargain-price/ . August 5, 2021 . October 10, 2022 . Ars Technica.
114. Web site: Ralph . Eric . SpaceX Falcon Heavy to launch NASA ocean moon explorer, saving the US billions . live . https://web.archive.org/web/20211128000524/https://www.teslarati.com/spacex-falcon-heavy-nasa-ocean-moon-mission/ . November 28, 2021 . November 28, 2021 . Teslarati. July 25, 2021 .
115. Web site: Berger . Eric . July 23, 2021 . SpaceX to launch the Europa Clipper mission for a bargain price . live . https://web.archive.org/web/20210805032226/https://arstechnica.com/science/2021/07/spacex-to-launch-the-europa-clipper-mission-for-a-bargain-price/ . August 5, 2021 . November 28, 2021 . arstechnica.
116. Web site: SpaceX Falcon Heavy rocket launches NASA's Europa Clipper probe to explore icy Jupiter ocean moon . . October 14, 2024 .
117. Web site: Harwood . William . October 6, 2024 . FAA clears European asteroid probe for launch, but stormy weather threatens delay . October 7, 2024 . CBS News . en-US.
118. Web site: Eyes on the Solar System: October 4, 2029 . NASA. November 7, 2024 . November 7, 2024. See also the point at which deldot equals 0 for Clipper relative to the Sun in the Horizons system app.
119. Manley, Scott. SpaceX Ditched an Entire Falcon Heavy To Launch NASA's Massive Probe To Europa! . YouTube. Scott Manley . 3 minutes 40 seconds. YouTube video . October 21, 2024 . October 25, 2024.
120. Web site: NASA's Message in a Bottle . March 24, 2024 . NASA's Europa Clipper . en . June 16, 2024 . https://web.archive.org/web/20240616100628/https://europa.nasa.gov/message-in-a-bottle/join-us/?utm_source=message_in_a_bottle_share&utm_medium=organic&utm_campaign=message_in_a_bottle&utm_content=europa_clipper . live .
121. Web site: NASA Unveils Design for Message Heading to Jupiter's Moon Europa . NASA Jet Propulsion Laboratory (JPL) . March 11, 2024 . March 9, 2024 . https://web.archive.org/web/20240309115210/https://www.jpl.nasa.gov/news/nasa-unveils-design-for-message-heading-to-jupiters-moon-europa . live .
122. Web site: An Astrobiology Droid Asks And Answers 'How Many Ways Can You Say Water'?. Keith. Cowing. March 9, 2024. Astrobiology. March 11, 2024. June 16, 2024. https://web.archive.org/web/20240616100627/https://astrobiology.com/2024/03/an-astrobiology-droid-asks-and-answers-how-many-ways-can-you-say-water.html. live.
123. Web site: Vakoch . Douglas . Douglas Vakoch . March 27, 2024 . See the messages NASA is sending to Jupiter's icy moon, Europa . . May 28, 2024 . May 28, 2024 . https://web.archive.org/web/20240528014421/https://www.newscientist.com/article/mg26134840-200-see-the-messages-nasa-is-sending-to-jupiters-icy-moon-europa/ . live .
124. Web site: Vakoch . Douglas . Douglas Vakoch . March 28, 2024 . NASA's mission to an ice-covered moon will contain a message between water worlds . . May 28, 2024 . June 16, 2024 . https://web.archive.org/web/20240616100948/https://theconversation.com/nasas-mission-to-an-ice-covered-moon-will-contain-a-message-between-water-worlds-225771 . live .