The spaceenvironment is harsh and full of extreme radiation. Scientists designing spacecraft and satellites need materials that can withstand these conditions.
Metal-halide perovskites are a class of materials discovered in 1839 that are found abundantly in Earth’s crust. They absorb sunlight and efficiently convert it into electricity, making them a potentially good fit for space-based solar panels that can power satellites or future space habitats.
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Researchers make perovskites in the form of inks, then coat the inks onto glass plates or plastic, creating thin, filmlike devices that are lightweight and flexible.
Surprisingly, these thin-film solar cells perform as well as conventional silicon solar cells in laboratory demonstrations, even though they are almost 100 times thinner than traditional solar cells.
But these films can degrade if they’re exposed to moisture or oxygen. Researchers and industry are currently working on addressing these stability concerns for terrestrial deployment.
To test how they might hold up in space, my team developed a radiation experiment. We exposed perovskite solar cells to protons at both low and high energies and found a unique, new property.
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The high-energy protons healed the damage caused by the low-energy protons, allowing the device to recover and continue doing its job. The conventional semiconductors used for space electronics do not show this healing.
My team was surprised by this finding. How can a material that degrades when exposed to oxygen and moisture not only resist the harsh radiation of space but also self-heal in an environment that destroys conventional silicon semiconductors?
Materials that can tolerate extreme radiation and self-heal would change the game.
Researchers estimate that deploying just a few pounds of perovskite materials into space could generate up to 10,000,000 watts of power. It currently costs about US$4,000 per kilogram ($1,818 per pound) to launch materials into space, so efficient materials are important.
What still isn’t known
Our findings shed light on a remarkable aspect of perovskites – their tolerance to damage and defects. Perovskite crystals are a type of soft material, which means that their atoms can move into different states that scientists call vibrational modes.
Atoms in perovskites are normally arranged in a lattice formation. But radiation can knock the atoms out of position, damaging the material. The vibrations might help reposition the atoms back into place, but we’re still not sure exactly how this process works.
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What’s next?
Our findings suggest that soft materials might be uniquely helpful in extreme environments, including space.
But radiation isn’t the only stress that materials have to weather in space. Scientists don’t yet know how perovskites will fare when exposed to vacuum conditions and extreme temperature variations, along with radiation, all at once. Temperature could play a role in the healing behavior my team saw, but we’ll need to conduct more research to determine how.
These results tell us that soft materials could help scientists develop technology that works well in extreme environments. Future research could dive deeper into how the vibrations in these materials relate to any self-healing properties.
The Research Brief is a short take on interesting academic work.
theconversation.com – Mustafa Aksoy, Assistant Professor of Electrical & Computer Engineering, University at Albany, State University of New York – 2024-09-27 07:32:30
Most CubeSats weigh less than a bowling ball, and some are small enough to hold in your hand. But the impact these instruments are having on space exploration is gigantic. CubeSats – miniature, agile and cheap satellites – are revolutionizing how scientists study the cosmos.
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A standard-size CubeSat is tiny, about 4 pounds (roughly 2 kilograms). Some are larger, maybe four times the standard size, but others are no more than a pound.
Rather than carry many instruments with a vast array of purposes, these Lilliputian-size satellites typically focus on a single, specific scientific goal – whether discovering exoplanets or measuring the size of an asteroid. They are affordable throughout the space community, even to small startup, private companies and university laboratories.
Tiny satellites, big advantages
CubeSats’ advantages over larger satellites are significant. CubeSats are cheaper to develop and test. The savings of time and money means more frequent and diverse missions along with less risk. That alone increases the pace of discovery and space exploration.
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CubeSats don’t travel under their own power. Instead, they hitch a ride; they become part of the payload of a larger spacecraft. Stuffed into containers, they’re ejected into space by a spring mechanism attached to their dispensers. Once in space, they power on. CubeSats usually conclude their missions by burning up as they enter the atmosphere after their orbits slowly decay.
That is now changing. Satellites large and small are rapidly becoming the backbone of space research. These spacecrafts can now travel long distances to study planets and stars, places where human explorations or robot landings are costly, risky or simply impossible with the current technology.
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But the cost of building and launching traditional satellites is considerable. NASA’s lunar reconnaissance orbiter, launched in 2009, is roughly the size of a minivan and cost close to $600 million. The Mars reconnaissance orbiter, with a wingspan the length of a school bus, cost more than $700 million. The European Space Agency’s solar orbiter, a 4,000-pound (1,800-kilogram) probe designed to study the Sun, cost $1.5 billion. And the Europa Clipper – the length of a basketball court and scheduled to launch in October 2024 to the Jupiter moon Europa – will ultimately cost $5 billion.
These satellites, relatively large and stunningly complex, are vulnerable to potential failures, a not uncommon occurrence. In the blink of an eye, years of work and hundreds of millions of dollars could be lost in space.
Exploring the Moon, Mars and the Milky Way
Because they are so small, CubeSats can be released in large numbers in a single launch, further reducing costs. Deploying them in batches – known as constellations – means multiple devices can make observations of the same phenomena.
For example, as part of the Artemis I mission in November 2022, NASA launched 10 CubeSats. The satellites are now trying to detect and map water on the Moon. These findings are crucial, not only for the upcoming Artemis missions but to the quest to sustain a permanent human presence on the lunar surface. The CubeSats cost $13 million.
The MarCO CubeSats – two of them – accompanied NASA’s Insight lander to Mars in 2018. They served as a real-time communications relay back to Earth during Insight’s entry, descent and landing on the Martian surface. As a bonus, they captured pictures of the planet with wide-angle cameras. They cost about $20 million.
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CubeSats have also studied nearby stars and exoplanets, which are worlds outside the solar system. In 2017, NASA’s Jet Propulsion Laboratory deployed ASTERIA, a CubeSat that observed 55 Cancri e, also known as Janssen, an exoplanet eight times larger than Earth, orbiting a star 41 light years away from us. In reconfirming the existence of that faraway world, ASTERIA became the smallest space instrument ever to detect an exoplanet.
Two more notable CubeSat space missions are on the way: HERA, scheduled to launch in October 2024, will deploy the European Space Agency’s first deep-space CubeSats to visit the Didymos asteroid system, which orbits between Mars and Jupiter in the asteroid belt.
And the M-Argo satellite, with a launch planned for 2025, will study the shape, mass and surface minerals of a soon-to-be-named asteroid. The size of a suitcase, M-Argo will be the smallest CubeSat to perform its own independent mission in interplanetary space.
The swift progress and substantial investments already made in CubeSat missions could help make humans a multiplanetary species. But that journey will be a long one – and depends on the next generation of scientists to develop this dream.
Delving into the presidential candidates’ successes on a number of drug-pricing policies, you’ll see a continuation of progress across the administrations. Neither the Trump administration nor the Biden-Harris administration, however, has done anything to truly lower drug prices for the majority of Americans.
$35 insulin
Insulin is a necessity for patients with diabetes. But from January 2014 to April 2019, the average price per unit went from US$0.22 to $0.34 before dropping back slightly by July 2023 to $0.29 per unit. Since dosing is weight-based, insulin costs for someone weighing 154 pounds would have risen from $231 to $357 a month from 2014 to 2019 and dropped to $305 a month by 2023. Price increases have led some patients to space out their medications by taking less than the dose they need for good blood sugar control. One study estimated that over 25% of patients in an urban diabetes center were underusing their insulin.
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In July 2020, the Trump administration enacted a $35 cap on insulin copayments via executive order. In effect, it made participating Medicare Part D programs limit the price of just one of each type of insulin product to $35. For instance, if there were six short-acting insulin products on an insurance plan’s approved drug list, the insurer had to offer one vial form and one pen form at $35.
In August 2022, the Biden-Harris administration signed the Inflation Reduction Act into law. This maintained the $35 insulin cap with the same stipulations but made the program mandatory for all Medicare Part D and Medicare Part B members. This expanded the number of people who could benefit from cheaper insulin to 3.3 million.
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This still doesn’t help a majority of diabetics. If you don’t have Medicare, the $35 reduction does not apply to you. Furthermore, pharmaceutical companies are not responsible for lowering insulin costs under these policies, but health plans are on the hook for lowering copayments. Costs could be passed along to beneficiaries in future Medicare premiums.
Importing Canadian drugs
Americans pay nearly 2.6 times more for prescription drugs than people in other high-income countries. One way regulators have tried to reduce prices is to simply import drugs at the prices pharmaceutical companies charge those countries rather than those charged to U.S. consumers.
In July 2019, the Trump administration proposed importing drugs from Canada as a way to share Canadians’ lower drug costs with American consumers. He signed an executive order allowing the Food and Drug Administration to create the rules under which states could import the drugs. When President Joe Biden came into office, he left the executive order in place and the rulemaking process continued.
No state under the Trump or Biden-Harris administrations has yet been able to successfully import a Canadian drug product. In January 2024, however, the Food and Drug Administration approved Florida’s plan to import Canadian drugs, the first state to receive the green light. Colorado, New Hampshire, New Mexico and Texas have applications pending as of September 2024.
Unfortunately, it is unlkely that Canada would allow their prescription drugs to be shipped in large quantities to American consumers, not without imposing high tariffs as a disincentive. That is because drug manufacturers could limit supplies to Canada and cause shortages if drugs are moved to the U.S. Manufacturers could also be less willing to negotiate lower prices for Canadians if that will hurt U.S. profits.
Negotiating with the pharmaceutical industry
Be it prescription drugs or cars, both buyer and seller must agree on a price for a successful sale to occur. If the potential buyer is unwilling to walk away from negotiations, you will not get the seller’s best price. One reason U.S. drug prices are higher than other countries’ is because the government is not a shrewd negotiator.
Negotiations that result in major reductions in drug prices frequently result from the drug manufacturer losing access to patients on a certain health plan or ending up in a higher drug tier that substantially raises a patient’s copay. However, if the buyer refuses the seller’s final offer, their members or citizens lose access to those drugs. While major private health plans and pharmacy benefit managers are able to directly negotiate drug prices with pharmaceutical manufacturers, often with substantial savings, Medicare was prevented from doing so by federal law until recently.
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In May 2018, the Trump administration released a so-called blueprint for reducing prescription drug prices that included negotiating Medicare prescription drug prices with the pharmaceutical industry. This plan wasn’t enacted during his term.
In August 2022, under the Biden-Harris administration, the Inflation Reduction Act enabled price negotiation and specified the number of drugs that negotiations could include in a year.
The first negotiation between Medicare and the pharmaceutical industry took place over the summer of 2024, lowering costs for 10 Medicare Part D drugs, which include the blood thinner Xarelto and the drugs Farxiga and Jardiance, which treat Type 2 diabetes, heart failure and kidney disease. The resulting $1.5 billion in savings will be extended in 2026 to the approximately 8.8 million Medicare Part D patients who are taking these drugs. The prices for these drugs are still twice what they are in four other developed countries.
Prices will be negotiated for another 15 Medicare Part D drugs in 2027. Thereafter, drug negotiations could include Medicare Part D drugs, which you pick up from your pharmacy, and Medicare Part B drugs, which are administered or received from your doctor’s office.
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Another aspect of the Inflation Reduction Act is capping out-of-pocket expenses at $2,000. This won’t go into effect until 2025, however, and simply shifts costs above the cap onto taxpayers.
Continuation of progress
It is often challenging to attribute policy successes to one administration versus another when assessing complex issues such as drug pricing. There were ideas initiated during the Trump administration that did not come to fruition until the Biden-Harris administration implemented and expanded on them.
For example, Medicare price negotiation, proposed in a Trump administration “blueprint,” was codified in law by President Biden, but the fruits of this policy will not be seen until the next administration. And regardless of who you attribute this success to, only a portion of people on Medicare will see any relief from high drug prices as a result.
Truly lowering the costs of prescription drugs would require identifying the maximum price the nation is willing to pay for benefits, such as cost per quality adjusted life year at the federal, state and private payer levels, and being willing to walk away from negotiations if the price exceeds that level. This would not be a panacea, though, especially for patients with rare and ultrarare diseases, and would need to be eased in over time to avoid bankrupting the industry.
As the climate warms, the southwestern U.S. is increasingly experiencing weather whiplash as the region swings from drought to flooding and back again. As a result, the public is hearing more about little-known infectious diseases, such as valley fever.
In 2023, California reported the second-highest number of valley fever cases on record, with more than 9,000 cases reported statewide. And between April 2023 and March 2024, California provisionally reported 10,593 cases – 40% more than during the same period the prior year.
The Conversation U.S. asked Jennifer Head, Simon Camponuri and Alexandra Heaney – researchers specializing in the epidemiology of valley fever – to explain what valley fever is, and what might explain its rise in recent years.
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What is valley fever, and how do you get infected?
When the fungus has access to moisture and nutrients, it grows long, branching fungal chains throughout the soil. When the soil dries out, these chains fragment to form fungal spores, which can be stirred up into the air when the soil is disturbed, such as by wind or digging. Airborne spores can then be inhaled and cause a respiratory infection.
Cases of valley fever are typically highest in California’s southern San Joaquin Valley and southern Arizona, but they have been increasing outside of these regions. Between 2000 and 2018, the incidence of valley fever cases increased fifteenfold in the northern San Joaquin Valley and eightfold along the Southern California coast. And between 2014 and 2018, incidence increased by more than eightfold along the central coast.
Because of these trends and the virulence of the pathogen that causes valley fever, it is listed as a priority pathogen by the World Health Organization. Historically, fungal infections have received very little attention and resources. By creating this list, the WHO is hoping to galvanize action surrounding listed pathogens, including getting more resources for research as well as the development of new treatments.
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What are the symptoms, and what should people be looking for?
After inhaling fungal spores from the environment, Coccidioides initially infects the lungs, causing symptoms like mild to severe cough, fever, difficulty breathing, chest pain and tiredness. Valley fever symptoms can resemble other common respiratory infections, so it’s important for people to get checked by a doctor if they’ve experienced prolonged symptoms, particularly if they have been given antibiotics that they are not responding to.
In California and Arizona, an estimated one-third of community-acquired pneumonia cases – or pneumonia acquired outside of the hospital – are caused by valley fever. However, only a fraction of community-acquired pneumonia cases get tested for it, so it’s likely the number of valley fever cases is significantly higher. Among diagnosed cases, half experienced symptoms for two months or more before being diagnosed.
In 5% to 10% of cases, the fungus can spread from the lungs to other parts of the body, such as the central nervous system, liver and bones, causing meningitis or arthritis-like symptoms. These cases can be severe and possibly fatal.
Researchers believe that patients are likely exposed to the fungus in the summer and early fall months, typically one to three months prior to their diagnosis. This delay accounts for time between when patients are exposed, develop symptoms and are diagnosed with the disease. While cases peak in the fall on average, seasonal strength and timing varies regionally.
This transition was followed by a near-record spike in cases in 2023. The state experienced another wet winter during the 2023-2024 wet season, furthering concern about continued high risk for valley fever in 2024.
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Our research team recently developed a model to forecast valley fever cases that will occur between April 2024 and March 2025 in California. We forecast that the state is likely to see another spike in cases during the fall and winter of 2024, on par with the spike in 2023.
During high-risk periods, clinicians should consider valley fever as a potential diagnosis. This is especially true when evaluating a patient presenting with valley fever symptoms or a respiratory illness who lives in, works in or traveled to an endemic or emerging region.
We are currently working to characterize seasonal disease patterns in Arizona as well, which are different from California’s. This is likely because Arizona has two rainy seasons.
Are some people at greater risk than others?
Those who spend time or work outdoors in areas where valley fever is common, especially where they may be exposed to dirt and dust, are more likely to get it.
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While healthy people are still at risk of infection, certain factors can increase the likelihood of developing severe disease from valley fever. These include being an adult 60 years or older, having diabetes, HIV or another condition that weakens the immune system, or being pregnant. People who are Black or Filipino also have been noted to have a higher risk of severe disease, which may relate to more exposure to the fungal spores, underlying health conditions, inequities in accessing care or other possible predispositions.
How can you protect yourself from getting valley fever?
People who live and work in the regions where the fungus is found should avoid exposure to dust as much as possible. When it is windy outside and the air is dusty, stay indoors and keep windows and doors closed.
When driving through a dusty area, limit vehicle speed, keep car windows closed and recirculate the air, if possible. When working outdoors, use dust suppression techniques, including wetting soil before digging to prevent stirring up dust, and installing fencing, windbreaks and vegetation where possible.
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For those who must directly stir up soil or be in dusty conditions, such as while doing construction or gardening work, consider using an N95 mask to limit dust inhalation.