From its halo-like orbit nearly a million miles from Earth, the James Webb Space Telescope is seeing farther than human eyes have ever seen.
In May, astronomers announced that Webb detected the most distant galaxy found so far, a fuzzy blob of red light that we see as it existed just 290 million years after the Big Bang. Light from this galaxy, several hundreds of millions of times the mass of the Sun, traveled more than 13 billion years until photons fell onto Webb's gold-coated mirror.
A few months later, in July, scientists released an image Webb captured of a planet circling a star slightly cooler than the Sun nearly 12 light-years from Earth. The alien world is several times the mass of Jupiter and the closest exoplanet to ever be directly imaged. One of Webb's science instruments has a coronagraph to blot out bright starlight, allowing the telescope to resolve the faint signature of a nearby planet and use spectroscopy to measure its chemical composition.
For those who follow NASA's human spaceflight program, when the Orion spacecraft's heat shield cracked and chipped away during atmospheric reentry on the unpiloted Artemis I test flight in late 2022, what caused it became a burning question.
Multiple NASA officials said Monday they now know the answer, but they're not telling. Instead, agency officials want to wait until more reviews are done to determine what this means for Artemis II, the Orion spacecraft's first crew mission around the Moon, officially scheduled for launch in September 2025.
"We have gotten to a root cause," said Lakiesha Hawkins, assistant deputy associate administrator for NASA's Moon to Mars program office, in response to a question from Ars on Monday at the Wernher von Braun Space Exploration Symposium in Huntsville, Alabama.
For his most recent trip to the International Space Station, in lieu of bringing coffee or some other beverage in his "personal drink bag" allotment for the stay, NASA astronaut Don Pettit asked instead for a couple of bags of unflavored gelatin.
This was not for cooking purposes but rather to perform scientific experiments. How many of us would give up coffee for science?
NASA said Saturday that an astronaut who was hospitalized after returning from space the day before has been released and is in "good health." The agency did not provide any more details on the matter, citing medical privacy protections.
The astronaut was one of four crew members who returned from a 235-day mission in low-Earth orbit with a predawn splashdown Friday. The four-person crew splashed down inside SpaceX's Crew Dragon Endeavour spacecraft at 3:29 am EDT (07:29 UTC) in the Gulf of Mexico south of Pensacola, Florida.
Commander Matthew Dominick, pilot Michael Barratt, mission specialist Jeanette Epps, and Russian cosmonaut Alexander Grebenkin were inside SpaceX's Dragon spacecraft for reentry and splashdown. NASA said one of its astronauts "experienced a medical issue" after the splashdown, and all four crew members were flown to Ascension Sacred Heart Pensacola for medical evaluation.
Sometimes, it's worth noting when something goes unsaid.
On Wednesday, Boeing's new CEO, Kelly Ortberg, participated in his first quarterly conference call with investment analysts. Under fire from labor groups and regulators, Boeing logged a nearly $6.2 billion loss for the last three months, while the new boss pledged a turnaround for the troubled aerospace company.
What Ortberg didn't mention in the call was the Starliner program. Starliner is a relatively small portion of Boeing's overall business, but it's a high-profile and unprofitable one.
Yesterday, NASA successfully launched the Europa Clipper, the largest spacecraft the agency has ever built for a planetary mission. Clipper is now successfully on its multi-year journey to Europa, bristling with equipment to study the Jovian moon’s potential to support life—but just a few months ago, the mission was almost doomed. In July, researchers at NASA found out that a group of Europa Clipper’s transistors would fail under Jupiter’s extreme radiation levels. They spent months testing devices, updating their flight trajectories, and ultimately adding a warning “canary box” to monitor the effects of radiation as the mission progresses.
The canary box “is a very logical engineering solution to a problem,” says Alan Mantooth, an IEEE Fellow and a professor of electrical engineering at the University of Arkansas. But ideally, it wouldn’t have been needed at all. If NASA had caught the issues with these transistors earlier or designed their circuits with built-in monitoring, this last minute scramble wouldn’t have occurred. “It’s a clever patch,” says Mantooth, “but it’s a patch.”
Scientists have been “radiation hardening” electronics—designing them to function in a radioactive environment—since the 1960s. But as missions to space become more ambitious, radiation hardening techniques have had to evolve. “It’s kind of like cybersecurity,” says Mantooth. “You’re always trying to get better. There’s always a more harsh environment.”
With the rapid acceleration of companies like SpaceX, the space industry is at “a massive inflection point,” says Eric Faraci, an engineer at Infineon who works on aerospace and defense projects. “Everything we used to take for granted about how you do something, what’s accepted, best practices—everything’s been questioned.”
In future space exploration, we’ll see more systems made with alternative semiconductors like silicon carbide, specialized CMOS transistors, integrated photonics, and new kinds of radiation-resistant memory. Here’s your guide to the next generation of radiation hardened technology.
Silicon Carbide’s Ultra Wide Band Gap
Most power devices in spacecraft today use silicon as the semiconductor, but the next generation will use silicon carbide, says Enxia Zhang, a researcher at the University of Central Florida who has been developing radiation hard microelectronics for over 20 years. Silicon carbide is more resistant to radiation because of its wider band gap, which is the extra energy electrons need to transition from being bound to an atom’s nucleus to participating in conduction. Silicon has a band gap of 1.1 electron volts, while silicon carbide’s ranges from 3.3 to 3.4 eV. This means that more energy is required to disturb an electron of silicon carbide, so it’s less likely that a dose of stray radiation will manage to do it.
Silicon carbide chips are being manufactured right now, and NASA holds a weekly meeting to test them for space missions, says Zhang. NASA’s silicon carbide devices are expected to be used on missions to the Moon and Venus in the future.
“People are flying silicon carbide” devices right now, says Infineon’s Faraci. They are getting around a lack of standards by using them at parameters well below what they are designed for on Earth, a technique called derating.
Another semiconductor with a suitably wide band gap is gallium nitride (3.2 eV). Most commonly found in LEDs, it is also used in laptop chargers and other lower power consumer electronics. While it’s a “very exciting” material for space applications, it’s still a new material, which means it has to go through a lot of testing to be trusted, says Faraci.
Gallium nitride is best suited for cold temperatures, like on Mars or the dark side of the Moon, says Mantooth. But “if we’re doing something on Mercury or we’re doing something close to the Sun—any high temperature stuff … silicon carbide’s your winner.”
Silicon on Insulator Designs and FinFETs for Designing Radiation-Hardened CMOS
New materials aren’t the only frontier in radiation hardening; researchers are also exploring new ways of designing silicon transistors. Two CMOS production methods are already have a radiation hardened form: silicon on insulator (SOI), and fin field effect transistors (FinFETs). Both methods are designed to prevent a kind of radiation damage called single event effects, where a high energy particle hits an electronic device, jolting its electrons into places they shouldn’t be and flipping bits.
In ordinary bulk CMOS, current flows from the source to the drain through the channel, with a gate acting as a switch, blocking or allowing the current’s flow. These sit in the top layer of silicon. Radiation can excite charges deeper down in the silicon bypassing the gate’s control and allowing current to flow when it shouldn’t. Radiation hardening methods work by impeding the movement of these excited electrons.
SOI designs add a layer of an insulator like silicon oxide below the source and the drain, so that charges cannot flow as easily below the channel. FinFET designs raise the drain, source, and the channel between them into one or more 3D “fins”. Excited charges now have to flow down, around, and back up in order to bypass the gate. FinFETs are also naturally resistant to another form of radiation damage: the total ionizing dose, which occurs when a slow buildup of charged particles changes the properties of the insulating layer between the channel and gate of a device.
The techniques to produce SOI devices and FinFETs have existed for decades. In the 2000s, they weren’t used as much in radiation hardening, because circuit designers could still use ordinary, bulk CMOS devices, mitigating radiation risks in their circuit design and layout, according to Hugh Barnaby, a professor of electrical engineering at Arizona State University. But lately, as CMOS devices have gotten smaller and therefore more vulnerable to radiation, there’s been renewed interest in producing these naturally radiation hard varieties of CMOS devices, even if they are more specialized and expensive.
Barnaby is working with a team on improving radiation hardness in FinFETs. They found that adding more fins increased the device’s ability to control current, but reduced its radiation hardness. Now they are working to rearrange where the fins are to maximize the effectiveness of radiation resistant circuits. “We haven’t done this quite yet,” says Barnaby, “but I’m sure it will work.”
Photonic Systems for High Bandwidth, Faster Data Transfer
Photonic systems use light instead of electrons to transfer information over long distances with little energy. For example, the Internet uses optical fibers to quickly transfer large amounts of data. Within the last decade, researchers have developed silicon photonics integrated circuits which are currently used for high bandwidth information transmission in data centers, but would also enable us to move high volumes of data around in spacecraft, according to John Cressler, a professor of electronics at Georgia Tech.
“If you think of some of the systems that are up in space, either maybe they’re remote sensing or communication,” says Cressler, “they have a lot of data that they’re gathering or moving and that’s much easier to do in photonics.”
The best part? Photonics integrated circuits are naturally radiation hard, because their data transfer is done using photons instead of electrons. A high energy dose of radiation won’t disrupt a photon as it would an electron, because photons are not electrically charged.
Cressler anticipates that integrated photonics will be used in spacecraft in the next two years. “NASA and the [U.S. Department of Defense] and even commercial space [companies] are very interested in photonics,” he says.
Nonvolatile Memory in Space
Another promising area of research for radiation hardness in space is new kinds of nonvolatile memory. Computers usually use static random access memory (SRAM) or dynamic random access memory (DRAM). These are volatile memories, which means once the power is off, they cannot store their state. But nonvolatile memories are able to remember their state. They don’t require continuous power, and therefore reduce power consumption needs.
There are two front-runners in nonvolatile memory for use in space: Magnetoresistive-RAM (MRAM), and Resistive-RAM (ReRAM). MRAM uses magnetic states to store data, and ReRAM uses a quality called memristance. Both technologies are radiation hard simply by how they are designed; radiation won’t affect the magnetic fields of MRAM or the resistances of ReRAM.
“Resistive RAM is one of the technologies that has the potential to get to neuromorphic, low energy computing,” says Michael Alles, the director of the Institute for Space and Defense Electronics at Vanderbilt University, referring to a form of computing inspired by how brains work. Satellites usually are not equipped with the ability to process much of their own data, and have to send it back to Earth. But with the lower power consumption of memristor-based circuits, satellites could do computations onboard, saving communications bandwidth and time.
Though still in the research phases, Zhang predicts we will see nonvolatile memory in space in the next 10 to 15 years. Last year, the U.S. Space Force contracted Western Digital $35 million dollars to develop nonvolatile radiation hardened memory.
A Note of Caution and Hope
Alles cautions, however, that the true test for these new technologies will not be how they do on their own, but rather how they can be integrated to work as a system. You always have to ask: “What’s the weak link?” A powerful and radiation hard memory device could be for naught, if it depends on a silicon transistor that fails under radiation.
As space exploration and satellite launches continue to ramp up, radiation hardening will only become more vital to our designs. “What’s exciting is that as we advance our capabilities, we’re able to go places we haven’t been able to go before and stay there longer,” says Mantooth. “We can’t fly electronics into the Sun right now. But one day, maybe we will.”
Europa is slightly smaller than Earth’s own moon and is one of the most fascinating and mysterious objects in the solar system. One of Jupiter’s four Galilean moons, Europa’s crust is a largely crater-free shell of ice, somewhere between tens and more than a hundred kilometers thick. Crisscrossed with streaks and fractures, and formed by unique processes, the ice hides beneath it a suspected ocean of uncertain depths and untold mysteries.
Europa is also shrouded in Jupiter’s unforgiving radiation belts. Thus, delving into the moon’s secrets—the very existence of which were hinted at by brief visits by both Voyager probes, as well as Galileo and Juno—requires a fair amount of ingenuity and resilience. NASA’s US $5 billion Europa Clipper mission is now en route, poised to tackle these challenges and address one of astrobiology’s most profound questions: Does Europa have the potential to harbor life?
The spacecraft launched on 14 October, after a short delay due to Hurricane Milton, some concerns over spacecraft transistors found to be failing at lower radiation doses than expected, and a multi-decade battle for political and budgetary backing. The spacecraft will reach Europa, some 700 million kilometers away, in 2030. Clipper will not orbit Europa, but make 49 flybys of the moon—more if the hardware holds out and the mission is extended—swinging in once every three weeks for approaches as close as 25 kilometers above the surface, and then heading back out beyond the intense, electronics-killing belts of radiation to prolong the mission.
Clipper is packed with a suite of nine instruments—imagers, spectrometers, magnetometers and radar—geared towards the key question of Europa’s habitability. Together, these instruments will build a multidimensional view of this icy jewel and, crucially, how it works. While not being able to detect life below the ice, the payloads will work in concert to determine whether or not life could develop there and elsewhere in the solar system.
SUrface Dust Analyzer (SUDA)
Europa’s lack of atmosphere means micrometeorites smack right into the moon’s surface. These small collisions send dust out into space. SUDA, a spectrometer, will scoop up this ejecta and, as these particles pass through metal mesh grids, determine the dust’s speed and trajectory, as well as its mass and composition.
By doing this, SUDA will tell researchers the composition of the ice and the salts present on Europa’s surface as well as clues to what lies below. Together with magnetic field measurements, this will help determine the depth of the ocean and the minerals present on its floor.
Beyond this, SUDA’s sensitivity will give far greater insight into what may be happening on Europa and whether it’s habitable.
“SUDA shines when it comes to identifying tiny traces of organics embedded in ice,” says Sascha Kempf, SUDA’s principal investigator and a planetary scientist at University of Colorado-Boulder. It is able to measure organic molecules at the parts per million level. SUDA’s sensitivity allows it to establish ratios of, for example, amino acids, and help determine if this would indicate a non-biological process or potentially an organism producing healthy amino acids.
MAss Spectrometer for Planetary EXploration/Europa (MASPEX)
Like SUDA, MASPEX is a spectrometer, but geared to analyzing the thin exosphere of gasses surrounding Europa and its chemical environment, seeking out elements necessary for life as we know it with unprecedented resolution. MASPEX would also be able to analyze material vented into space by suspected Europa water plumes, uncover signs of active geological processes or even detect potential biosignatures.
Europa Clipper Magnetometer (ECM)
ECM features a 8.5-meter-long boom which will detect and analyze any induced magnetic fields created by the interaction between Jupiter’s magnetic field and Europa’s subsurface ocean—if it is salty and producing electric currents. ECM aims to provide insights into the depth, salinity, and extent of the ocean beneath the ice, as well as if the ocean is interacting with the icy crust: A process likely necessary to create an environment conducive to life.
Plasma Instrument for Magnetic Sounding (PIMS)
PIMS is designed to measure the density and behavior of charged particles in Europa’s ionosphere and the surrounding plasma environment. Combined with magnetometer data from ECM, readings from PIMS will help determine how Europa’s subsurface ocean interacts with Jupiter’s magnetic field. By doing this, PIMS aims to ascertain the depth and conductivity of Europa’s ocean, as well as the thickness of the ice shell.
Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON)
REASON’s antennas will ping the surface with signals and catch the echoes with huge booms half the size of a basketball court, which will be deployed after liftoff. The reflected signals will allow the team to build a picture of Europa’s subsurface, determining the depth of the ice and where the theorized ocean begins—as well as any lakes in between—and help study Europa’s topography and composition.
“Planetary science has been an X-Y science,” says Don Blankenship, a research professor at the University of Texas Institute for Geophysics and principal investigator for REASON, referring to a two-dimensional coordinate system. “We’re bringing the vertical. We’re bringing the subsurface to planetary science.”
The payload will also help uncover evidence for the processes of any exchange between the ice and ocean below and the likelihood for chemistry that could support life.
“You’ve got reductants down below, hopefully, present in the ocean, and then oxidants at the surface. The organizing principle has to be the exchange. How does the surface get into the ocean? And how does the ocean get into the icy shell? And that’s why the radar is so important,” says Blankenship.
Mapping Imaging Spectrometer for Europa (MISE)
MISE will analyze infrared light reflected from Europa, measuring how different materials absorb and reflect sunlight at specific wavelengths and thus mapping water ice, salts, organics and minerals across the surface. Materials found near cracks and fractures will provide insight into how material may be exchanged between the surface and churning subsurface ocean.
Europa Ultraviolet Spectrograph (Europa-UVS)
Europa-UVS will collect ultraviolet light to study Europa’s surface and exosphere, and search for molecules of hydrogen, oxygen, hydroxide, and carbon dioxide. It will also hunt for evidence of plumes expelling material out into space.
Europa Thermal Emission Imaging System (E-THEMIS)
E-THEMIS will capture infrared wavelengths in fine spatial detail to map Europa’s surface temperatures, giving insight into night and day dynamics, identifying potential subsurface heat sources and indicators of geological activity and even eruptions of plumes or shifts in the icy crust.
Europa Imaging System (EIS)
EIS consists of one wide-angle and one narrow-angle camera, each with an eight-megapixel sensor spanning near-infrared, optical, and a small portion of ultraviolet frequencies. It will map Europa’s surface by capturing stereoscopic images at 100 meters per pixel, bringing new views and uncovering new terrain and features such as ridges, cracks, and potential active regions in unprecedented resolution.
“With Europa’s unique geology, we really want to understand the nature of the ice shell and the geologic processes acting within that ice shell,” says Elizabeth “Zibi” Turtle, a planetary scientist at Johns Hopkins Applied Physics Laboratory and EIS’ principal investigator.
REASON and EIS will combine to provide a data set to gain a three-dimensional understanding of the ice shell, with surface topography and subsurface imaging.
EIS will also look for plumes of water escaping the surface. Imaging the boundary between day and night on Europa could reveal plumes ejected from the nightside but with the ejecta catching sunlight high above the surface—similar to how plumes from rocket launches shortly after sunset produce “jellyfish” phenomena seen by viewers on Earth. “We have a plume search campaign throughout the tour at Jupiter,” says Turtle.
Along with producing a global and subsurface view of Europa, there are areas of particular interest. These include young, so-called chaos terrain regions of Europa, which may be signals of a churning interior, and dark irregular features known as macula.
“I think it is going to be just hugely informative and give us a spectacular, multidimensional, excellent picture of Europa and how it works,” says Turtle.
The focus is on habitability, in part because searching for life is not a task even easily defined. Given that the icy moon’s ocean is somewhat insulated from the outside, there is the possibility it could have fostered a possible second genesis within the solar system.
At the same time, If researchers are lucky, SUDA or MASPEX could detect life-like signatures. These could tease out amino and fatty acid patterns characteristic for organic matter. “I’m not saying that we hope to observe bacteria, but if there were one in such a particle, we could know it,” says Kempf, SUDA’s principal investigator. Such a detection would be nothing less than historic and set the stage for a followup lander mission.
Europa Clipper is scheduled to reach the Jupiter system in April 2030, via flybys of Mars and Earth. Then it will begin a whole new chapter in the search for life elsewhere in the solar system, illuminating the intrigues of Europa, but also providing a platform for understanding other icy moons such as Enceladus, Ganymede, and Triton.
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