A Few Steps Closer to Europa: Spacecraft Hardware Makes Headway
In a clean room at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, Europa Clipper's propulsion module harness, installed onto a bake-out fixture, is rolled up to the propulsion module in preparation for transfer and installation. Pictured (from left) are Spencer Brock, Steve Wenrich, Devin Hahne, Doug Ramsey, Jaime Avendano and John Stinchcomb. Credit: Johns Hopkins APL/Ed Whitman
Mihaela Ballarotto samples Europa Clipper’s propulsion module for planetary protection cleanliness prior to harness installation. Credit: Johns Hopkins APL/Ed Whitman
The hardware that makes up NASA’s Europa Clipper spacecraft is rapidly taking shape, as engineering components and instruments are prepared for delivery to the main clean room at the agency’s Jet Propulsion Laboratory in Southern California. In workshops and labs across the country and in Europe, teams are crafting the complex pieces that make up the whole as mission leaders direct the elaborate choreography of building a flagship mission.
The massive 10-foot-tall (3-meter-tall) propulsion module recently moved from NASA’s Goddard Space Flight Center in Greenbelt, Maryland, to the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, where engineers will install electronics, radios, antennas and cabling. The spacecraft’s thick aluminum vault, which will protect Europa Clipper’s electronics from Jupiter’s intense radiation, is nearing completion at JPL. The building and testing of the science instruments at universities and partner institutions across the country continue as well.
The mission is also gearing up for its System Integration Review in late 2021, when NASA will review plans for assembling and testing Europa Clipper, and its instruments are inspected in detail. APL is developing the mission in partnership with JPL.
“It’s really exciting to see the progression of flight hardware moving forward this year as the various elements are put together bit by bit and tested,” said Europa Clipper Project Manager Jan Chodas of JPL. “The project team is energized and more focused than ever on delivering a spacecraft with an exquisite instrument suite that promises to revolutionize our knowledge of Europa.”
Jupiter’s icy moon Europa, which harbors an internal ocean with twice the amount of water in Earth’s oceans combined, may currently have conditions suitable for supporting life. Europa Clipper will carry a broad suite of science instruments into orbit around Jupiter and conduct multiple close flybys of Europa to gather data on its atmosphere, surface and interior.
HARDWARE IN THE WORKS
Delivery of the towering propulsion module from Goddard to APL marked a milestone for that major piece of hardware. APL built the twin cylinders that make up the module and shipped them to JPL, where technicians added thermal tubing that will carry coolant to keep the spacecraft from getting too hot or too cold in deep space. From there, the cylinders went to Goddard, where propellant tanks were installed inside of them and 16 rocket engines were attached to the outside.
Another large piece of hardware nearing completion is the spacecraft’s radiator, which connects to the thermal tubing. The width and length of a twin-size bed, the radiator’s 3-inch-thick (7.5-centimeter-thick) panel has the crucial job of radiating heat out into space to keep the spacecraft within its operating temperature range. It is covered with louvers that open and close automatically as the spacecraft disperses more or less heat to regulate its temperature.
Meanwhile, work at APL begins to integrate the propulsion module and the telecommunications hardware (electronics, radios, antennas and cabling). And construction of a high-gain antenna — a dish nearly 10 feet (3 meters) wide — is underway at vendor Applied Aerospace Structures Corporation in Stockton, California. It will be delivered to APL this year, where it will be integrated before the entire module comes back to JPL a final time. By the spring of 2022, the huge element will join other Europa Clipper hardware streaming into JPL’s main high bay for assembly, test and launch operations (ATLO).
One of the first elements in place for ATLO will be the spacecraft’s vault, now entering its final stage of fabrication at JPL. Eventually, the vault will be bolted to the top of the propulsion module and affixed with miles of cabling so that the power box and computer inside can communicate with the other subsystems.
Attached to the vault will be a deck, also completing assembly at JPL, that will support many of the instrument sensors. Called the nadir deck, it stabilizes the spacecraft’s sensors and helps ensure they are oriented correctly.
SCIENCE INSTRUMENTS NEARING COMPLETION
At the same time that the spacecraft body, electronics and engineering subsystems come together, nine science instruments are being assembled and tested across a network of clean rooms at NASA centers, partner institutions and private industry vendors. The suite of instruments will investigate everything from the depth of the internal ocean and its salinity to the thickness of the ice crust and potential plumes that may be venting subsurface water into space.
Slated to be delivered to ATLO from late 2021 through mid-2022, the instruments — which include APL-developed cameras to capture surface geology in detail and plasma sensors to study Europa’s ice thickness, ocean depth and conductivity — are undergoing extensive testing. Engineers want to be sure the instruments can communicate correctly with the flight computer, the spacecraft software and the power subsystem, to be able to respond to commands and transmit data back to Earth.
Mission leaders acknowledge that COVID-19 challenges have stretched the project and instrument teams as they find ways to meet deadlines when parts are delayed or staffing is short. Engineers, technicians and scientists continue to power through.
“What we’ve seen, even in the midst of the pandemic, is that the engineering and instrument teams are responding very well. The pandemic has affected mission schedule, but the teams are tackling the challenges, communicating openly and displaying tremendous flexibility to keep the hardware on track for our October 2024 launch,” said Europa Clipper Deputy Project Manager Jordan Evans. “We see it day in and day out, across the team, and it’s fantastic.”
MORE ABOUT EUROPA CLIPPER
Missions such as Europa Clipper contribute to the field of astrobiology, the interdisciplinary research on the variables and conditions of distant worlds that could harbor life as we know it. While Europa Clipper is not a life-detection mission, it will conduct detailed reconnaissance of Europa and investigate whether the icy moon, with its subsurface ocean, has the capability to support life. Understanding Europa’s habitability will help scientists better understand how life developed on Earth and the potential for finding life beyond our planet.
Managed by Caltech in Pasadena, California, JPL leads the development of the Europa Clipper mission in partnership with APL for NASA’s Science Mission Directorate in Washington. The Planetary Missions Program Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, executes program management of the Europa Clipper mission.
Quelle: THE JOHNS HOPKINS UNIVERSITY
----
Update: 8.10.2021
.
Astronomers Get Ready to Probe Europa’s Hidden Ocean for Life
Jupiter’s most enigmatic moon, one of a few ocean worlds in the solar system, will be the target of upcoming missions by NASA and the European Space Agency.
BEYOND MARS AND the asteroid belt, half a billion miles from the sun, the solar system might seem frigid, bleak, and lifeless. But scientists believe there’s a chance tiny alien creatures could reside on a distant moon, and you might find them if you look in the right place. For many researchers, that place is Europa, below its thick, icy crust.
Planetary scientists are discovering more about Jupiter’s fourth-largest moon, one of Earth’s nearest ocean worlds—places like Saturn’s moons Titan and Enceladus that have bodies of salty water and other liquids that could be amenable to the emergence of life. They’re presenting new findings this week about Europa’s cracked surface, hidden ocean, and geological activity at the biggest annual planetary conference in the United States, organized by the American Astronomical Society, held virtually for the second year in a row. The research serves as a prelude to tantalizing opportunities for new observations by upcoming NASA and European Space Agency missions.
“Europa is fantastic. Of anywhere in the solar system, outside the Earth, it has the greatest potential, I think, for maintaining a habitable environment that could support microbial life,” says Michael Bland, a US Geological Survey space scientist in Flagstaff, Arizona. After modeling the moon’s dynamic, rocky interior, Bland believes the conditions on its deep seafloor could be amenable to life, according to new work that he and NASA Jet Propulsion Laboratory scientist Catherine Elder presented at the conference on Monday.
Europa’s ocean is buried under about 10 miles of ice, but that doesn’t necessarily mean it’s too cold for life. As the moon orbits Jupiter, tidal forces generate heat that melts around 5 percent of the moon’s mantle, far below ground. Some of that magma could migrate up 100 miles through small cracks in the cold, rocky material above it, erupting onto the seafloor, Bland argues. If this process indeed happens, and frequently enough, it would function like hydrothermal vents do on Earth: These volcanic seafloor fissures provide the energy and chemical ingredients for life, far below the reach of sunlight and photosynthesis. Hardyorganismsthrive in such dark, high-pressure environments on our world, and perhaps they do on others as well.
But for the process to work, the magma has to reach the underground sea quickly, before it freezes and hardens. Its upward velocity might be just barely fast enough for it to work out that way, Bland’s models show, meaning there’s a chance for life on Europa’s seafloor. “It’s plausible, but specific conditions have to be met, and it’s not guaranteed,” he says.
Europa is considered one of Jupiter’s four Galilean moons, first spotted by Galileo Galilei with his pre-NASA telescope four centuries ago. Its compatriots include Io, a volcanic, sulfuric, radiation-bombarded wasteland close to Jupiter, and, orbiting further out beyond Europa, massive Ganymede and cratered Callisto. The latter two may harbor underground oceans, as well, but if so, the water would lie much deeper beneath even thicker crusts.
But Europa is unique. Not only is its crust relatively thin, but its surface is covered with thousands of narrow, criss-crossing ridges and crevices, some extending for hundreds of miles. By mapping currently available images, Michelle Babcock, a planetary scientist at Georgia Tech in Atlanta, identified around 70 “tortuous ridges” among them: wiggly, irregular structures unlike the straight and arced ridges scientists can already explain.
While they're not yet sure what causes the ridges’ convoluted paths, all the laceration marks on the moon’s exterior could originate in some way from its slightly elliptical orbit, which repeatedly carries it closer to—and then farther from—Jupiter. “As it’s orbiting Jupiter, the shell is being stretched and pulled, and that tidal stress is causing fractures and cracks, contributing to a lot of surface features,” Babcock says. They presented their findings with colleagues Britney Schmidt and Chase Chivers on Monday.
Such geological activity might play a role in explaining another mystery: Europa’s seemingly young surface. Unlike its neighbors, which have pockmarked appearances thanks to being pummeled by comets and asteroids for eons, Europa has few craters to show for its age. Somehow the moon is continually giving itself a facelift, and its many ridges could be involved in covering or erasing such craters over time, Babcock and their colleagues argue.
Other Europa-focused researchers at the conference are exploring which telltale signs of alien bacteria might be there, how such pivotal evidence could bubble up onto the surface or be spewed into space in plumes, as well as the effects of Jupiter’s radiation zapping the surface, which could destroy these signs of life before they’re found.
To definitively answer any of these questions, however, requires new space missions. Europa was last visited by a dedicated spacecraft—named in honor of its discoverer, Galileo—two decades ago. It made close passes by the moon and its neighbors and took images with its cameras in the process. Before that, Voyager 2 snapped photos as it flew by in 1979. NASA’s Juno spacecraft, which has been orbiting Jupiter since its arrival in 2016, will make some observations during flybys over the next couple of years. The European Space Agency’s JUICE probe, scheduled to launch next year, will do so as well, though it will be spending more time around Ganymede.
After that, Bland, Babcock, and their colleagues look forward to NASA’s Europa Clipper, a mission years in the making that’s planned for launch in 2024. “The Europa Clipper will assess Europa’s habitability and how we might be able to use these investigations for other ocean worlds, thinking about the potential for life there as well,” says Kathleen Craft, a planetary scientist at Johns Hopkins University Applied Physics Laboratory in Baltimore, who will be presenting at the conference on Thursday.
The car-sized orbiter, with 100-foot solar panels unfurled on each side, will use radar, radio signals, and gravity science to study the structure of the moon, including measuring the thickness of the ice shell and the depth of the underground ocean. It will also try to snag samples from its plumes, which could include droplets from the ocean itself that might reveal information about how conducive to life it really is, Craft says. A baguette-sized instrument will ingest gas and vapor, analyze and classify the contents, and then beam the crucial data back to scientists at home.
Its mission also includes conducting aerial surveillance for a potential lander mission to Europa, which could scoop up material on the surface, or drill down for it, looking for that coveted evidence of extraterrestrial lifeforms.
To prepare for a future lander, researchers are scoping out somewhat similar places on Earth, such as in Greenland. Satellite imagery of proxy places like these will give them a realistic idea of what Europa’s terrain will be like, and that’s crucial, because right now their photos don’t have high enough resolution. And that could be dangerous: An icy region that might suggest a smooth landing place could hide a more complexly structured glacier, with smaller, unseen hazards. “But it’s a completely alien environment,” says Curt Niebur, NASA’s lead scientist for Planetary Science Flight Programs and Europa Clipper program scientist.
They will have to weigh the scientific value of a landing site—one with good odds of showcasing signs of life—versus the risk involved in touching down there. “Invariably, scientists say, ‘The most interesting spot to land is over there,’ and the engineers say, ‘We will blow up if we try to land there,’” he says.
Before Niebur and his colleagues can nail down the details of where the lander will go and how it will touch down, they need high-resolution images, better than anyone has yet, because landing in the wrong spot could scuttle the long-term investment in research and development leading up to such a flagship mission. Imagine, he says, if aliens sent a poorly placed probe to Earth, which sampled the wrong part of the ocean and only got a teaspoon’s worth of lifeless water. That’s why, he says, “everything hinges on Europa Clipper.”
Quelle: WIRED
----
Update: 4.03.2022
.
NASA Begins Assembly of Europa Clipper Spacecraft
Clockwise from left: the propulsion module for NASA’s Europa Clipper, the ultraviolet spectrograph (called Europa-UVS), the high-gain antenna, and an illustration of the spacecraft. Credit: NASA/JPL-Caltech / Johns Hopkins APL
Science instruments and other hardware for the spacecraft will come together in the mission’s final phase before a launch to Jupiter’s icy moon Europa in 2024.
When it’s fully assembled, NASA’s Europa Clipper will be as large as an SUV with solar arrays long enough to span a basketball court – all the better to help power the spacecraft during its journey to Jupiter’s icy moon Europa. And just about every detail of the spacecraft will have been hand-crafted.
The assembly effort is already underway in clean rooms at the agency’s Jet Propulsion Laboratory in Southern California. Now, engineering components and science instruments are beginning to stream in from across the country and Europe. Before year’s end, most of the flight hardware – including a suite of nine science instruments – is expected to be complete.
The main body of the spacecraft is a giant 10-foot-tall (3-meter-tall) propulsion module, designed and constructed by Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, with help from NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and JPL. The module, fitted with electronics, radios, cabling, and the propulsion subsystem, will ship to JPL this spring. Europa Clipper’s 10-foot-wide (3-meter-wide) high-gain antenna also will be arriving at the Lab soon.
“We’re moving into the phase where we see the pieces all come together as a flight system,” said Europa Clipper Project Manager Jan Chodas of JPL. “It will be very exciting to see the hardware, the flight software, and the instruments get integrated and tested. To me, it’s the next level of discovery. We’ll learn how the system we designed will actually perform.”
Europa, which scientists are confident harbors an internal ocean with twice the amount of water in Earth’s oceans combined, may currently have conditions suitable for supporting life. Europa Clipper will orbit Jupiter and conduct multiple close flybys of Europa to gather data on the moon’s atmosphere, surface, and interior. Its sophisticated payload will investigate everything from the depth and salinity of the ocean to the thickness of the ice crust to the characteristics of potential plumes that may be venting subsurface water into space.
An engineer inspects the radio frequency (RF) panel of NASA's Europa Clipper in a cleanroom at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland.
Credit: Johns Hopkins APL
The first science instrument to be completed was delivered to JPL last week by a team at Southwest Research Institute in San Antonio, Texas. The ultraviolet spectrograph, called Europa-UVS, will search above the surface of Europa for signs of plumes. The instrument collects ultraviolet light, then separates the wavelengths of that light to help determine the composition of the moon’s surface and gases in the atmosphere.
As each instrument arrives at JPL, it will be integrated with the spacecraft and re-tested. Engineers need to be sure the instruments can communicate with the flight computer, spacecraft software, and the power subsystem.
Once all the components have been integrated to form the large flight system, Europa Clipper will move to JPL’s enormous thermal vacuum chamber for testing that simulates the harsh environment of deep space. There also will be intense vibration testing to ensure Europa Clipper can withstand the jostling of launch. Then it’s off to Cape Canaveral, Florida, for an October 2024 launch.
For the leaders of this mission, seeing the engineering components come together with the fleet of instruments will be especially moving, knowing how hard their teams have pushed to work through the coronavirus pandemic.
“I don’t know how I’ll feel, seeing this come together. I suspect it will be somewhat overwhelming,” said JPL’s Robert Pappalardo, the Europa Clipper project scientist. “It’s happening – it’s becoming real. It’s becoming tangible.”
At the same time, the level of difficulty kicks up several notches as the layers of the project merge.
“All of the parallel paths of hardware and software development will start to join together in a way that’s very visible to the team,” said JPL’s Jordan Evans, the deputy project manager. “Everybody’s eyes turn toward the integrated system that’s coming together, which is exciting.”
More About the Mission
Missions such as Europa Clipper contribute to the field of astrobiology, the interdisciplinary research on the variables and conditions of distant worlds that could harbor life as we know it. While Europa Clipper is not a life-detection mission, it will conduct detailed reconnaissance of Europa and investigate whether the icy moon, with its subsurface ocean, has the capability to support life. Understanding Europa’s habitability will help scientists better understand how life developed on Earth and the potential for finding life beyond our planet.
Managed by Caltech in Pasadena, California, JPL leads the development of the Europa Clipper mission in partnership with APL for NASA’s Science Mission Directorate in Washington. The Planetary Missions Program Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, executes program management of the Europa Clipper mission.
Quelle: NASA
----
Update: 10.03.2022
.
SpaceX’s first Jupiter launch a step closer as NASA begins assembling ‘Europa Clipper’
NASA says that the assembly of Europa Clipper has begun at NASA’s Jet Propulsion Laboratory (JPL), in Southern California.
Europa Clipper is an interplanetary spacecraft developed by NASA to observe Europa, a large moon of Jupiter, over the course of a series of flybys while orbiting the gas giant. The Clipper’s primary goal is to determine whether Europa hosts conditions suitable for life in an immense liquid water ocean that lies under its icy surface. NASA has selected SpaceX to launch the ~$4.25 billion spacecraft to Jupiter in 2024 on its Falcon Heavy rocket – a contract SpaceX effectively beat out NASA’s own Space Launch System (SLS) rocket to win.
The engineering components and science instruments that make up the spacecraft’s flight hardware began development in 2016 and are expected to be completed by the end of 2022. These components come from across the United States and Europe and will be assembled at JPL. The main body of the spacecraft is a 10-foot-tall (3-meter-tall) cylindrical propulsion module. Fitted with electronics, radios, cables, and the spacecraft’s propulsion systems, it will ship to JPL this spring. Europa Clipper’s 10-foot-wide (3-meter-wide) high-gain antenna is expected to follow not long after.
The first instrument to arrive at JPL was the Europa-UVS, an ultraviolet spectrograph that was assembled in San Antonio, Texas. Europa-UVS will search above the surface of Europa for signs of plumes. The instrument collects ultraviolet light, then separates the wavelengths of that light to help determine the composition of the moon’s surface and gases in the atmosphere.
As components of the spacecraft arrive, they will be integrated together and re-tested. Engineers need to be sure the instruments can communicate with the flight computer, spacecraft software, and power subsystems.
“Once all the components have been integrated to form the large flight system, Europa Clipper will move to JPL’s enormous thermal vacuum chamber for testing that simulates the harsh environment of deep space. There also will be intense vibration testing to ensure Europa Clipper can withstand the jostling of launch. Then it’s off to Cape Canaveral, Florida, for an October 2024 launch.”
According to NASA, “when it’s fully assembled, Europa Clipper will be as large as an SUV [and have] solar arrays long enough to span a basketball court – all the better to help power the spacecraft during its journey to Jupiter’s icy moon Europa.”
Previous imagery has already provided scientists with certainty that Europa’s surface is made up of mostly water ice. Additionally, other data about the moon’s physical characteristics have engendered great confidence that beneath or within some of that 15-mile-thick ice lies pockets of liquid water that could go thousands of years between re-freezing events. Those water pockets could potentially be habitable and even contain microbial life that Europa Clipper could detect.
The icy crust of Jupiter’s fourth-largest moon, Europa, may hold pockets of liquid water that could support life.
Some scientists like Monica Grady, Chancellor at Liverpool Hope University, believe it is almost certain that Europa is harboring life. “When it comes to the prospects of life beyond Earth, it’s almost a racing certainty that there’s life beneath the ice on Europa,” stated Grady in 2020.
NASA says that “Europa Clipper will orbit Jupiter and conduct multiple close flybys of Europa to gather data on the moon’s atmosphere, surface, and interior. Its sophisticated payload will investigate everything from the depth and salinity of the ocean to the thickness of the ice crust to the characteristics of potential plumes that may be venting subsurface water into space.”
Falcon Heavy, 2019. (SpaceX)
Europa Clipper will be carried into space aboard a SpaceX Falcon Heavy rocket, the most powerful operational rocket today. The ~$178 million launch contract was announced on July 23rd, 2021. Following a tentative Q4 2024 launch into heliocentric (sun-orbiting) space, Europa Clipper will spend around three years in deep space, performing gravity-assist maneuvers at Earth and Mars to eventually boost itself to Jupiter for a 2028 arrival.
Quelle: TESLARATI
----
Update: 9.06.2022
.
NASA’s Europa Clipper Mission Completes Main Body of the Spacecraft
Europa Clipper's Core
NASA's Europa Clipper spacecraft is visible in a main clean room at JPL, as engineers and technicians inspect it just after delivery in early June 2022. Credit: NASA/JPL-Caltech/Johns Hopkins APL/Ed Whitman
The agency’s mission to explore Jupiter’s icy moon takes a big step forward as engineers deliver a major component of the spacecraft.
The main body of NASA’s Europa Clipper spacecraft has been delivered to the agency’s Jet Propulsion Laboratory in Southern California. Over the next two years there, engineers and technicians will finish assembling the craft by hand before testing it to make sure it can withstand the journey to Jupiter’s icy moon Europa.
The spacecraft body is the mission’s workhorse. Standing 10 feet (3 meters) tall and 5 feet (1.5 meters) wide, it’s an aluminum cylinder integrated with electronics, radios, thermal loop tubing, cabling, and the propulsion system. With its solar arrays and other deployable equipment stowed for launch, Europa Clipper will be as large as an SUV; when extended, the solar arrays make the craft the size of a basketball court. It is the largest NASA spacecraft ever developed for a planetary mission.
“It’s an exciting time for the whole project team and a huge milestone,” said Jordan Evans, the mission’s project manager at JPL. “This delivery brings us one step closer to launch and the Europa Clipper science investigation.”
Set to launch in October 2024, Europa Clipper will conduct nearly 50 flybys of Europa, which scientists are confident harbors an internal ocean containing twice as much water as Earth’s oceans combined. And the ocean may currently have conditions suitable for supporting life. The spacecraft’s nine science instruments will gather data on Europa’s atmosphere, surface, and interior – information that scientists will use to gauge the depth and salinity of the ocean, the thickness of the ice crust, and potential plumes that may be venting subsurface water into space.
This video captures the delivery of the core of NASA’s Europa Clipper spacecraft to the agency’s Jet Propulsion Laboratory in Southern California. The Johns Hopkins Applied Physics Laboratory designed and built the spacecraft body in collaboration with JPL and NASA’s Goddard Space Flight Center.
Credit: NASA/JPL-Caltech
Those instruments already have begun arriving at JPL, where the phase known as assembly, test, and launch operations has been underway since March. The ultraviolet spectrograph, called Europa-UVS, arrived in March. Next came the spacecraft’s thermal emission imaging instrument, E-THEMIS, delivered by the scientists and engineers leading its development at Arizona State University. E-THEMIS is a sophisticated infrared camera designed to map Europa’s temperatures and help scientists find clues about the moon’s geological activity – including regions where liquid water may be near the surface.
By the end of 2022, most of the flight hardware and the remainder of the science instruments are expected to be complete.
The Whole Package
The Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, designed Europa Clipper’s body in collaboration with JPL and NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The flight system designed, built, and tested by APL – using a team of hundreds of engineers and technicians – was the physically largest system ever built by APL,” said APL’s Tom Magner, the mission’s assistant project manager.
The main body of NASA's Europa Clipper spacecraft is seen in its shipping container as it rolls into the agency's Jet Propulsion Laboratory in Southern California.
“What arrived at JPL represents essentially an assembly phase unto itself. Under APL’s leadership, this delivery includes work by that institution and two NASA centers. Now the team will take the system to an even higher level of integration,” said Evans.
The main structure is actually two stacked aluminum cylinders dotted with threaded holes for bolting on the spacecraft’s cargo: the radio frequency module, radiation monitors, propulsion electronics, power converters, and wiring. The radio frequency subsystem will power eight antennas, including an enormous high-gain antenna that measures 10 feet (3 meters) wide. The structure’s web of electrical wires and connectors, called the harness, weighs 150 pounds (68 kilograms) by itself; if stretched out, it would run almost 2,100 feet (640 meters) – twice the perimeter of a football field.
The heavy-duty electronics vault, built to withstand the intense radiation of the Jupiter system, will be integrated with the main spacecraft structure along with the science instruments.
Inside the main body of the spacecraft are two tanks – one to hold fuel, one for oxidizer – and the tubing that will carry their contents to an array of 24 engines, where they will combine to create a controlled chemical reaction that produces thrust.
“Our engines are dual purpose,” said JPL’s Tim Larson, the deputy project manager. “We use them for big maneuvers, including when we approach Jupiter and need a large burn to be captured in Jupiter’s orbit. But they’re also designed for smaller maneuvers to manage the attitude of the spacecraft and to fine tune the precision flybys of Europa and other solar system bodies along the way.”
Those big and small maneuvers will come into play a lot during the six-year, 1.8-billion-mile (2.9-billion-kilometer) journey to this ocean world, which Europa Clipper will begin investigating in earnest in 2031.
Quelle: NASA
----
Update: 14.06.2022
.
Europa Clipper’s main body complete, teams continue work toward 2024 launch
In early June, the main body of NASA’s upcoming Europa Clipper spacecraft completed construction and was shipped to NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California soon after. The arrival of Europa Clipper’s main body marks a major milestone in the construction of the spacecraft and shows that the spacecraft and its teams are on track for a launch in 2024.
“It’s an exciting time for the whole project team and a huge milestone. This delivery brings us one step closer to launch and the Europa Clipper science investigation,” said Europa Clipper project manager Jordan Evans of JPL.
While the construction of the spacecraft’s main body is complete, that does not mean construction of the spacecraft as a whole is finished. Numerous mission-critical components are yet to be assembled and installed onto the spacecraft.
Europa Clipper’s main body is large, measuring three meters tall and 1.5 meters wide, and is constructed of aluminum. Additionally, the main body is cylindrical in shape and is already integrated with many electronics, radios, thermal loop tubing, cabling, and propulsion systems which are set to be used during the course of its nearly 10-year-long mission at Jupiter.
The main module itself is two aluminum cylinders stacked on top of one another. Each cylinder is dotted with threaded holes that will be used to attach Europa Clipper’s instruments and other spacecraft systems.
Overall, Europa Clipper’s radio frequency module will power eight antennas that will be used to communicate with Earth and other spacecraft. One of these eight antennas is the mission’s large high-gain antenna. Measuring three meters wide, this high-gain antenna will be used to send data back and forth between Earth and Jupiter at fast rates.
Another system attached to Europa Clipper’s main body is its web of connectors and electrical wires. Called the harness, there are more than 640 meters wires and connectors, weighing 68 kilograms.
Europa Clipper’s heavy-duty electronics vault will carry some of the major electronics needed for the mission and is designed to withstand the immense radiation of Jupiter and its surrounding moons. It will be integrated with the main module alongside some of the mission’s science instruments at JPL.
Also inside the main module are two tanks that will hold the spacecraft’s fuel. One tank will hold fuel and the other will hold oxidizer. Additionally, the tubing used to carry the fuel from the tanks to Europa Clipper’s 24 engines is stored inside the main module.
The spacecraft’s 24 engines will be used to perform mission-critical maneuvers when traveling to and while at Jupiter.
“Our engines are dual-purpose,” said JPL’s Tim Larson, the deputy project manager. “We use them for big maneuvers, including when we approach Jupiter and need a large burn to be captured in Jupiter’s orbit. But they’re also designed for smaller maneuvers to manage the attitude of the spacecraft and to fine tune the precision flybys of Europa and other solar system bodies along the way.”
The main body of Europa Clipper was designed and developed by the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, in partnership with JPL and the Goddard Space Flight Center.
What lies ahead
Now that the main body is at JPL, engineers will continue to work on and prepare the main module for final testing and launch.
“What arrived at JPL represents essentially an assembly phase unto itself,” said Evans. “Under APL’s leadership, this delivery includes work by that institution and two NASA centers. Now the team [at JPL] will take the system to an even higher level of integration.”
The nine science instruments of Europa Clipper. (Credit: NASA/JPL-Caltech)
Evidence so far analyzed from other observations indicate the presence of a large subterranean ocean on Europa, containing twice the amount of water as Earth’s oceans. What’s more, conditions in this internal ocean may currently be suitable for supporting life.
In fact, one of Europa Clipper’s main science objectives is to study and confirm that this massive ocean exists.
To do this, Europa Clipper will carry nine science instruments to study Europa, including the Europa Thermal Emission Imaging System (E-THEMIS), Mapping Imaging Spectrometer for Europa (MISE), Europa Imaging System (EIS), Europa Ultraviolet Spectrograph (Europa-UVS), Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON), Interior Characterization of Europa using Magnetometry (ICEMAG), Plasma Instrument for Magnetic Sounding (PIMS), Mass Spectrometer for Planetary Exploration (MASPEX), and the Surface Dust Analyzer (SUDA).
Many of Europa Clipper’s instruments have already been assembled, shipped, and delivered to JPL and are awaiting integration onto their respective locations on the spacecraft. This phase of development, known as assembly, test, and launch operations, has been underway since March 2022.
By the end of 2022, much of — if not all of — Europa Clipper’s flight hardware and instruments are expected to be completed and shipped to JPL.
