NASA and SpaceX have launched NASA’s Europa Clipper mission to Jupiter’s icy moon Europa atop a SpaceX Falcon Heavy rocket. Falcon Heavy launched during an instantaneous launch window on Monday, Oct. 14, at 12:05 PM EDT (16:05 UTC) from Launch Complex 39A (LC-39A) at the Kennedy Space Center in Cape Canaveral, Florida. If Monday’s attempt was scrubbed, a backup launch opportunity was available for Tuesday, Oct. 15, as well as throughout the rest of October, but these attempts were not needed.
Europa Clipper is perhaps the most important planetary science mission launching this decade. One of NASA’s large strategic science missions (also known as a flagship mission), Europa Clipper will be the largest planetary science mission ever developed by NASA and the first mission to perform an in-depth investigation of Europa and its potential habitability.
Europa Clipper’s history
Planetary scientists and space agencies alike have long desired and planned a mission to Europa. Scientists first found indications of water ice on Europa in the 1950s, and subsequent missions to Jupiter, such as Galileo, Cassini-Huygens, and Juno, have revealed more about the planet’s watery nature. This culminated in the discovery of a subsurface ocean beneath the moon’s icy surface.
However, while scientists have substantial evidence for the existence of a subsurface ocean, most notably through the presence of surface water vapor plumes, the existence of the ocean has not been explicitly confirmed. Given Europa’s location in the solar system and the likelihood of a subsurface ocean containing elements that allow for the existence of life, the need for a mission to Europa increased substantially throughout the 2000s and 2010s.
A Europa orbiter mission was first proposed to NASA in 1997 for the agency’s Discovery program. Though this mission was ultimately not selected, NASA’s Jet Propulsion Laboratory (JPL) later announced that the agency would conduct an orbiter mission to Europa in the future.
Around the time of this first mission proposal, NASA’s Galileo mission was in orbit around Jupiter and regularly made flybys of the moon during its main mission and its extended mission, which was known as the Galileo Europa Mission (GEM). Galileo’s extensive investigations of Europa and Jupiter’s other icy moons allowed scientists to make many discoveries regarding icy moons and Europa, especially regarding the moon’s potential for harboring microbial extraterrestrial life. Following Galileo’s mission, NASA and JPL began conducting preliminary studies into missions to Europa.
Several proposed missions emerged from these preliminary studies. The first was the Jupiter Icy Moons Orbiter (JIMO) mission, which was planned for launch in 2015 and expected to explore Europa and Jupiter’s other icy moons, Callisto and Ganymede. JIMO was ultimately canceled in 2005 as NASA shifted its priorities to crewed space missions, and it lost funding. Following JIMO, NASA joined the European Space Agency (ESA) in formulating the Europa Jupiter System Mission – Laplace (EJSM-Laplace) mission, which was also ultimately canceled in 2011 due to budgeting issues on NASA’s side. ESA would continue the development of the EJSM-Laplace mission without NASA, eventually culminating in the agency’s Jupiter Icy Moons Explorer (JUICE) mission, which launched in April 2023.
Though EJSM-Laplace’ was canceled and ESA moved forward with its development of a Europa mission, NASA still had plans for a Europa orbiter and would use its infrastructure from EJSM-Laplace to create the Jupiter Europa Orbiter (JEO). JEO was originally scheduled for launch in 2020 and would have explored both Europa and Io. During the development of JEO, however, NASA’s budget again forced changes, and the mission was re-formulated into the Europa Multiple Flyby Mission, which was later renamed to Europa Clipper.

Juno image of Europa in September 2022. (Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill)
The desire for Europa Clipper was further bolstered when the National Research Council recommended a mission to Europa in 2013. It was decided that the mission would be a joint mission between Johns Hopkins University’s Applied Physics Laboratory (APL) and JPL.
In March 2013, the mission was granted $75 million to assist with the formation of mission teams, activities, mission goals, and instrument development (which was recommended by the 2011 Planetary Science Decadal Survey). The mission’s funding was significantly increased in May 2014, when a House bill increased the mission’s funding budget for the 2014 fiscal year from $15 million to $100 million, which was also to be used for mission formulation needs. What’s more, a further $30 million was granted to the mission for use in preliminary studies, and additional bipartisan support for the mission was promised following the 2014 United States election.
NASA selected the nine instruments that would fly with Europa Clipper in May 2015. The instruments were budgeted at approximately $110 million over the following three years. NASA formally approved the concept for Europa Clipper in June 2015, officially moving the mission to the formulation stage. In February 2017, Europa Clipper moved from Phase A to Phase B, also known as the preliminary design phase. The House Space Subcommittee held hearings in July 2017 regarding scheduling Europa Clipper as one of NASA’s large strategic science missions, which was approved. Phase B would continue until August 2019, when the mission moved to Phase C — final design and fabrication.
From 2019 to 2022, the mission’s design was finalized and the first components of the spacecraft began to be constructed. In March 2022, Europa Clipper moved to Phase D, assembly, testing, and launch, and the spacecraft’s main body was completed on June 7, 2022. On Jan. 30, 2024, all nine of Europa Clipper’s science instruments were integrated into the spacecraft, with some antennas and solar arrays being added to the spacecraft a few months later.

Europa Clipper being encapsulated within Falcon Heavy’s payload fairings on Oct. 2. (Credit: NASA/Ben Smegelsky)
By March 2024, the spacecraft successfully completed all of its main testing objectives and was prepared for its shipment to the Kennedy Space Center. In May 2024, the spacecraft arrived in Florida, and the mission’s final pre-launch review was completed in September 2024.
Europa Clipper was initially scheduled to launch at the opening of its launch window on Oct. 10, 2024. However, due to Hurricane Milton’s approach and ultimate landfall on Florida’s west coast, the launch of the mission was delayed indefinitely until the storm safely passed through the Kennedy Space Center and the center was declared safe from any substantial damage. The center was reopened over the weekend of Oct. 11, and a new launch date — Oct. 14 — was announced. During the storm, the spacecraft was safely stored in a secure location.
The Europa Clipper spacecraft and mission
The Europa Clipper mission, now valued at $2 billion, is designed to investigate Europa’s interior and ocean, geology, chemistry, and potential habitability. As mentioned, the spacecraft carries a suite of nine science instruments that will enable the mission’s investigations. Europa Clipper’s instruments can be divided into four main groups: imagers, plasma and magnetic field instruments, radar and gravity instruments, and chemical analysis instruments.

Diagram of the Europa Clipper spacecraft and its instruments. (Credit: Caltech)
Europa Clipper’s two main imagers are the Europa Imaging System (EIS) and Europa Thermal Emission Imaging System (E-THEMIS). The EIS features a wide-angle camera and a narrow-angle camera, both of which have eight-megapixel sensors that will produce high-resolution color and stereoscopic imagery of Europa’s geologic activity, surface elevations, and more. E-THEMIS will use infrared light to determine where warm liquid water may be located on Europa’s surface, which could indicate places where water plumes once erupted. E-THEMIS will also determine the small-scale properties of Europa’s surface by performing in-depth observations of Europa’s surface texture.
Two instruments will be onboard Europa Clipper to perform spectrometry at Europa. The Europa Ultraviolet Spectrograph (Europa-UVS) instrument features a telescope that collects UV light and creates images that the spacecraft’s spectrograph uses to determine the composition of Europa’s atmospheric gases and surface materials and search for plume activity around Europa. The Mapping Imaging Spectrometer for Europa (MISE) instrument is an infrared spectrometer that is expected to map the distribution of ice, salt, organics, hotspots, and more around Europa’s surface, which will allow scientists to determine Europa’s geologic history and habitability.
The Europa Clipper Magnetometer (ECM) and Plasma Instrument for Magnetic Sounding (PIMS) instruments will perform plasma and magnetic field measurements for the mission. The ECM is a magnetometer that will investigate the existence, depth, and salinity of Europa’s subsurface ocean and measure the thickness and characteristics of the moon’s icy surface shell. The ECM will also study the moon’s thin ionized atmosphere and how it interacts with Jupiter’s ionized atmosphere. PIMS and its Faraday cups will distinguish the distortions of magnetic fields near Europa that are caused by the moon’s ionosphere and plasma trapped within Jupiter’s magnetosphere. Interestingly, these distortions could carry information regarding Europa’s ocean.
Through radar and gravity measurements, details regarding Europa’s interior and other properties can be revealed. Europa Clipper will perform a variety of gravity and radar measurements using its suite of antennas and the Doppler effect. Additionally, the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) instrument, an ice-penetrating radar, will investigate the structure and thickness of Europa’s icy shell, as well as the moon’s surface elevations, composition, roughness, and atmosphere.
The remaining suite of instruments will perform chemical analysis experiments at Europa. The Mass Spectrometer for Planetary Exploration/Europa (MASPEX) instrument is a mass spectrometer that will analyze Europa’s atmosphere for different gases and potential plumes, the chemistry of the subsurface ocean, how ocean and surface exchange materials, and how radiation can alter different compounds on the moon’s icy surface. The Surface Dust Analyzer (SUDA) will identify and analyze surface material ejected from Europa’s surface via meteorite impacts. This “dust” could offer clues to scientists about the salinity of the moon’s subsurface ocean.
These nine instruments will allow Europa Clipper to achieve its daring mission goals, which, according to NASA, are to “determine the thickness of Europa’s icy shell and how the ocean interacts with the surface,” “investigate Europa’s composition, and “characterize the geology of Europa.” These nine instruments, as well as other vital electronic components, will be protected from the intense radiation surrounding Jupiter by a 150 kg titanium and aluminum shield. In total, all nine instruments mass around 82 kg.
In October 2014, it was announced that Europa Clipper would use solar panels as its main source of power when at Europa. This decision came after long discussions regarding the spacecraft’s power source. In addition to photovoltaic power sources (solar panels), radioisotope thermoelectric generator (RTG) power sources were also considered. NASA’s Juno mission proved that solar panels are a viable source of power for missions to Jupiter, and when coupled with the fact that solar panels are significantly cheaper and less complex than RTGs, solar panels were ultimately the preferred choice for Europa Clipper’s power. Additionally, though solar panels weigh more than an RTG, Europa Clipper’s projected mass was still within the set limits.
Europa Clipper will have two sets of solar panels. Each array will span 14.2 m in length and 4.1 m in height. When fully deployed following launch, Europa Clipper’s total length will increase to more than 30.5 m or roughly the size of a basketball court.
The spacecraft’s propulsion system will measure three meters in height and 1.5 m in diameter, comprising around two-thirds of the spacecraft’s main body. Built by NASA’s Goddard Space Flight Center in Maryland and owned by Johns Hopkins’ APL, the propulsion system will carry around 2,700 kg of propellant, which will be monomethyl hydrazine and dinitrogen tetroxide, of which 50 to 60 percent will be used for the spacecraft’s insertion burn around Jupiter, which will last around six to eight hours. In total, the propulsion system features 24 engines, rated at 27.5 N of thrust.
Given Europa’s location within Jupiter’s harsh radiation belts, the environment surrounding Europa is incredibly harsh, meaning that even a well-shielded spacecraft sent to orbit the moon would realistically only survive for just a few months. Because of this, Europa Clipper’s mission planners opted for more mission time and will, instead, have the spacecraft perform nearly 50 close flybys of the Moon, during which the spacecraft will collect data. Following the flybys, the spacecraft will have around seven to 10 days to transmit data to Earth. While this approach seems to limit the total amount of data that can be collected and transmitted by the spacecraft, this approach will actually allow the mission to produce almost three times as much data as an orbiter while also reducing the spacecraft’s exposure to radiation and preserving its overall health.
During its 3.5-year-long mission, the spacecraft will use its flybys of Europa, Callisto, and Ganymede to alter its orbit around Jupiter, which, in turn, alters the spacecraft’s flyby trajectories around Europa. This means that none of the spacecraft’s flybys will be the same, and will ultimately allow Europa Clipper to map out nearly the entirety of Europa’s surface. What’s more, each flyby will vary greatly in altitude, with some flybys coming within 50 km of Europa’s surface while others will be as far as 2,500 km from the surface.

Europa Clipper’s trajectory to Jupiter following launch. (Credit: NASA/JPL-Caltech)
However, before Europa Clipper arrives at Jupiter and begins performing groundbreaking science, the spacecraft must travel through the solar system for several years. In total, Europa Clipper’s journey to Jupiter will take 5.5 years and span 2.9 billion km, during which the spacecraft will perform two gravity-assist flybys of Mars and Earth in February 2025 and December 2026, respectively. Each gravity assist will allow Europa Clipper to alter its trajectory around the Sun, with the final Earth flyby and subsequent small course correction maneuvers bringing the spacecraft’s trajectory in line with Jupiter. Europa Clipper is scheduled to arrive at the planet in April 2030, after which it will perform an insertion burn to insert itself within Jupiter’s sphere of influence.
Europa Clipper’s launch
Europa Clipper was launched atop a SpaceX Falcon Heavy rocket from LC-39A in Florida. However, Europa Clipper was not initially expected to fly atop Falcon Heavy and instead was planned to launch on NASA’s Space Launch System (SLS) super-heavy lift rocket after the U.S. Congress mandated the spacecraft use the rocket for launch.
In 2021, NASA requested that other launch vehicles be allowed to launch the spacecraft after the agency predicted that it would be unable to provide an SLS launch vehicle in time for the spacecraft’s projected 2024 launch window. Thus, Congress’ 2021 omnibus spending bill directed a full and open investigation to select a commercial launch vehicle for Europa Clipper should SLS not be ready for the spacecraft’s launch in 2024. In January 2021, Europa Clipper’s mission team was directed by NASA’s Planetary Missions Program Office to “immediately cease efforts to maintain SLS compatibility.”

Artist’s impression of SLS launching Europa Clipper. (Credit: Nathan Koga for NSF)
In July 2021, NASA announced that SpaceX’s Falcon Heavy had been selected to launch Europa Clipper, citing launch costs, SLS availability, and shaking/vibrations during launch as their main motives for selecting Falcon Heavy. Though moving from SLS to Falcon Heavy meant adding more than 2.5 years to the mission’s overall timeline and coast phase, the move also allowed teams to save around $2 billion in launch costs alone. What’s more, the cost of redesigning Europa Clipper for the immense vibratory environment created by SLS’s solid rocket boosters would have cost around $1 billion.
Thus, Falcon Heavy was selected as the launch vehicle for Europa Clipper, and following the spacecraft’s arrival in Florida and final testing, Europa Clipper was integrated to its Falcon Heavy rocket in early October. On Oct. 13, NASA and SpaceX completed their Launch Readiness Review (LRR) and polled “go” for launch.
The launch of Europa Clipper was Falcon Heavy’s 11th mission of all time and second of 2024. For SpaceX, the launch was the company’s 396th total launch and 96th of 2024, and the 185th orbital launch attempt worldwide in 2024.
Farewell Europa Clipper, safe journeys to Jupiter's moon!
The Falcon Heavy putting on a spectacular show this afternoon as the NASA flagship missions begins a six year journey to the Jovian system!
Learn all about the mission from @NASASpaceflight : https://t.co/xb3vtb6Aiz pic.twitter.com/1S14GornAS
— Sawyer R. (@thenasaman) October 14, 2024
Falcon Heavy stands 70 m in height and masses around 1.4 million kg at liftoff. In a tri-core design, the bottom two-thirds of the rocket is comprised of three reusable Falcon boosters, with two side boosters and a central core. For Europa Clipper, the two side boosters were B1064-5 and B1065-5 — both of which were flying on their sixth flights and had previously launched NASA’s Psyche mission in 2023 — with B1089-1 serving as the center core and flying on its first mission. Due to the nature of Europa Clipper’s mission and its destination, all three Falcon boosters were expended and did not land on land at one of SpaceX’s landing zones or autonomous drone ships at sea. Each Falcon booster utilized nine Merlin 1D engines (27 total), which, together, produced approximately 22,000 kilonewtons of thrust. Falcon Heavy’s upper stage used a single Merlin 1D Vacuum engine, which produced approximately 934 kilonewtons of thrust.
Immediately following deployment, Europa Clipper teams checked the health of the spacecraft post-launch and established initial communications with the spacecraft. Additionally, Europa Clipper’s massive solar arrays were extended soon after deployment to ensure the spacecraft had enough power to perform its initial tasks.
We hear you, @EuropaClipper!
The Deep Space Network in Canberra, Australia, has acquired signal. This is the first indicator that we’re communicating with the spacecraft. Next up: Full telemetry! pic.twitter.com/ROXkSCXMIS
— NASA JPL (@NASAJPL) October 14, 2024
Europa Clipper is among the most anticipated missions of the 21st century and can confirm the habitability of another world within our solar system. Though it has been visited on multiple occasions and investigated hundreds — maybe even thousands — of times, much is still unknown about Europa and icy moons. Europa Clipper, along with JUICE, Juno, and other follow-up missions to the icy world, will provide scientists with a detailed look at a new kind of world, a world that could one day serve as a hub for human technology and development as humans continue to expand into our solar system and universe.
(Lead image: Falcon Heavy launching Europa Clipper to Jupiter. Credit: Julia Bergeron for NSF)