Science

there-are-2,000-plus-dead-rockets-in-orbit—here’s-a-rare-view-of-one

There are 2,000-plus dead rockets in orbit—here’s a rare view of one

Astroscale, Commercial space, h-iia, Japan, JAXA, launch, Science, Space, space debris / /
Astroscale's ADRAS-J spacecraft captured these views of the H-IIA rocket upper stage on July 15.

Enlarge / Astroscale’s ADRAS-J spacecraft captured these views of the H-IIA rocket upper stage on July 15.

There are more than 2,000 mostly intact dead rockets circling the Earth, but until this year, no one ever launched a satellite to go see what one looked like after many years of tumbling around the planet.

In February, a Japanese company named Astroscale sent a small satellite into low-Earth orbit on top of a Rocket Lab launcher. A couple of months later, Astroscale’s ADRAS-J (Active Debris Removal by Astroscale-Japan) spacecraft completed its pursuit of a Japanese rocket stuck in orbit for more than 15 years.

ADRAS-J photographed the upper stage of an H-IIA rocket from a range of several hundred meters and then backed away. This was the first publicly released image of space debris captured from another spacecraft using rendezvous and proximity operations.

Since then, Astroscale has pulled off more complex maneuvers around the H-IIA upper stage, which hasn’t been controlled since it deployed a Japanese climate research satellite in January 2009. Astroscale attempted to complete a 360-degree fly-around of the H-IIA rocket last month, but the spacecraft triggered an autonomous abort one-third through the maneuver after detecting an attitude anomaly.

ADRAS-J flew away from the H-IIA rocket for several weeks. After engineers determined the cause of the glitch that triggered the abort, ADRAS-J fired thrusters to approach the upper stage again this month. The ADRAS-J spacecraft is about the size of a kitchen oven, while the H-IIA rocket it’s visiting is nearly the size of a city bus.

Astroscale’s satellite completed two fly-around maneuvers of the H-IIA upper stage on July 15 and 16, examining all sides of the rocket as it soared more than 350 miles (560 kilometers) above the planet. Engineers also wanted to measure the upper stage’s spin rate and spin axis. At first glance, the upper stage appears remarkably similar to the way it looked when it launched. Despite exposure to the harsh conditions of space, the rocket’s outer skin remains covered in orange foam insulation, and the engine nozzle still shines as if it were new.

ADRAS-J autonomously maneuvered around the rocket at a distance of about 50 meters (164 feet), using navigation data from a light detection and ranging sensor and Astroscale’s custom-developed guidance algorithms to control its position as the vehicles moved around Earth at nearly 4.7 miles per second (7.6 kilometers per second). This is the crux of the challenge for ADRAS-J because the rocket is unpowered and unable to hold position. The upper stage also lacks laser reflectors and targets that would aid an approaching spacecraft.

This is a first

These types of complex maneuvers, known as rendezvous and proximity operations (RPO), are common for crew and cargo spacecraft around the International Space Station. Other commercial satellites have demonstrated formation-flying and even docking with a spacecraft that wasn’t designed to connect with another vehicle in orbit.

Military satellites from the United States, Russia, and China also have RPO capabilities, but as far as we know, these spacecraft have only maneuvered in ultra-close range around so-called “cooperative” objects designed to receive them. In 2003, the Air Force Research Laboratory launched a small satellite named XSS-10 to inspect the upper stage of a Delta II rocket in orbit, but it had a head start. XSS-10 maneuvered around the same rocket that deployed it, rather than pursuing a separate target.

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Silicon plus perovskite solar reaches 34 percent efficiency

green, green energy, materials science, perovskites, photovoltaics, Science, solar power, Sustainability / /
Solar panels with green foliage behind them, and a diagram of a chemical's structure in the foreground.

Enlarge / Some solar panels, along with a diagram of a perovskite’s crystal structure.

As the price of silicon panels has continued to come down, we’ve reached the point where they’re a small and shrinking cost of building a solar farm. That means that it might be worth spending more to get a panel that converts more of the incoming sunlight to electricity, since it allows you to get more out of the price paid to get each panel installed. But silicon panels are already pushing up against physical limits on efficiency. Which means our best chance for a major boost in panel efficiency may be to combine silicon with an additional photovoltaic material.

Right now, most of the focus is on pairing silicon with a class of materials called perovskites. Perovskite crystals can be layered on top of silicon, creating a panel with two materials that absorb different areas of the spectrum—plus, perovskites can be made from relatively cheap raw materials. Unfortunately, it has been difficult to make perovskites that are both high-efficiency and last for the decades that the silicon portion will.

Lots of labs are attempting to change that, though. And two of them reported some progress this week, including a perovskite/silicon system that achieved 34 percent efficiency.

Boosting perovskite stability

Perovskites are an entire class of materials that all form the same crystal structure. So, there is plenty of flexibility when it comes to the raw materials being used. Perovskite-based photovoltaics are typically formed by what’s called solution processing, in which all the raw materials are dissolved in a liquid that’s then layered on top of the panel-to-be, allowing perovskite crystals to form across its entire surface. Which is great, except that this process tends to form multiple crystals with different orientations on a single surface, decreasing performance.

Adding to the problems, perovskites are also not especially stable. They’re usually made of a combination of positively and negatively charged ions, and these have to be present in the right ratios to form a perovskite. However, some of these individual ions can diffuse over time, disrupting the crystal structure. Harvesting solar energy, which involves the material absorbing lots of energy, makes matters worse by heating the material, which increases the rate of diffusion.

Combined, these factors sap the efficiency of perovskite solar cells and mean that none lasts nearly as long as a sheet of silicon. The new works tackle these issues from two very different directions.

The first of the new papers tackles stability by using the flexibility of perovskites to incorporate various ions. The researchers started by using a technique called density functional theory to model how different molecules would behave when placed into a spot normally occupied by a positively charged ion. And the modeling got them excited about a molecule called tetrahydrotriazinium, which has a six-atom ring composed of alternating carbon and nitrogen atoms. The regular placement of nitrogens around the ring allows it to form regular interactions with neighboring atoms in the crystal structure.

Tetrahydrotriazinium has a neutral charge when only two of the nitrogens have hydrogens attached to them. But it typically grabs a charged hydrogen (effectively, a proton) out of solution, giving it a net positive charge. This leaves each of its three nitrogens associated with a hydrogen and allows the positive charge to be distributed among them. That makes this interaction incredibly strong, meaning that the hydrogens are extremely unlikely to drift off, which also stabilizes the crystal structure.

So, this should make perovskites much, much more stable. The only problem? Tetrahydrotriazinium tends to react with lots of other chemicals, so it’s difficult to provide as a raw material for the perovskite-forming solution.

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Human muscle cells come back from space, look aged

Biology, gene activity, muscle cells, Science, Space, Space exploration / /

Putting some muscle into it —

Astronauts’ muscles atrophy in space, but we can identify the genes involved.

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Image of two astronauts in an equipment filled chamber, standing near the suits they wear for extravehicular activities.

Enlarge / Muscle atrophy is a known hazard of spending time on the International Space Station.

Muscle-on-chip systems are three-dimensional human muscle cell bundles cultured on collagen scaffolds. A Stanford University research team sent some of these systems to the International Space Station to study the muscle atrophy commonly observed in astronauts.

It turns out that space triggers processes in human muscles that eerily resemble something we know very well: getting old. “We learned that microgravity mimics some of the qualities of accelerated aging,” said Ngan F. Huang, an associate professor at Stanford who led the study.

Space-borne bioconstructs

“This work originates from our lab’s expertise in regenerative medicine and tissue engineering. We received funding to do a tissue engineering experiment on the ISS, which really helped us embark on this journey, and became curious how microgravity affects human health,” said Huang. So her team got busy designing the research equipment needed to work onboard the space station. The first step was building the muscle-on-chip systems.

“A lot of what was known about how space affects muscles was gathered through studying the astronauts or studying animals like mice put in microgravity for research purposes,” Huang said. “In some cases, there were also in vitro cultured cells on a Petri dish—something very basic. We wanted to have something more structurally complex.” Her team developed a muscle-on-chip platform in which human myotubes, cells that organize into long parallel bundles that eventually become muscle fibers in a living organism, were grown on collagen scaffolds. The goal was to make the samples emulate real muscles better. But that came with a challenge: keeping them alive on the ISS.

“When we grow cells on Earth, we pour the medium—basically a liquid with nutrients that allow the cells to grow—over the cells, and everything is fine,” Huang said. “But in space, in the absence of gravity, we needed a closed, leak-proof, tightly sealed chamber. The medium was sloshed around in there.”

Oxygen and carbon dioxide levels were maintained with permeable membranes. Changing the medium was a complicated procedure involving syringes and small custom-designed ports. But getting all this gadgetry up and running was worth it in the end.

Genes of atrophy

Huang’s team had two sets of muscle-on-chip systems: one on the ground and one on the ISS. The idea of the study was to compare the genes that were upregulated or downregulated in each sample set. It turned out that many genes associated with aging saw their activity increase in microgravity conditions.

This result was confirmed when the team analyzed the medium that was taken off after the cells had grown in it. “The goal was to identify proteins released by the cells that were associated with microgravity. Among those, the most notable was the GDF15, which is relevant to different diseases, particularly mitochondrial dysfunction or senescence,” said Huang.

Overall, the condition of cells on the ISS was somewhat similar to sarcopenia, an age-related muscle loss disease. “There were some similarities, but also a lot of differences. The reason we didn’t make sarcopenia the main focus of this study is that we know our muscle-on-chip system is a model. It’s mostly muscle cells on a scaffold. It doesn’t have blood vessels or nerves. Comparing that to clinical, real muscle samples is a bit tricky, as it is not comparing apples to apples,” said Huang.

Nevertheless, her team went on to use their ISS muscle-on-chip samples to conduct proof-of-concept drug screening tests. Drugs they tested included those used to treat sarcopenia, among other conditions.

Space drugs

“One of the drugs we tested was the [protein] IGF 1, which is a growth factor naturally found in the body in different tissues, especially in muscles. When there is an injury, IGF 1 activates within a body to initiate muscle regeneration. Also, IGF 1 tend to be declined in aging muscles,” said Huang. The second drug tested was 15-PGDH-i, a relatively new inhibitor of enzymes that hinder the process of muscle regeneration. Used on the muscles-on-chip on the ISS, the drugs partially reduced some of the microgravity-related effects.

“One of the limitations of this work was that on the ISS, the microgravity is also accompanied by other factors, such as ionizing radiation, and it is hard to dissociate one from the other,” said Huang. It’s still unclear if the effects observed in the ISS samples were there due to radiation, the lack of gravity, both, or some additional factor. Huang’s team plans to do similar experiments on Earth in simulated microgravity conditions. “With some of the specialized equipment we recently acquired, it is possible to look at just the effects of microgravity,” Huang said. Those experiments are aimed at testing a wider range of drugs.

“The reason we do this drug screening is to develop drugs that could either be taken preemptively or during the flight to counteract muscle atrophy. It would probably be more feasible, lighter, and cheaper than doing artificial gravity concepts,” Huang said. The most promising candidate drugs selected in these ground experiments will be tested on Huang’s muscle-on-chip systems onboard the ISS in 2025.

Stem Cell Reports, 2024. DOI: 10.1016/j.stemcr.2024.06.010

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nasa’s-lunar-gateway-has-a-big-visiting-vehicles-problem

NASA’s Lunar Gateway has a big visiting vehicles problem

lunar gateway, NASA, Science, Space / /

Stack controllability —

“These defects could lead the flight computers to unexpectedly restart.”

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A rendering of NASA's proposed lunar gateway.

Enlarge / A rendering of NASA’s proposed lunar gateway.

NASA

Do you remember the Lunar Gateway? You could be forgiven if not, as the program continues to be tossed around by NASA planners, and it is still not entirely clear what purpose the lunar space station is supposed to serve.

The Gateway—a small space station that will fly in a halo orbit around the Moon and spend most of its time far from the lunar surface—was initially supposed to launch in 2022. That obviously did not happen, and now, according to a new report from the US Government Accountability Office, the space agency does not expect the launch of the initial elements of the Gateway until at least December 2027. The baseline cost estimate is $5.3 billion.

NASA’s present plans contemplate using the Gateway as part of the Artemis IV mission, presently scheduled for September 2028. Unfortunately, the Gateway’s current launch target is already three months later than needed to support Artemis IV, the second mission to land humans on the Moon. But that’s OK. There are a lot of other moving parts for this mission, so a launch any time this decade would be a win.

The report includes a helpful cartoon to explain the complicated sequence that needs to happen for Gateway to be involved in the Artemis IV mission:

  • Launch of the initial segments of the Gateway, a power and propulsion module, and a habitation module, to a halo orbit around the Moon
  • Launch of a SpaceX Dragon XL vehicle to bring supplies to the Gateway
  • Launch of multiple SpaceX Starships to fuel a Lunar Starship, which will then fly to and dock with the Gateway
  • Launch of a NASA Space Launch System rocket carrying four astronauts inside an Orion spacecraft as well as another Gateway module
  • After launch, Orion separates from the rocket and docks with this module, the International Habitat
  • Orion tugs the International Habitat to the Gateway and docks; the crew exits onto Gateway
  • Two crew members board the Lunar Starship and go down to the Moon for six days
  • Starship flies back to the Gateway, and the four astronauts return to Earth inside Orion.
How the Artemis IV mission will (probably) take place.

How the Artemis IV mission will (probably) take place.

US GAO

In a rather understated manner, the report notes that this plan is fairly complex and faces some serious schedule risks.

“This mission will be complex because NASA will need to coordinate across seven NASA programs, multiple contractors that support those programs, and international partners to execute the mission,” the report states. “It will also be the first launch of an upgraded version of the Space Launch System rocket.”

Developmental difficulties

The report also finds that the Gateway program is running into some pretty serious technical difficulties. One involves a defective network chip that facilitates communication throughout the lunar space station. Its failure could cause myriad problems onboard the Gateway.

“For example, these defects could lead the flight computers to unexpectedly restart,” the report states. “If the network is not functioning properly, it could result in loss of control of the Gateway. Program officials are also concerned that they might identify more defects with the communication network, based on the number found already.”

Another risk involves something called “stack controllability.” This essentially means that because SpaceX’s Lunar Starship is so much more massive than the Gateway, when it is docked to the space station, the Gateway’s power and propulsion element (PPE) will not be able to maintain a proper orientation of the entire stack.

“Program officials estimate that the mass of the lunar lander Starship is approximately 18 times greater than the value NASA used to develop the PPE’s controllability parameters,” the report states. “According to NASA’s system engineering guidance, late requirements and design changes can lead to cost growth and schedule delays.”

The report also has some sobering conclusions about the potential utility of the Lunar Gateway for Mars missions. (In the past, NASA officials have spoken about the Gateway as a staging area for spacecraft and propellant for human missions to the surface of Mars.) However, the “stack controllability” issue poses a serious constraint to hosting large Mars transit vehicles. Moreover, the planned 15-year lifetime of the Gateway may not be long enough to sustain Mars missions.

“The Gateway could have exceeded its planned 15-year on-orbit life as early as 2042 when crewed missions to Mars are potentially just beginning,” the report states.

All in all, the report seems to suggest that the Gateway is way behind schedule and is of limited use to lunar and Mars landings. The report suggests the Gateway will be complex to undertake at the very same time NASA is attempting to establish a lunar surface program. But other than that, everything is going great.

NASA’s Lunar Gateway has a big visiting vehicles problem Read More »

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Karaoke reveals why we blush

Biology, embarrassment, karaoke, neurobiology, Science / /

Singing for science —

Volunteers watched their own performances as an MRI tracked brain activity.

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A hand holding a microphone against a blurry backdrop, taken from an angle that implies the microphone is directly in front of your face.

Singing off-key in front of others is one way to get embarrassed. Regardless of how you get there, why does embarrassment almost inevitably come with burning cheeks that turn an obvious shade of red (which is possibly even more embarrassing)?

Blushing starts not in the face but in the brain, though exactly where has been debated. Previous thinking often reasoned that the blush reaction was associated with higher socio-cognitive processes, such as thinking of how one is perceived by others.

After studying subjects who watched videos of themselves singing karaoke, however, researchers led by Milica Nicolic of the University of Amsterdam have found that blushing is really the result of specific emotions being aroused.

Nicolic’s findings suggest that blushing “is a consequence of a high level of ambivalent emotional arousal that occurs when a person feels threatened and wants to flee but, at the same time, feels the urge not to give up,” as she and her colleagues put it in a study recently published in Proceedings of the Royal Society B.

Taking the stage

The researchers sought out test subjects who were most likely to blush when watching themselves sing bad karaoke: adolescent girls. Adolescents tend to be much more self-aware and more sensitive to being judged by others than adults are.

The subjects couldn’t pick just any song. Nicolic and her team had made sure to give them a choice of four songs that music experts had deemed difficult, which is why they selected “Hello” by Adele, “Let it Go” from Frozen, “All I Want For Christmas is You” by Mariah Carey, and “All the Things You Said” by tATu. Videos of the subjects were recorded as they sang.

On their second visit to the lab, subjects were put in an MRI scanner and were shown videos of themselves and others singing karaoke. They watched 15 video clips of themselves singing and, as a control, 15 segments of someone who was thought to have similar singing ability, so secondhand embarrassment could be ruled out.

The other control factor was videos of professional singers disguised as participants. Because the professionals sang better overall, it was unlikely they would trigger secondhand embarrassment.

Enough to make you blush

The researchers checked for an increase in cheek temperature, as blood flow measurements had been used in past studies but are more prone to error. This was measured with a fast-response temperature transducer as the subjects watched karaoke videos.

It was only when the subjects watched themselves sing that cheek temperature went up. There was virtually no increase or decrease when watching others—meaning no secondhand embarrassment—and a slight decrease when watching a professional singer.

The MRI scans revealed which regions of the brain were activated as subjects watched videos of themselves. These include the anterior insular cortex, or anterior insula, which responds to a range of emotions, including fear, anxiety, and, of course, embarrassment. There was also the mid-cingulate cortex, which emotionally and cognitively manages pain—including embarrassment—by trying to anticipate that pain and reacting with aversion and avoidance. The dorsolateral prefrontal cortex, which helps process fear and anxiety, also lit up.

There was also more activity detected in the cerebellum, which is responsible for much of the emotional processing in the brain, when subjects watched themselves sing. Those who blushed more while watching their own video clips showed the most cerebellum activity. This could mean they were feeling stronger emotions.

What surprised the researchers was that there was no additional activation in areas known for being involved in the process of understanding one’s mental state, meaning someone’s opinion of what others might think of them may not be necessary for blushing to happen.

So blushing is really more about the surge of emotions someone feels when being faced with things that pertain to the self and not so much about worrying what other people think. That can definitely happen if you’re watching a video of your own voice cracking at the high notes in an Adele song.

Proceedings of the Royal Society B, 2024.  DOI: 10.1098/rspb.2024.0958

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Boeing’s Starliner has cost at least twice as much as SpaceX’s Crew Dragon

Boeing, commercial crew, international space station, NASA, Science, Space, starliner / /

$$$ —

“Risk remains that we may record additional losses in future periods.”

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A Starliner spacecraft departs Boeing's spacecraft processing facility before the program's first orbital test flight in 2019.

Enlarge / A Starliner spacecraft departs Boeing’s spacecraft processing facility before the program’s first orbital test flight in 2019.

Boeing announced another financial charge Wednesday for its troubled Starliner commercial crew program, bringing the company’s total losses on Starliner to $1.6 billion.

In its quarterly earnings report, Boeing registered a $125 million loss on the Starliner program, blaming delays on the spacecraft’s still-ongoing Crew Flight Test, the program’s first mission to carry astronauts into orbit. This is not the first time Boeing has reported a financial loss on Starliner. Including the new charge announced Wednesday, Boeing has now suffered an overall loss on the program of nearly $1.6 billion since 2016.

These losses have generally been caused by schedule delays and additional work to solve problems on Starliner. When NASA awarded Boeing a $4.2 billion contract to complete development of the Starliner spacecraft a decade ago, the aerospace contractor projected the capsule would be ready to fly astronauts by the end of 2017.

It turns out the Crew Flight Test didn’t launch until June 5, 2024.

In a separate announcement Wednesday, Boeing named Kelly Ortberg as the company’s CEO, effective August 8. He will replace Dave Calhoun, whose tenure as Boeing’s chief executive was marred by scandals with the 737 MAX passenger airplane. Ortberg was previously CEO of Rockwell Collins, now known as Collins Aerospace, a major supplier of avionics and other parts for the aerospace industry.

Boeing is on the hook

When NASA selected Boeing and SpaceX to develop the Starliner and Crew Dragon spacecraft for astronaut missions, the agency signed fixed-price agreements with each contractor. These fixed-price contracts mean the contractors, not the government, are responsible for paying for cost overruns.

So, with each Starliner delay since 2016, Boeing’s financial statements registered new losses. It will be Boeing’s burden to pay for solutions to problems discovered on Starliner’s ongoing crew test flight. That’s why Boeing warned investors Wednesday that it could lose more money on the Starliner program in the coming months and years.

“Risk remains that we may record additional losses in future periods,” Boeing wrote in an SEC filing.

Taking into account the financial loss revealed Wednesday, NASA and Boeing have committed at least $6.7 billion to the Starliner program since 2010, including expenses for spacecraft development, testing, and the government’s payment for six operational crew flights with Starliner.

It’s instructive to compare these costs with those of SpaceX’s Crew Dragon program, which started flying astronauts in 2020. All of NASA’s contracts with SpaceX for a similar scope of work on the Crew Dragon program totaled more than $3.1 billion, but any expenses paid by SpaceX are unknown because it is a privately held company.

SpaceX has completed all six of its original crew flights for NASA, while Boeing is at least a year away from starting operational service with Starliner. In light of Boeing’s delays, NASA extended SpaceX’s commercial crew contract to cover eight additional round-trip flights to the space station through the end of the 2020s.

Boeing’s leaders blame the structure of fixed-price contracts for the losses on the Starliner program. The aerospace giant has similar fixed-price contracts with the Pentagon to develop new two new Air Force One presidential transport aircraft, Air Force refueling tankers, refueling drones, and trainer airplanes. Boeing has reported losses on those programs, too.

SpaceX, meanwhile, has excelled with fixed-price contracts, which NASA uses on several elements of the Artemis program aiming to land astronauts on the Moon. For example, NASA selected SpaceX and Blue Origin, Jeff Bezos’s space company, for fixed-price contracts to develop human-rated lunar landers. SpaceX also won a fixed-price contract to provide NASA with a vehicle to deorbit the International Space Station at the end of its life.

Decision time

The first crew mission aboard Boeing’s Starliner spacecraft is expected to end sometime in August with the return of NASA astronauts Butch Wilmore and Suni Williams from the International Space Station. A successful conclusion of the test flight would pave the way for Boeing to start launching its backlog of six operational crew missions to the space station.

But it hasn’t been that simple. The Starliner test flight was initially expected to stay at the space station for at least eight days. Before the launch in June, NASA and Boeing officials left open the possibility for a mission extension, but managers didn’t anticipate Starliner to still be docked at the space station more than 50 days later.

Mission managers ordered Starliner to stay at the station through the rest of June and July while engineers investigated problems in the spacecraft’s propulsion system. There are helium leaks in Starliner’s service module, and the craft’s small maneuvering thrusters overheated during the final approach for docking at the space station.

NASA, which oversees Boeing’s commercial crew contract, is getting close to clearing Starliner for return to Earth, perhaps as soon as next week. On Saturday, ground controllers commanded Starliner to test-fire its maneuvering thrusters, and 27 of the 28 jets appeared to function normally despite overheating earlier in the mission. Despite the leaks, the spacecraft also has ample helium to pressurize its propulsion system, NASA officials said.

Before giving final approval for Starliner to undock from the space station and return to Earth, senior NASA leaders will convene a readiness review to go over the results of the investigation into the propulsion issues.

Boeing has some work to do to find a long-term fix for the helium leaks and overheating thrusters on future Starliner missions. NASA officials hoped a flawless Starliner test flight would allow the agency to formally certify the capsule for regular six-month expeditions to the space station by the end of the year, allowing Boeing to launch the first operational Starliner flight, known as Starliner-1, in February 2025.

Last week, NASA announced a six-month delay for the Starliner-1 mission to allow more time to solve the problems the spacecraft experienced on the crew test flight.

Boeing’s Starliner has cost at least twice as much as SpaceX’s Crew Dragon Read More »

7-million-pounds-of-meat-recalled-amid-deadly-outbreak

7 million pounds of meat recalled amid deadly outbreak

CDC, deaths, health, Infectious disease, listeria, Listeria monocytogenes, Meat, outbreak, recall, Science, USDA / /

7 million pounds across 71 products —

Authorities worry that the contaminated meats are still sitting in people’s fridges.

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Shelves sit empty where Boar's Head meats are usually displayed at a Safeway store on July 31, 2024, in San Anselmo, California.

Enlarge / Shelves sit empty where Boar’s Head meats are usually displayed at a Safeway store on July 31, 2024, in San Anselmo, California.

Over 7 million pounds of Boar’s Head brand deli meats are being recalled amid a bacterial outbreak that has killed two people. The outbreak, which began in late May, has sickened a total of 34 people across 13 states, leading to 33 hospitalizations, according to the US Department of Agriculture.

On June 26, Boar’s Head recalled 207,528 pounds of products, including liverwurst, beef bologna, ham, salami, and “heat and eat” bacon. On Tuesday, the Jarratt, Virginia-based company expanded the recall to include about 7 million additional pounds of meat, including 71 different products sold on the Boar’s Head and Old Country brand labels. The products were sold nationwide.

The meats may be contaminated with Listeria monocytogenes, a foodborne pathogen that is particularly dangerous to pregnant people, people over the age of 65, and people with compromised immune systems. Infections during pregnancy can cause miscarriage, stillbirth, premature delivery, or a life-threatening infection in newborns. For others who develop invasive illness, the fatality rate is nearly 16 percent. Symptoms of listeriosis can include fever, muscle aches, headache, stiff neck, confusion, loss of balance, and convulsions that are sometimes preceded by diarrhea or other gastrointestinal symptoms.

The problem was discovered when the Maryland Department of Health—working with the Baltimore City Health Department—collected an unopened liverwurst product from a retail store and found that it was positive for L. monocytogenes. In later testing, the strain in the liverwurst was linked to those isolated from people sickened in the outbreak.

According to the Centers for Disease Control and Prevention, six of the 34 known cases were identified in Maryland, and 12 were identified in New York. The other 11 states have only reported one or two cases each. However, the CDC expects the true number of infections to be much higher, given that many people recover without medical care and, even if people did seek care, health care providers do not routinely test for L. monocytogenes in people with mild gastrointestinal illnesses.

In the outbreak so far, there has been one case in a pregnant person, who recovered and remained pregnant. The two deaths occurred in New Jersey and Illinois.

In a statement on the company’s website, Boar’s Head said that it learned from the USDA on Monday night that L. monocytogenes strain in the liverwurst linked to the multistate outbreak. “Out of an abundance of caution, we decided to immediately and voluntarily expand our recall to include all items produced at the Jarratt facility. We have also decided to pause ready-to-eat operations at this facility until further notice. As a company that prioritizes safety and quality, we believe it is the right thing to do.”

The USDA said it is “concerned that some product may be in consumers’ refrigerators and in retail deli cases.” The USDA, the company, and CDC warn people not to eat the recalled products. Instead, they should either be thrown away or returned to the store where they were purchased for a full refund. And if you’ve purchased one of the recalled products, the USDA also advises you to thoroughly clean your fridge to prevent cross-contamination.

7 million pounds of meat recalled amid deadly outbreak Read More »

how-kepler’s-400-year-old-sunspot-sketches-helped-solve-a-modern-mystery

How Kepler’s 400-year-old sunspot sketches helped solve a modern mystery

astronomy, astrophysics, Johannes Kepler, Physics, Science, solar physics, sun spots / /
A naked-eye sunspot group on 11 May 2024

Enlarge / A naked-eye sunspot group on May 11, 2024. There are typically 40,000 to 50,000 sunspots observed in ~11-year solar cycles.

E. T. H. Teague

A team of Japanese and Belgian astronomers has re-examined the sunspot drawings made by 17th century astronomer Johannes Kepler with modern analytical techniques. By doing so, they resolved a long-standing mystery about solar cycles during that period, according to a recent paper published in The Astrophysical Journal Letters.

Precisely who first observed sunspots was a matter of heated debate in the early 17th century. We now know that ancient Chinese astronomers between 364 and 28 BCE observed these features and included them in their official records. A Benedictine monk in 807 thought he’d observed Mercury passing in front of the Sun when, in reality, he had witnessed a sunspot; similar mistaken interpretations were also common in the 12th century. (An English monk made the first known drawings of sunspots in December 1128.)

English astronomer Thomas Harriot made the first telescope observations of sunspots in late 1610 and recorded them in his notebooks, as did Galileo around the same time, although the latter did not publish a scientific paper on sunspots (accompanied by sketches) until 1613. Galileo also argued that the spots were not, as some believed, solar satellites but more like clouds in the atmosphere or the surface of the Sun. But he was not the first to suggest this; that credit belongs to Dutch astronomer Johannes Fabricus, who published his scientific treatise on sunspots in 1611.

Kepler read that particular treatise and admired it, having made his sunspot observations using a camera obscura in 1607 (published in a 1609 treatise), which he initially thought was a transit of Mercury. He retracted that report in 1618, concluding that he had actually seen a group of sunspots. Kepler made his solar drawings based on observations conducted both in his own house and in the workshop of court mechanic Justus Burgi in Prague.  In the first case, he reported “a small spot in the size of a small fly”; in the second, “a small spot of deep darkness toward the center… in size and appearance like a thin flea.”

The earliest datable sunspot drawings based on Kepler's solar observations with camera obscura in May 1607.

Enlarge / The earliest datable sunspot drawings based on Kepler’s solar observations with camera obscura in May 1607.

Public domain

The long-standing debate that is the subject of this latest paper concerns the period from around 1645 to 1715, during which there were very few recorded observations of sunspots despite the best efforts of astronomers. This was a unique event in astronomical history. Despite only observing some 59 sunspots during this time—compared to between 40,000 to 50,000 sunspots over a similar time span in our current age—astronomers were nonetheless able to determine that sunspots seemed to occur in 11-year cycles.

German astronomer Gustav Spörer noted the steep decline in 1887 and 1889 papers, and his British colleagues, Edward and Annie Maunder, expanded on that work to study how the latitudes of sunspots changed over time. That period became known as the “Maunder Minimum.” Spörer also came up with “Spörer’s law,” which holds that spots at the start of a cycle appear at higher latitudes in the Sun’s northern hemisphere, moving to successively lower latitudes in the southern hemisphere as the cycle runs its course until a new cycle of sunspots begins in the higher latitudes.

But precisely how the solar cycle transitioned to the Maunder Minimum has been far from clear. Reconstructions based on tree rings have produced conflicting data. For instance, one such reconstruction concluded that the gradual transition was preceded either by an extremely short solar cycle of about five years or an extremely long solar cycle of about 16 years. Another tree ring reconstruction concluded the solar cycle would have been of normal 11-year duration.

Independent observational records can help resolve the discrepancy. That’s why Hisashi Hayakawa of Nagoya University in Japan and co-authors turned to Kepler’s drawings of sunspots for additional insight, which predate existing telescopic observations by several years.

How Kepler’s 400-year-old sunspot sketches helped solve a modern mystery Read More »

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Webb confirms: Big, bright galaxies formed shortly after the Big Bang

astronomy, cosmology, galaxies, galaxy formation, Science, Webb telescope / /

They grow up so fast —

Structure of galaxy rules out early, bright objects were supermassive black holes.

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Image of a field of stars and galaxies.

Enlarge / Some of the galaxies in the JADES images.

One of the things that the James Webb Space Telescope was designed to do was look at some of the earliest objects in the Universe. And it has already succeeded spectacularly, imaging galaxies as they existed just 250 million years after the Big Bang. But these galaxies were small, compact, and similar in scope to what we’d consider a dwarf galaxy today, which made it difficult to determine what was producing their light: stars or an actively feeding supermassive black hole at their core.

This week, Nature is publishing confirmation that some additional galaxies we’ve imaged also date back to just 300 million years after the Big Bang. Critically, one of them is bright and relatively large, allowing us to infer that most of its light was coming from a halo of stars surrounding its core, rather than originating in the same area as the central black hole. The finding implies that it formed through a continuing burst of star formation that started just 200 million years after the Big Bang.

Age checks

The galaxies at issue here were first imaged during the JADES (JWST Advanced Deep Extragalactic Survey) imaging program, which includes part of the area imaged for the Hubble Ultra Deep Field. Initially, old galaxies were identified by using a combination of filters on one of Webb’s infrared imaging cameras.

Most of the Universe is made of hydrogen, and figuring out the age of early galaxies involves looking for the most energetic transitions of hydrogen’s electron, called the Lyman series. These transitions produce photons that are in the UV area of the spectrum. But the redshift of light that’s traveled for billions of years will shift these photons into the infrared area of the spectrum, which is what Webb was designed to detect.

What this looks like in practice is that hydrogen-dominated material will emit a broad range of light right up to the highest energy Lyman transition. Above that energy, photons will be sparse (they may still be produced by things like processes that accelerate particles). This point in the energy spectrum is called the “Lyman break,” and its location on the spectrum will change based on how distant the source is—the greater the distance to the source, the deeper into the infrared the break will appear.

Initial surveys checked for the Lyman break using filters on Webb’s cameras that cut off different areas of the IR spectrum. Researchers looked for objects that showed up at low energies but disappeared when a filter that selected for higher-energy infrared photons was swapped in. The difference in energies between the photons allowed through by the two filters can provide a rough estimate of where the Lyman break must be.

Locating the Lyman break requires imaging with a spectrograph, which can sample the full spectrum of near-infrared light. Fortunately, Webb has one of those, too. The newly published study involved turning the NIRSpec onto three early galaxies found in the JADES images.

Too many, too soon

The researchers involved in the analysis only ended up with data from two of these galaxies. NIRSpec doesn’t gather as much light as one of Webb’s cameras can, and so the faintest of the three just didn’t produce enough data to enable analysis. The other two, however, produced very clear data that placed the galaxies at a redshift measure roughly z = 14, which means we’re seeing them as they looked 300 million years after the Big Bang. Both show sharp Lyman breaks, with the amount of light dropping gradually as you move further into the lower-energy part of the spectrum.

There’s a slight hint of emissions from heavily ionized carbon atoms in one of the galaxies, but no sign of any other specific elements beyond hydrogen.

One of the two galaxies was quite compact, so similar to the other galaxies of this age that we’d confirmed previously. But the other, JADES-GS-ZZ14-0, was quite distinct. For starters, it’s extremely bright, being the third most luminous distant galaxy out of hundreds we’ve imaged so far. And it’s big enough that it’s not possible for all its light to be originating from the core. That rules out the possibility that what we’re looking at is a blurred view of an active galactic nucleus powered by a supermassive black hole feeding on material.

Instead, much of the light we’re looking at seems to have originated in the stars of JADES-GS-ZZ14-0. Most of those stars are young, and there seems to be very little of the dust that characterizes modern galaxies. The researchers estimate that star formation started at least 100 million years earlier (meaning just 200 million years after the Big Bang) and continued at a rapid pace in the intervening time.

Combined with earlier data, the researchers write that this confirms that “bright and massive galaxies existed already only 300 [million years] after the Big Bang, and their number density is more than ten times higher than extrapolations based on pre-JWST observations.” In other words, there were a lot more galaxies around in the early Universe than we thought, which could pose some problems for our understanding of the Universe’s contents and their evolution.

Meanwhile, the early discovery of the extremely bright galaxy implies that there are a number of similar ones out there awaiting our discovery. This means there’s going to be a lot of demand for time on NIRSpec in the coming years.

Nature, 2024. DOI: 10.1038/s41586-024-07860-9  (About DOIs).

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With a landmark launch, the Pentagon is finally free of Russian rocket engines

atlas v, cape canaveral, launch, military space, rd-180, russia, Science, Space, space force, united launch alliance, US Space Force, ussf-51 / /
Liftoff of ULA's Atlas V rocket on the US Space Force's USSF-51 mission.

Enlarge / Liftoff of ULA’s Atlas V rocket on the US Space Force’s USSF-51 mission.

United Launch Alliance delivered a classified US military payload to orbit Tuesday for the last time with an Atlas V rocket, ending the Pentagon’s use of Russian rocket engines as national security missions transition to all-American launchers.

The Atlas V rocket lifted off from Cape Canaveral Space Force Station in Florida at 6: 45 am EDT (10: 45 UTC) Tuesday, propelled by a Russian-made RD-180 engine and five strap-on solid-fueled boosters in its most powerful configuration. This was the 101st launch of an Atlas V rocket since its debut in 2002, and the 58th and final Atlas V mission with a US national security payload since 2007.

The US Space Force’s Space Systems Command confirmed a successful conclusion to the mission, code-named USSF-51, on Tuesday afternoon. The rocket’s Centaur upper stage released the top secret USSF-51 payload about seven hours after liftoff, likely in a high-altitude geostationary orbit over the equator. The military did not publicize the exact specifications of the rocket’s target orbit.

“What a fantastic launch and a fitting conclusion for our last national security space Atlas V (launch),” said Walt Lauderdale, USSF-51 mission director at Space Systems Command, in a post-launch press release. “When we look back at how well Atlas V met our needs since our first launch in 2007, it illustrates the hard work and dedication from our nation’s industrial base. Together, we made it happen, and because of teams like this, we have the most successful and thriving launch industry in the world, bar none.”

RD-180’s long goodbye

The launch Tuesday morning was the end of an era born in the 1990s when US government policy allowed Lockheed Martin, the original developer of the Atlas V, to use Russian rocket engines during its first stage. There was a widespread sentiment in the first decade after the fall of the Soviet Union that the United States and other Western nations should partner with Russia to keep the country’s aerospace workers employed and prevent “rogue states” like Iran or North Korea from hiring them.

At the time, the Pentagon was procuring new rockets to replace legacy versions of the Atlas, Delta, and Titan rocket families, which had been in service since the late 1950s or early 1960s.

A cluster of solid rocket boosters surround the RD-180 main engine as the Atlas V launcher climbs away from Cape Canaveral Space Force Station to begin the USSF-51 mission.

Enlarge / A cluster of solid rocket boosters surround the RD-180 main engine as the Atlas V launcher climbs away from Cape Canaveral Space Force Station to begin the USSF-51 mission.

Ultimately, the Air Force chose Lockheed Martin’s Atlas V and Boeing’s Delta IV rocket for development in 1998. The Atlas V, with its Russian main engine, was somewhat less expensive than the Delta IV and the more successful of the two designs. After Tuesday’s launch, 15 more Atlas V rockets are booked to fly payloads for commercial customers and NASA, mainly for Amazon’s Kuiper network and Boeing’s Starliner crew spacecraft. The 45th and final Delta IV launch occurred in April.

Boeing and Lockheed Martin merged their rocket divisions in 2006 to form a 50-50 joint venture named United Launch Alliance, which became the sole contractor certified to carry large US military satellites to orbit until SpaceX started launching national security missions in 2018.

SpaceX filed a lawsuit in 2014 to protest the Air Force’s decision to award ULA a multibillion-dollar sole-source contract for 36 Atlas V and Delta IV rocket booster cores. The litigation started soon after Russia’s military occupation and annexation of Crimea, which prompted US government sanctions on prominent Russian government officials, including Dmitry Rogozin, then Russia’s deputy prime minister and later the head of Russia’s space agency.

Rogozin, known for his bellicose but usually toothless rhetoric, threatened to halt exports of RD-180 engines for US military missions on the Atlas V. That didn’t happen until Russia finally stopped engine exports to the United States in 2022, following its full-scale invasion of Ukraine. At that point, ULA already had all the engines it needed to fly out all of its remaining Atlas V rockets. This export ban had a larger effect on Northrop Grumman’s Antares rocket, which also used Russian engines, forcing the development of a brand new first stage booster with US engines.

The SpaceX lawsuit, Russia’s initial military incursions into Ukraine in 2014, and the resulting sanctions marked the beginning of the end for the Atlas V rocket and ULA’s use of the Russian RD-180 engine. The dual-nozzle RD-180, made by a Russian company named NPO Energomash, consumes kerosene and liquid oxygen propellants and generates 860,000 pounds of thrust at full throttle.

With a landmark launch, the Pentagon is finally free of Russian rocket engines Read More »

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SpaceX moving Dragon splashdowns to Pacific to solve falling debris problem

commercial crew, dragon, human spaceflight, international space station, NASA, Science, Space, spacex / /
A Crew Dragon spacecraft is seen docked at the International Space Station in 2022. The section of the spacecraft on the left is the pressurized capsule, while the rear section, at right, is the trunk.

Enlarge / A Crew Dragon spacecraft is seen docked at the International Space Station in 2022. The section of the spacecraft on the left is the pressurized capsule, while the rear section, at right, is the trunk.

NASA

Sometime next year, SpaceX will begin returning its Dragon crew and cargo capsules to splashdowns in the Pacific Ocean and end recoveries of the spacecraft off the coast of Florida.

This will allow SpaceX to make changes to the way it brings Dragons back to Earth and eliminate the risk, however tiny, that a piece of debris from the ship’s trunk section might fall on someone and cause damage, injury, or death.

“After five years of splashing down off the coast of Florida, we’ve decided to shift Dragon recovery operations back to the West Coast,” said Sarah Walker, SpaceX’s director of Dragon mission management.

Public safety

In the past couple of years, landowners have discovered debris from several Dragon missions on their property, and the fragments all came from the spacecraft’s trunk, an unpressurized section mounted behind the capsule as it carries astronauts or cargo on flights to and from the International Space Station.

SpaceX returned its first 21 Dragon cargo missions to splashdowns in the Pacific Ocean southwest of Los Angeles. When an upgraded human-rated version of Dragon started flying in 2019, SpaceX moved splashdowns to the Atlantic Ocean and the Gulf of Mexico to be closer to the company’s refurbishment and launch facilities at Cape Canaveral, Florida. The benefits of landing near Florida included a faster handover of astronauts and time-sensitive cargo back to NASA and shorter turnaround times between missions.

The old version of Dragon, known as Dragon 1, separated its trunk after the deorbit burn, allowing the trunk to fall into the Pacific. With the new version of Dragon, called Dragon 2, SpaceX changed the reentry profile to jettison the trunk before the deorbit burn. This meant that the trunk remained in orbit after each Dragon mission, while the capsule reentered the atmosphere on a guided trajectory. The trunk, which is made of composite materials and lacks a propulsion system, usually takes a few weeks or a few months to fall back into the atmosphere and doesn’t have control of where or when it reenters.

Air resistance from the rarefied upper atmosphere gradually slows the trunk’s velocity enough to drop it out of orbit, and the amount of aerodynamic drag the trunk sees is largely determined by fluctuations in solar activity.

SpaceX and NASA, which funded a large portion of the Dragon spacecraft’s development, initially determined the trunk would entirely burn up when it reentered the atmosphere and would pose no threat of surviving reentry and causing injuries or damaging property. However, that turned out to not be the case.

In May, a 90-pound chunk of a SpaceX Dragon spacecraft that departed the International Space Station fell on the property of a “glamping” resort in North Carolina. At the same time, a homeowner in a nearby town found a smaller piece of material that also appeared to be from the same Dragon mission.

These events followed the discovery in April of another nearly 90-pound piece of debris from a Dragon capsule on a farm in the Canadian province of Saskatchewan. SpaceX and NASA later determined the debris fell from orbit in February, and earlier this month, SpaceX employees came to the farm to retrieve the wreckage, according to CBC.

Pieces of a Dragon spacecraft also fell over Colorado last year, and a farmer in Australia found debris from a Dragon capsule on his land in 2022.

SpaceX moving Dragon splashdowns to Pacific to solve falling debris problem Read More »

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Air pollution makes it harder for bees to smell flowers

air pollution, bees, pollination, pollinators, Science, syndication / /

protect the pollinators —

Contaminants can alter plant odors and warp insects’ senses, disrupting the process of pollination.

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Scientists are uncovering various ways that air pollution can interfere with the ability of insects to pollinate plants.

Scientists are uncovering various ways that air pollution can interfere with the ability of insects to pollinate plants.

In the summers of 2018 and 2019, ecologist James Ryalls and his colleagues would go out to a field near Reading in southern England to stare at the insects buzzing around black mustard plants. Each time a bee, hoverfly, moth, butterfly, or other insect tried to get at the pollen or nectar in the small yellow flowers, they’d make a note.

It was part of an unusual experiment. Some patches of mustard plants were surrounded by pipes that released ozone and nitrogen oxides—polluting gases produced around power plants and conventional cars. Other plots had pipes releasing normal air.

The results startled the scientists. Plants smothered by pollutants were visited by up to 70 percent fewer insects overall, and their flowers received 90 percent fewer visits compared with those in unpolluted plots. The concentrations of pollutants were well below what US regulators consider safe. “We didn’t expect it to be quite as dramatic as that,” says study coauthor Robbie Girling, an entomologist at the University of Southern Queensland in Australia and a visiting professor at the University of Reading.

A growing body of research suggests that pollution can disrupt insect attraction to plants—at a time when many insect populations are already suffering deep declines due to agricultural chemicals, habitat loss, and climate change. Around 75 percent of wild flowering plants and around 35 percent of food crops rely on animals to move pollen around, so that plants can fertilize one another and form seeds. Even the black mustard plants used in the experiment, which can self-fertilize, exhibited a drop of 14 percent to 31 percent in successful pollination as measured by the number of seedpods, seeds per pod, and seedpod weight from plants engulfed by dirty air.

Scientists are still working out how strong and widespread these effects of pollution are, and how they operate. They’re learning that pollution may have a surprising diversity of effects, from changing the scents that draw insects to flowers to warping the creatures’ ability to smell, learn, and remember.

This research is still young, says Jeff Riffell, a neuroscientist at the University of Washington. “We’re only touching the tip of the iceberg, if you will, in terms of how these effects are influencing these pollinators.”

Altered scents

Insects often rely on smell to get around. As they buzz about in their neighborhoods, they learn to associate flowers that are good sources of nectar and pollen with their scents. Although some species, like honeybees, also use directions from their hive mates and visual landmarks like trees to navigate, even they critically depend on the sense of smell for sniffing out favorite flowers from afar. Nocturnal pollinators such as moths are particularly talented smellers. “They can smell these patches of flowers from a kilometer away,” Riffell says.

One of the effects of pollution—and what Girling suspects was largely responsible for the pollination declines at the England site—is how it perturbs these flowery aromas. Each fragrance is a unique blend of dozens of compounds that are chemically reactive and degrade in the air. Gases such as ozone or nitrogen oxide will quickly react with these molecules and cause odors to vanish even faster than usual. “For very reactive scents, the plume can only travel a third of the distance than it should actually travel when there is no pollution,” says atmospheric scientist Jose D. Fuentes of Penn State University, who has simulated the influence of ozone on floral scent compounds.

And if some compounds degrade faster than others, the bouquet of scents that insects associate with particular plants transforms, potentially rendering them unrecognizable. Girling and his colleagues observed this in experiments in a wind tunnel into which they delivered ozone. The tunnel was also outfitted with a device that steadily released a synthetic blend of floral odors (an actual flower would have wilted, says coauthor Ben Langford, an atmospheric chemist at the UK Centre for Ecology & Hydrology). Using chemical detectors, the team watched the flowery scent plume shorten and narrow as ozone ate away at the edges, with some compounds dropping off entirely as others persisted.

The scientists had trained honeybees to detect the original flowery scent by exposing them to the odor, then giving them sugar water—until they automatically stuck out their tongue-like proboscises to taste it upon smelling the scent. But when bees were tested with ozonated odor representing the edges of the scent plume, either 6 or 12 meters away from the source, only 32 percent and 10 percent, respectively, stuck out their proboscises. The bee is “sniffing a completely different odor at that point,” Langford says.

Researchers also have observed that striped cucumber beetles and buff-tailed bumblebees struggle to recognize their host plants above certain levels of ozone. Some of the most dramatic observations are at night, when extremely reactive pollutants called nitrate radicals accumulate. Riffell and colleagues recently found that about 50 percent fewer tobacco hornworm moths were attracted to the pale evening primrose when the plant’s aroma was altered by these pollutants, and white-lined sphinx moths didn’t recognize the scent at all. This reduced the number of seeds and fruits by 28 percent, the team found in outdoor pollination experiments. “It’s having a really big effect on the plant’s ability to produce seeds,” Riffell says.

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