Kent, Wash.-based Stoke Space successfully completed the first hot-fire test of its reusable Nova launch vehicle's first-stage engine, which reached 350,000 hp in under a second during a two-second test on June 5. GeekWire reports: During the two-second test, the engine ramped up to its target starting power level, producing the equivalent of 350,000 hp in less than a second, and held that power level until shutdown. At full power, the full-flow staged combustion engine is designed to produce over 100,000 pounds of thrust. The rocket engine was designed and manufactured in just 18 months. The medium-lift Nova rocket's first-stage booster will be powered by seven of the engines.

Stoke successfully conducted a vertical-takeoff-and-landing test flight of its reusable second stage last September. Since then, the company has been focusing on first-stage development. For the rest of this year, Stoke expects to continue maturing its engine and vehicle design while scaling operations for orbital launch. Stoke Space said last year that it was targeting 2025 for its first orbital test flight -- but that timetable depends on progress in the development program.

schwit1 shares a report: Bill Gates and his energy company are starting construction at their Wyoming site for a next-generation nuclear power plant he believes will "revolutionize" how power is generated. Gates was in the tiny community of Kemmerer Monday to break ground on the project. The co-founder of Microsoft is chairman of TerraPower. The company applied to the Nuclear Regulatory Commission in March for a construction permit for an advanced nuclear reactor that uses sodium, not water, for cooling. If approved, it would operate as a commercial nuclear power plant.

The site is adjacent to PacifiCorp's Naughton Power Plant, which will stop burning coal in 2026 and natural gas a decade later, the utility said. Nuclear reactors operate without emitting planet-warming greenhouse gases. PacifiCorp plans to get carbon-free power from the reactor and says it is weighing how much nuclear to include in its long-range planning. The work begun Monday is aimed at having the site ready so TerraPower can build the reactor as quickly as possible if its permit is approved. Russia is at the forefront for developing sodium-cooled reactors.

The dream of perpetual, emissionless flight is getting closer to reality. Aviation giants, telecoms, investors, and military agencies are pouring millions into developing these prototypes, which could revolutionize aerial surveillance, emergency communications, and more.

Solar planes absorb energy via panels covering their wings and bodies, allowing them to fly indefinitely as long as the sun shines. Advances in battery technology now enable longer flights and overnight operation, albeit with less power than jet fuel. These slow, lightweight aircraft can fly at altitudes and durations impossible for humans, making them ideal for monitoring, telecom, and disaster response. Companies like BAE Systems, Airbus, and Skydweller are racing to commercialize solar planes, with hopes of offering services by 2026-2027. The unregulated stratosphere is a key focus, with planes acting as "steerable satellites." WSJ adds: Most of the companies trying to commercialize solar planes are building aircraft that are lightweight, autonomous and can fly at altitudes and for lengths of time that humans can't tolerate. Unlike balloons, solar planes are steerable, a big advantage for monitoring a target on the ground or providing telecom coverage without being blown off course. They are also cheaper and closer to Earth than satellites, putting them in a sweet spot for services that can't currently be offered by either, executives in charge of solar-aircraft projects say. The planes can capture higher resolution photos or video than satellites, or deliver broadband internet from the air, another thing satellites can't do.

Abstract of a paper published on Nature: Personal names are a universal feature of human language, yet few analogues exist in other species. While dolphins and parrots address conspecifics by imitating the calls of the addressee, human names are not imitations of the sounds typically made by the named individual. Labelling objects or individuals without relying on imitation of the sounds made by the referent radically expands the expressive power of language. Thus, if non-imitative name analogues were found in other species, this could have important implications for our understanding of language evolution. Here we present evidence that wild African elephants address one another with individually specific calls, probably without relying on imitation of the receiver. We used machine learning to demonstrate that the receiver of a call could be predicted from the call's acoustic structure, regardless of how similar the call was to the receiver's vocalizations. Moreover, elephants differentially responded to playbacks of calls originally addressed to them relative to calls addressed to a different individual. Our findings offer evidence for individual addressing of conspecifics in elephants. They further suggest that, unlike other non-human animals, elephants probably do not rely on imitation of the receiver's calls to address one another.

An anonymous reader quotes a report from the New York Times: A committee of independent advisers to the Food and Drug Administration voted unanimously on Monday that the benefits outweigh the risks of the newest experimental drug for Alzheimer's disease. Alzheimer's afflicts more than six million Americans. It has no cure, and there is no treatment or lifestyle modification that can restore memory loss or reverse cognitive decline. The drug, made by Eli Lilly, is donanemab. It modestly slowed cognitive decline in patients in the early stages of the disease but also had significant safety risks, including swelling and bleeding in the brain. The committee concluded, though, that the consequences of Alzheimer's are so dire that even a modest benefit can be worthwhile.

The F.D.A. usually follows the advice of the agency's advisory committees but not always. The drug is based on a long-held hypothesis that Alzheimer's disease begins when rough hard balls of amyloid, a protein, pile up in patients' brains, followed by a cascade of reactions leading to the death of neurons. The idea is to treat Alzheimer's by attacking amyloid, clearing it from the brain. Two similar amyloid-fighting drugs were approved recently: Leqembi, made by Eisai and Biogen, was approved last year. That drug's risks and modest benefits are similar to those of donanemab. Aduhelm, made by Biogen, is the other drug and was approved in 2021 but was discontinued because there was insufficient evidence that it could benefit patients. Donanemab was expected to be approved earlier this year, but in March, the F.D.A. decided that, instead, it would require donanemabto undergo the scrutiny of an independent advisory committee, a surprise to Eli Lilly.

The vote, said Dr. Daniel Skovronsky, chief scientific officer at Lilly, confirmed his 25-year quest to find a way to intervene in the Alzheimer's disease. Now, he said, the company is starting a study that, it hopes, will stop the disease before symptoms even begin. At issue before the committee on Monday were some unusual aspects of donanemab's clinical trials, especially that study participants stopped taking the drug as soon as their amyloid was cleared. Some experts questioned whether stopping was the best strategy and whether clinical practice should include halting the treatment after amyloid clearance.

Scientists have discovered early morning frost on the summits of Martian volcanoes near the planet's equator, indicating that water ice forms overnight in colder months and evaporates after sunrise. "While the frosty layer is exceptionally thin, it covers an enormous area," reports The Guardian. "Scientists calculate that in the more frigid Martian seasons, 150,000 tons of water, equivalent to 60 Olympic swimming pools, condense daily on the tops of the towering mountains." From the report: "It's the first time we've discovered water frost on the volcano summits and the first time we've discovered water frost in the equatorial regions of Mars," said Adomas Valantinas, a planetary scientist at the University of Berne in Switzerland and Brown University in the US. "What we're seeing could be a trace of a past Martian climate," Valantinas said of the frost-tipped volcanoes. "It could be related to atmospheric climate processes that were operating earlier in Martian history, maybe millions of years ago."

Valantinas spotted the frost-capped volcanoes in high-resolution colour images snapped in the early morning hours on Mars by the European Space Agency's Trace Gas Orbiter (TGO). With colleagues, he confirmed the discovery using a spectrometer on TGO and further images taken by the agency's Mars Express orbiter. The frost appears as a bluish hue on the caldera floors and is absent from well-lit slopes. [...] [W]riting in Nature Geoscience, the researchers describe how Martian winds may blow up the mountainsides and carry more moist air into the calderas where it condenses and settles as frost at particular times of year. Modeling of the process suggests the frost is water ice as the peaks are not cold enough for carbon dioxide frost to form.

Jay Peters reports via The Verge: The iPad is finally getting a Calculator app as part of iPadOS 18. The long-requested app was just announced by Apple at WWDC 2024. On its face, the app looks a lot like the calculator you might be familiar with from iOS. But it also supports Apple Pencil, meaning that you can write down math problems and the app will solve them thanks to a feature Apple calls Math Notes. Other features included in iPadOS 18 include a new, customizable floating tab bar; enhanced SharePlay functionality for easier screen sharing and remote control of another person's iPad; and Smart Script, a handwriting feature that refines and improves legibility using machine learning.

Microplastic pollution has been found in all human semen samples tested in a study, and researchers say further research on the potential harm to reproduction is "imperative." From a report: Sperm counts in men have been falling for decades and 40% of low counts remain unexplained, although chemical pollution has been implicated by many studies. The 40 semen samples were from healthy men undergoing premarital health assessments in Jinan, China. Another recent study found microplastics in the semen of six out of 10 healthy young men in Italy, and another study in China found the pollutants in half of 25 samples.

Recent studies in mice have reported that microplastics reduced sperm count and caused abnormalities and hormone disruption. Research on microplastics and human health is moving quickly and scientists appear to be finding the contaminants everywhere. The pollutants were found in all 23 human testicle samples tested in a study published in May. Microplastics have also recently been discovered in human blood, placentas and breast milk, indicating widespread contamination of people's bodies. The impact on health is as yet unknown but microplastics have been shown to cause damage to human cells in the laboratory.

SpaceX's successful launch (and reentry) of Starship was just the beginning, reports Space.com: SpaceX now aims to build on the progress with its Starship program as continues work on Starfactory, a new manufacturing facility under construction at the company's Starbase site in South Texas... "When you step into this factory, it is truly inspirational. My heart jumps out of my chest," Kate Tice, manager of SpaceX Quality Systems Engineering, said [during SpaceX's livestream of the Starship flight test]. "Now this will enable us to increase our production rate significantly as we build toward our long-term goal of producing one Ship per day and coming off the production line soon, Starship Version Two."

This new version of Starship is designed to be more easy to mass produce, SpaceX CEO Elon Musk said on social media.
Space.com argues that the long-term expansion comes as SpaceX "looks to use Starship to eventually make humanity interplanetary."

"Virgin Galactic launched six people to suborbital space on Saturday, launching a Turkish astronaut and three space tourists," reports Space.com, "on what was the final voyage of the VSS Unity space plane." Unity, attached to the belly of its carrier plane Eve, took off from runway at Spaceport America in New Mexico at 10:31 a.m. EDT (1431 GMT) and carried to an altitude of 44,562 feet (13,582 meters) over the next hour, where it was dropped and ignited its rocket engine to carry two pilots and four passengers to space and back. The mission, called Galactic 07, reached an altitude of 54.4 miles (87.5 km) and marked the seventh commercial spaceflight by Virgin Galactic on Unity, which is being retired to make way for the company's new "Delta" class of spacecraft rolling out in 2026.

"I will need much more time to try and process what just happened," Tuva Atasever, the Turkish Space Agency astronaut on the flight, said in a post-flight press conference, adding that the view of Earth was indescribable. "It's not something you can describe with adjectives. It's an experiential thing ... you just feel it in your gut."
One of the space tourists was a principal propulsion engineer at SpaceX, who wore the flags of the U.S. and India on his spacesuit to honor both his home country and that of his parents. The other two were a New York-based real estate developer and a London-based hotel and resort investment strategy advisor.

The flight landed 70 minutes later at 11:41 a.m. EDT (1541 GMT), according to the article, "marking only its seventh commercial spaceflight for Virgin Galactic and 12th crewed spaceflight overall." In all, Virgin Galactic flew the space plane just 32 times, including non-space test flights... "This vehicle was revolutionary," Virgin Galactic president Mike Moses said in the post-launch press conference. "We tested it, we flew it, we demonstrated and prove to the world that commercial human spaceflight is possible with private funding for private companies... Seven commercial space flights, a single vehicle flying six times in six months last year, that's groundbreaking," Moses said. "The fact that we can take this vehicle back to back to back on a monthly basis is is really revolutionary."

The new Delta class of spacecraft will be able to fly at least twice a week, about eight times the rate of SpaceShipTwo, with Virgin Galactic planning to build at least two to start its new fleet. "We're going to field in 2026 two spaceships, our mothership Eve, that's 750 astronauts a year going to space," Moses said of the new fleet's flight capacity. "That's more than have gotten to space in the 60 year history of spaceflight to date...."

Since 2018, Virgin Galactic has flown payloads as part of NASA's Flight Opportunities program and most recently was selected to be a contracted flight provider for NASA for the next five years.
Phys.org reports that with the Delta-class rockets, "The future of the company is at stake as it seeks at long last to get into the black. Virgin is burning through cash, losing more than $100 million in each of the past two quarters, with its reserves standing at $867 million at the end of March." It also laid off 185 people, or 18 percent of its workforce, late last year. Its shares are currently trading at 85 cents, down from $55 in 2021, the year Branson himself flew, garnering global headlines.
Saturday's flight also became "a suborbital science lab" for microgravity research, according to a statement from the company. Phys.org reports that during the flight, astronaut Atasever "wore custom headgear with brain activity monitoring sensors to collect physiological data, a dosimeter, and two commercially available insulin pens to examine the ability to administer accurate insulin doses in microgravity, Virgin said in a statement." And Virgin Galactic said their flight also carried "rack-mounted" autonomous payloads from both Purdue ("to study propellant slosh in fuel tanks of maneuvering spacecraf") and U.C. Berkeley ("testing a new type of 3D printing"), as well as "multiple human-tended experiments." "Discovery and innovation are central to our mission at Virgin Galactic," said Michael Colglazier, CEO of Virgin Galactic. "We're excited to build on our successful record of facilitating scientific experiments in suborbital space, and we look forward to continuing to expand our role in suborbital research going forward."

"The first European Space Agency instrument to land on the Moon has detected the presence of negative ions on the lunar surface produced through interactions with the solar wind," according to a statement from the agency, collecting over three hours of data, "three times more than what the science teams needed for mission success..." The solar wind is a constant flow of radiation and particles from the Sun. Earth's magnetic field acts as a shield. In contrast, the Moon has no magnetic field and a very tenuous atmosphere, called the exosphere. When the solar wind hits the Moon,âthe surface reacts, kicking up secondary particles... While the positively charged particles have been measured from orbit before, measuring negative particles was a challenge. Negative ions are short-lived and cannot make it to orbit.
The instrument was dropped off by China's Chang'e-6 lunar lander, and Europe's ground stations are also providing support for that mission. Futurism reports: Within just over 48 hours, China's Chang'e-6 lunar touched down on the far side of the Moon, successfully scooped up samples, and kicked off once again. It was an extraordinary feat, representing the first-ever samples ever collected from the side of the Moon that permanently faces away from us. During its brief visit, the lander also dropped off several scientific payloads on the lunar service, including the European Space Agency's Negative Ions at the Lunar Surface instrument.
The lander also unfurled China's red and gold flag for the first time on the far side of the moon, according to the Associated Press. And then... Its ascender lifted off Tuesday morning at 7:38 a.m. Beijing time, with its engine burning for about six minutes as it entered a preset orbit around the moon, the China National Space Administration said. The agency said the spacecraft withstood a high temperature test on the lunar surface, and acquired the samples using both drilling and surface collection before stowing them in a container inside the ascender of the probe as planned. The container will be transferred to a reentry capsule that is due to return to Earth in the deserts of China's Inner Mongolia region about June 25.
The samples "could help researchers figure out why the moon's two sides are so starkly different," writes Science News: Spacecraft observations of the farside show very little volcanic activity. Some scientists suspect that this is because the nearside crust is much thinner, which would have allowed more magma to come up from below the surface, says Kerri Donaldson Hanna, a planetary geologist at the University of Central Florida in Orlando.

There is evidence that some volcanism occurred in the South Pole-Aitken basin and in Apollo crater, though it appears this activity happened roughly 3.5 billion years ago. It's possible the impact that created both Aiken and Apollo weakened the lunar crust, forming fractures and allowing magma to flow. The samples onboard Chang'e-6 could contain clues as to whether or not this happened.

Both Chinese and international researchers will be able to study the material. Donaldson Hanna is looking forward to seeing what insights will be gleaned from Chang'e-6 as well as future landers, such as those in NASA's Commercial Lunar Payload Services program.
Thanks to Slashdot reader cusco for sharing the news.

CNN reports that the low-calorie sweetener xylitol used "may be linked to nearly twice the risk of heart attacks, stroke and death in people who consume the highest levels of the sweetener, a new study found..." In 2023, the same researchers found similar results for another low-calorie sweetener called erythritol, which is used as a bulking sugar in stevia, monkfruit and keto reduced-sugar products. Additional lab and animal research presented in both papers revealed erythritol and xylitol may cause blood platelets to clot more readily. Clots can break off and travel to the heart, triggering a heart attack, or to the brain, triggering a stroke.

In the new study on xylitol, "differences in platelet behavior were seen even after a person consumed a modest quantity of xylitol in a drink typical of a portion consumed in real life," said Dr. Matthew Tomey, a cardiologist at Mount Sinai Fuster Heart Hospital in New York City, who was not involved in the study... "Through their work, the investigators have shined a light on the safety of sugar substitutes. There is more to learn," Mount Sinai's Tomey said. "In the meantime, it is worth remembering that sugar substitutes are no substitute for a sincere commitment to the several elements of a healthy diet and lifestyle."
Tomey added that the experiments "are interesting but alone do not prove that platelet abnormalities are to account for a linkage between xylitol and clinical events." But CNN notes that the researchers began by analyzing over 3,200 blood samples — and then also gave volunteers a typical xylitol-sweetened drink to see how much in increased their glucose levels. "They went up 1,000-fold," senior study author Dr. Stanley Hazen told CNN.

His study adds that the World Health Organization warned consumers in 2023 to avoid artificial sweeteners for weight loss and called for additional research on the long-term toxicity of low- and no-calorie sweeteners.

An anonymous reader quotes a report from Science Magazine: Authors of a landmark Alzheimer's disease research paper published in Nature in 2006 have agreed to retract the study in response to allegations of image manipulation. University of Minnesota (UMN) Twin Cities neuroscientist Karen Ashe, the paper's senior author, acknowledged in a post on the journal discussion site PubPeer that the paper contains doctored images. The study has been cited nearly 2500 times, and would be the most cited paper ever to be retracted, according to Retraction Watch data. "Although I had no knowledge of any image manipulations in the published paper until it was brought to my attention two years ago," Ashe wrote on PubPeer, "it is clear that several of the figures in Lesne et al. (2006) have been manipulated ... for which I as the senior and corresponding author take ultimate responsibility." After initially arguing the paper's problems could be addressed with a correction, Ashe said in another post last week that all of the authors had agreed to a retraction -- with the exception of its first author, UMN neuro-scientist Sylvain Lesne, a protege of Ashe's who was the focus of a 2022 investigation by Science. "It's unfortunate that it has taken 2 years to make the decision to retract," says Donna Wilcock, an Indiana University neuroscientist and editor of the journal Alzheimer's & Dementia. "The evidence of manipulation was overwhelming."

The 2006 paper suggested an amyloid beta (AB) protein called AB*56 could cause Alzheimer's. AB proteins have long been linked to the disease. The authors reported that AB*56 was present in mice genetically engineered to develop an Alzheimer's-like condition, and that it built up in step with their cognitive decline. The team also reported memory deficits in rats injected with AB*56. For years researchers had tried to improve Alzheimer's outcomes by stripping amyloid proteins from the brain, but the experimental drugs all failed. AB*56 seemed to offer a more specific and promising therapeutic target, and many embraced the finding. Funding for related work rose sharply. But the Science investigation revealed evidence that the Nature paper and numerous others co-authored by Lesne, some listing Ashe as senior author, appeared to use manipulated data. After the story was published, leading scientists who had cited the paper to support their own experiments questioned whether AB*56 could be reliably detected and purified as described by Lesne and Ashe -- or even existed. Some said the problems in that paper and others supported fresh doubts about the dominant hypothesis that amyloid drives Alzheimer's. Others maintained that the hypothesis remains viable. That debate has continued amid the approval of the antiamyloid drug Leqembi, which modestly slows cognitive decline but carries risks of serious or even fatal brain swelling or bleeding.

An anonymous reader quotes a report from New Atlas: The universe is awash with strange radio signals, but astronomers have now detected a really bizarre one that repeats every hour, cycling through three different states. While they have some ideas about its origin it can't be explained by our current understanding of physics. The signal first appeared in data gathered by the ASKAP radio telescope in Australia, which watches a big swath of sky at once for transient pulses. Officially designated ASKAP J1935+2148, the signal seems to repeat every 53.8 minutes. Whatever it is, the signal cycles through three different states. Sometimes it shoots out bright flashes that last between 10 and 50 seconds and have a linear polarization, meaning the radio waves all "point" in the same direction. Other times, its pulses are much weaker with a circular polarization, lasting just 370 milliseconds. And sometimes, the object misses its cue and stays silent.

So what could be behind such a weird radio signal? Let's get it out of the way up front: it's not aliens (probably). The most likely explanation, according to the scientists who discovered it, is that it's coming from a neutron star or a white dwarf. But it's not a neat solution, since the signal's weird properties don't fit with our understanding of the physics of those two kinds of objects. Neutron stars and white dwarfs are fairly similar, but with some key differences. They're both born from the deaths of bigger stars, with the original mass dictating whether you end up with a neutron star or a white dwarf. Neutron stars are known to blast radio waves out regularly, so they're a prime suspect here. It's possible that signals this varied could be produced by interactions between their strong magnetic fields and complex plasma flows. But there's a major problem: they usually spin at speeds of seconds or fractions of a second per revolution. It should be physically impossible for one to spin as slow as once every 54 minutes. White dwarfs, on the other hand, would have no problem spinning that slowly, but as the team says, "we don't know of any way one could produce the radio signals we are seeing here." "It might even prompt us to reconsider our decades-old understanding of neutron stars or white dwarfs; how they emit radio waves and what their populations are like in our Milky Way galaxy," added Caleb.

The findings have been published in the journal Nature Astronomy.

Longtime Slashdot reader destinyland shared a story from Space.com reporting on Boeing's missed opportunity to dock with the International Space Station, after five of the 28 thrusters that help control Starliner's movement in space stopped operating. NASA has since been able to recover four of the thrusters to successfully dock Boeing's Starliner capsule with the ISS. From the report: There are now two U.S.-built crew spacecraft docked with the ISS for the first time. Boeing's Starliner joined SpaceX's Dragon capsule "Endeavour," which arrived in March. Boeing's Starliner launched successfully on Wednesday to begin the crew flight test. The mission represents a final major step before NASA certifies Boeing to fly crew on operational missions. [...]

NASA flight controllers called off a previously scheduled approach to resolve issues with Starliner's propulsion system. Starliner has 28 jets, known as its reaction control system, or RCS, engines, that help the spacecraft make small movements in orbit. The crew on Starliner, NASA astronauts Butch Wilmore and Suni Williams, were told by NASA capsule communicator, or CAPCOM, Neal Nagata, that the 12:15 p.m. docking attempt had to be called off to resolve the spacecraft's propulsion issue. CAPCOM Nagata noted that the ISS has a zero fault tolerance for a spacecraft control problem.

The agency and Boeing had to troubleshoot five of the RCS jets that were not operating. Four of Starliner's malfunctioning jets were recovered after Wilmore and Williams worked with flight controllers to test fire the thrusters. CAPCOM Nagata had the astronauts hold the spacecraft beyond the "keep out sphere," an invisible boundary around the ISS that serves as a safety measure, while diagnosing the problematic thrusters.