Science
Nuclear Propulsion Could Help Get Humans to Mars Faster
This is from a NASA press release dated February 12, 2021…
As NASA’s Perseverance rover homes in on the Red Planet, engineers on the ground are furthering potential propulsion technologies for the first human missions to Mars. NASA is looking at two types of nuclear propulsion systems – nuclear electric and nuclear thermal propulsion.
Nuclear electric propulsion systems use propellants much more efficiently than chemical rockets but provide a low amount of thrust. They use a reactor to generate electricity that positively charges gas propellants like xenon or krypton, pushing the ions out through a thruster, which drives the spacecraft forward. Using low thrust efficiently, nuclear electric propulsion systems accelerate spacecraft for extended periods and can propel a Mars mission for a fraction of the propellant of high thrust systems.
Credits: NASA
Nuclear thermal propulsion technology provides high thrust and twice the propellant efficiency of chemical rockets. The system works by transferring heat from the reactor to a liquid propellant. That heat converts the liquid into a gas, which expands through a nozzle to provide thrust and propel a spacecraft.
NASA, in coordination with the Department of Energy (DOE), is asking industry for preliminary reactor design concepts for a nuclear thermal propulsion system. The agencies plan to fund several efforts to explore different approaches. Future follow-on contracts will generate more detailed reactor designs and build preliminary testing hardware.
“While NASA’s immediate priority is returning humans to the Moon with the Artemis program, we are also investing in ‘tall pole’ technologies that could enable crewed missions to Mars,” said Jim Reuter, associate administrator of NASA’s Space Technology Mission Directorate (STMD). “We look forward to seeing what innovations industry offer in nuclear propulsion as well as fission surface power via a forthcoming request for proposals for that technology.”
Human Missions to Mars
To date, only robotic explorers have traveled to Mars, without the need for returning to Earth. Waiting for optimal planetary alignment for the return trip would require astronauts to loiter at Mars for more than a year, stretching the round-trip mission to more than three years.
NASA’s goal is to minimize the time the crew travels between Earth and Mars to as close to two years as is practical. Space nuclear propulsion systems could enable shorter total mission times and provide enhanced flexibility and efficiency for mission designers.
To keep the round-trip crewed mission duration to about two years, at a minimum, NASA is looking at nuclear-enabled transportation systems to facilitate shorter-stay surface missions. The systems would take advantage of optimal planetary alignment for a low-energy transit for one leg of the trip and the new technology’s enhanced performance to make the higher-energy transit for the other leg.
It’s too soon to say what propulsion system will take the first astronauts to Mars, as there remains significant development required for each approach.
Illustration of a spacecraft with a nuclear-enabled propulsion system. Credits: NASA
Technology Readiness
NASA’s Marshall Space Flight Center in Huntsville, Alabama, leads the agency’s space nuclear propulsion project in partnership with a DOE team that includes scientists and engineers from Idaho National Laboratory, Los Alamos National Laboratory, and Oak Ridge National Laboratory. STMD’s Technology Demonstration Missions program funds the technology development.
Nuclear electric propulsion builds on NASA’s work maturing solar electric propulsion thrusters and systems for Artemis, as well as the development of fission power for the lunar surface. Significant investment has also been made in relevant fuel and reactor technologies for small, terrestrial reactors that could be adapted to space reactors to power electric propulsion. The U.S. government’s aim to establish a fuel fabrication capability has a range of applications, including nuclear propulsion and fission surface power.
Credits: NASA/Mick Speer
Nuclear thermal propulsion has been on NASA’s radar for more than 60 years. The new hardware design and development phase pursued through a request for proposals released Feb. 12, 2021, builds on existing efforts to mature crucial elements of a nuclear thermal propulsion system.
NASA, in partnership with DOE, is developing and testing new fuels that use low-enriched uranium for space applications to see how they perform under the extreme thermal and radiation environments needed for nuclear thermal propulsion. NASA is working closely with DOE, industry, and universities to put fuel samples in research reactors at Idaho National Laboratory’s Transient Reactor Test (TREAT) facility and the Massachusetts Institute of Technology Nuclear Reactor Laboratory for nuclear testing. The team is also performing non-nuclear testing in simulated reactors at Marshall test facilities.
“The reactor underpinning a nuclear thermal propulsion system is a significant technical challenge due to the very high operating temperatures needed to meet the propulsion performance goals,” explained Anthony Calomino, NASA’s nuclear technology portfolio lead within STMD.
While most of the engine operates at modest temperatures, materials in direct contact with the reactor fuel must be able to survive temperatures above 4,600 degrees Fahrenheit. NASA and DOE have been working with industry on a viable approach, and industry will now develop preliminary designs to meet this challenge.
Technology Infusion
“We’re exploring both nuclear electric and nuclear thermal propulsion options for crewed Mars missions,” Calomino said. “Each technology has its unique advantages and challenges that need to be carefully considered when determining the final preference.”
Whichever propulsion system is ultimately chosen, the fundamentals of nuclear propulsion can enable robust and efficient exploration beyond the Moon. NASA will continue to develop, test, and mature various propulsion technologies to reduce risk and inform the Mars transport architecture.
Source: NASA
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health and wellness
Warmer temps bring soaring tick populations – here’s how to stay safe from Lyme disease
Tick bites are rising in 2026. Learn where Lyme disease is spreading, early symptoms like the bull’s-eye rash, treatment options, and practical ways to prevent tick bites.
Lakshmi Chauhan, University of Colorado Anschutz
Spring’s warmer weather lures people outdoors – and into possible contact with ticks that spread Lyme disease.
Already, the 2026 tick season is booming. On April 23, the Centers for Disease Control and Prevention warned that emergency room visits due to tick bites are at their highest level since 2017. That may portend an especially severe season for Lyme disease and other tick-borne illnesses.
State health departments reported more than 89,000 cases of Lyme disease in 2023, the last year for which data is available. But public health experts believe that close to 500,000 people in the U.S. get Lyme disease every year.
As an infectious disease doctor with experience treating some of this infection’s long-term outcomes, I know that Lyme disease can be tricky because people often don’t notice tick bites and may overlook early symptoms of an infection. But left untreated, the infection can cause serious lingering – and even permanent – health issues.
Here’s what you need to know about Lyme disease to stay safe this season:
What causes Lyme disease?
Lyme disease, named after the Connecticut town where the disease was first identified in 1975, is caused by a group of bacteria called Borrelia – most often, the species Borrelia burgdorferi.
Deer ticks – also called black-legged ticks, and members of a group called Ixodes – transmit the disease after feeding on an infected animal, usually a bird, mouse or deer. When they then bite a person, they can transmit the bacteria into the person’s bloodstream.
Usually, the tick must attach for 24-48 hours to transmit the bacteria causing Lyme disease.
Where and when does Lyme disease occur?
Lyme disease can occur in most regions where deer ticks live.
These ticks are most active in late spring, summer and fall – usually April to November in most regions. They emerge when the temperature is above freezing. In years when winter is shorter, ticks can emerge earlier. And they may be active year-round in regions where freezing temperatures are rare.
Approximately 90% of U.S. cases are reported from states in the Northeast, mid-Atlantic from Virginia to eastern Canada, and Upper Midwest regions including Wisconsin, Michigan and Minnesota. A few cases occasionally pop up in California, Oregon and Washington.
Since 1995, the incidence of Lyme disease in the U.S. has almost doubled.
Warmer weather and changes in rainfall patterns now allow ticks to survive in new regions of the country – and for longer periods. But even in regions where ticks lived before, Lyme disease has become more common due to increases in deer populations. As woodland areas are increasingly being developed, it may be bringing the habitat of deer and mice closer to people, increasing the risk of transmission.
Lyme disease symptoms to watch for
Early symptoms of Lyme disease – fever, muscle aches and fatigue – generally emerge within three to 30 days after a tick bite. Another classic symptom in the first month is a target or bull’s eye rash at the site of tick bite, which occurs in about 70% to 80% of cases.
Other rashes following a tick bite can also occur. Some may be due to irritation from the bite, and not necessarily an infection.
If you know you’ve had a tick bite and experience flu-like symptoms – or if you see a bull’s-eye rash, whether you know you were bitten or not – it’s important to check with your healthcare provider about whether you should be treated with antibiotics.
A blood test for antibodies can help confirm the infection, but it can sometimes yield a false negative result, particularly in the first couple of weeks of the disease.
In most people, the rash goes away on its own. However, treatment may shorten its duration and is important for preventing other symptoms. A two- to four-week course of antibiotics can generally treat Lyme disease. Severe cases might require intravenous antibiotics.
A promising new vaccine for Lyme disease is currently being tested. In March 2026, Pfizer, the pharmaceutical company developing it, announced that in a late-stage study, the vaccine prevented the disease in 70% of people who received it.
Later Lyme symptoms
If left untreated, the bacteria that causes Lyme can spread, potentially causing longer-term symptoms. About 60% of people who get Lyme disease and don’t treat it can develop arthritis.
In rare cases, Lyme disease can also affect the heart and the nervous system. Inflammation in the brain or the tissues surrounding it, called meninges, can cause headaches and neck pain, as well as balance issues and memory and behavior changes. It can also cause nerve damage that results in numbness, tingling and muscle weakness.
These symptoms can appear right away or much later – sometimes months to years after infection. And in cases where the disease wasn’t promptly treated, late-stage symptoms can linger even after antibiotics kill the bacteria.
Scientists don’t fully understand why, but one intriguing study found that some particles from the bacteria’s cell wall leak into the joints and can persist after treatment, spurring ongoing inflammation and arthritis symptoms.
Another reason for Lyme’s long-term effects is that it can trigger autoimmune disease, which is when the immune system attacks its own cells. What’s more, because the nervous system may be particularly sensitive to damage caused by the bacteria and related inflammation, it may take an especially long time to heal. In some situations, the damage could be permanent.
Preventing Lyme disease
Until a vaccine becomes available, there are steps you and your family can take to help protect against Lyme disease:
- Use tick and insect repellents such as DEET and picaridin, which can be applied to skin, and permethrin, which is sprayed onto clothing, to keep ticks at bay. Treating clothing with permethrin may be especially beneficial, since the substance withstands several washes.
- Wear long-sleeve shirts and pants while you are gardening, hiking or walking through grass or woods to prevent tick bites. Wearing light-colored clothes makes ticks more visible, and tucking your pants into your socks can also prevent the little buggers from traveling from your pants, shoes and socks onto your legs.
- Remove your outdoor clothes immediately. Washing and drying clothes at high temperature can help kill any ticks that managed to hitch a ride. And a quick shower immediately after spending time outdoors can wash ticks off the skin before they have a chance to attach.
- If you spend time outdoors, perform daily tick checks, paying special attention to warm areas like your armpits, neck, ears and underwear line. If you find a tick attached, pull it off with tweezers, holding them perpendicular to the skin.
- If you find a tick that may have been on the skin for more than 36 hours, ask your healthcare provider whether a dose of preventive antibiotics – generally given within 72 hours of the bite – would be appropriate.
Lakshmi Chauhan, Associate Professor of Infectious Disease Medicine, University of Colorado Anschutz
This article is republished from The Conversation under a Creative Commons license. Read the original article.
The Knowledge
Artemis II crew brought a human eye and storytelling vision to the photos they took on their mission
Artemis II crew: Artemis II’s astronaut photos show how human perspective and storytelling make space imagery feel authentic—especially in an era of AI-generated visuals.
Christye Sisson, Rochester Institute of Technology
In early April 2026, the Artemis II mission captivated me and millions of people watching from across the world. The crew’s courage, skill and infectious wonder served as tangible proof of human persistence and technological achievement, all against the mysterious backdrop of space.
People back on Earth got to witness the mission through remarkable photos of space captured by astronauts. Images created and shared by astronauts underscore how photography builds a powerful, authentic connection that goes beyond what technology alone can capture.
As a photographer and the director of the Rochester Institute of Technology’s School of Photographic Arts and Sciences, I am especially drawn to how these photographs have been at the center of the public’s collective experience of this mission.
In an era when image authenticity is often questioned and with the capabilities of autonomous, AI-driven imaging, NASA’s choice to train astronauts in photography has placed meaning over convenience and prioritized their human perspectives and creativity.
Capturing space from the crew’s perspective
Photography was not originally placed as a high priority in NASA’s Apollo era. The astronauts only took photographs if they had the chance and all their other tasks were complete.
Thanks largely in part to public response to those images from Apollo, including “Earthrise” and the “Blue Marble” being widely credited for helping catalyze the modern environmental movement, NASA shifted its approach to utilize photography to help capture the public’s imagination by training their astronauts in photographic practices.
The Artemis II mission’s photographs have helped cut through the increasing volume of artificially generated images circulating on social media. NASA’s social media releases of the crew’s photographs have garnered thousands of shares and comments.
This excitement could be explained by the novelty of photos from space, but these images also distinguish themselves as products of astronauts experiencing these sights and interpreting them through their photographs. These differences require an important distinction around where technology ends and humanity begins.
Human perspective versus AI tools
Photography has long integrated AI-powered software and data-driven tools in a variety of ways: to process raw images, fill in missing color information, drive precise focus and guide image editing, among others. These modern technological assists help human photographers realize their vision.
Artificial intelligence is also increasingly capable of operating machinery competently and autonomously, from cars to drones and cameras.
And AI can generate convincing, realistic images and videos from nothing more than a text prompt, using readily available tools.
Researchers train AI to mimic patterns informed by millions of sample images, and the algorithm can then either take or create a photograph based on what it predicts would be the most likely version of a successful, believable image.
Human-created photos are rooted in direct observation, intent and lived experience, while AI images – or choices made by AI-driven tools – are not. While both can produce compelling and believable visuals, the human photographs carry emotional power because the photographer is drawing from their experiences and perspective in that moment to tell an authentic story.
Artemis II photographs resonate, not only because they are historic, but because they reflect the deliberate choices and intent of a human being in that specific moment and context. The exposure, camera setting, lens choice and composition are all dictated by the astronaut’s vision, skill, perspective and experience. Each image is unique in comparison with the others. These choices give the images narrative power, anchoring them in human perspective.
Images to tell a story
Photographers choose what to include in the final version of their image to tell a story. In the Artemis II images, this human perspective comes out. In the “Earthset” photo, you see a striking juxtaposition of the Moon’s monochromatic, textured surface in the foreground against a slivered, bright Earth.
The choice to include both in the frame contrasts these objects literally and figuratively, inviting comparison. It creates a narrative where Earth is contrasted against the Moon – life is contrasted against the absence of it.
Another photo shows the nightside of the whole Earth, featuring the Sun’s halo, auroras and city lights. The choice to include the subtle framing of the window of the capsule in the lower left corner reminds the viewer where and how this image was captured: by a human, inside a capsule, hurtling through space. That detail grounds the photograph in the human perspective.
Both photos are reminiscent of Earthrise and the Blue Marble. These past images hold a place in the global collective consciousness, shaped by a shared historical moment.
The Artemis II photographs are anchored in this collective moment of lived human experience, yet also shaped by each astronaut’s viewpoint. The crew’s unique perspectives exemplify photography’s transformative power by inviting viewers to engage emotionally and intellectually with their journey. These photographs share the astronauts’ awe and wonder and affirm the value of human creativity and its ability to connect us in a captured moment.
Christye Sisson, Professor of Photographic Sciences, Rochester Institute of Technology
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Science
Seeing an eclipse from Earth is awe‑inspiring – for astronauts seeing one from space, the scene was even more grand
Discover the stunning eclipse seen by Artemis II astronauts during their 2026 Moon mission. A truly extraordinary spectacle awaits.
Deana L. Weibel, Grand Valley State University
The astronauts on Artemis II’s trip to the Moon in April 2026 didn’t just have an amazing journey through space. They also saw something extraordinary. They were the first humans to see a total solar eclipse from space.
A solar eclipse happens when the Moon moves in front of the Sun. In a total eclipse, the Sun’s central disc is covered completely.
From Earth, the circle of the Sun is about the same size as the circle of the Moon. With the bright circle blocked, you can see the undulating rays of the Sun’s corona, or outer atmosphere, that are normally too dim to be observed.
I’m a cultural anthropologist who studies awe-inspiring aspects of space exploration. I have been lucky enough to have seen two total solar eclipses. The first one was in Nebraska in 2017, the second in Indiana in 2024.
During my second total eclipse, the period of totality – that short span when you can remove your protective glasses and look directly at the eclipse – lasted close to 4 minutes. I saw waves of diffuse light snaking around an ink-black hole in the sky. It looked very wrong – almost alien.
On Aug. 12, 2026, there will be another total solar eclipse, visible only from Greenland, Iceland, Spain and the Balearic Islands of the Mediterranean. Some fortunate viewers in Spain and nearby islands may see the eclipse just before sunset, low on the horizon. The Moon illusion, a phenomenon where the Moon looks bigger when it’s near the horizon, might make this eclipse look unusually large.
Unusual eclipse perspectives
Astronauts will occasionally also have less common eclipse experiences. I interviewed one I call by the pseudonym “Jackie” in my research about astronauts’ experiences of awe. She was part of an astronaut training group that did a flight exercise during a total solar eclipse.
Jackie and her squad flew their jets in the shadow of the Moon. This lengthened their time in totality because they could follow and stay within the shadow. Jackie was most impressed with how the Sun’s corona seemed to shift and ripple.
“It’s not static … it’s alive,” she told me.
On April 6, 2026, the astronauts of NASA’s Artemis II mission saw another kind of unusual eclipse as they flew around the Moon. At one point during their flight, the Moon and the spacecraft aligned so that the Moon was directly between them and the Sun, blocking the Sun’s disk in a way that looks very different from what we see on Earth.
Astronaut Victor Glover said it felt like they “just went sci-fi.” https://www.youtube.com/embed/YLjPci5bo1k?wmode=transparent&start=0 ‘An impressive sight’: The Artemis II crew were the first humans to observe a solar eclipse from near the Moon.
The astronauts were so close to the Moon that the Moon looked bigger than the Sun and hid more of its bright circle. Earth was also in view, and sunlight reflected from the Earth onto the Moon in a phenomenon NASA calls “earthshine.” This dim light is very similar to the moonlight that shines on the Earth at night.
Imagine the Sun hidden behind the Moon, creating a hazy halo around the Moon’s edges. At the same time, faint light reflected from Earth softly illuminates the Moon, revealing mountains and craters in a dim twilight. Now imagine this striking scene lasting 54 minutes.
This sight was, without a doubt, one of the most unusual eclipses ever seen by human eyes.
Although Artemis’ astronauts are trained to think scientifically, this experience propelled them into a state of awe. They talked openly about how their brains were “not processing” what they observed. While NASA kept them busy with a variety of tasks, the sound of emotion and excitement in their voices as they broadcast live from their lunar flyby was unmistakable.
The psychology of awe
Researchers have studied the effects of awe on the human brain, including awe felt during solar eclipses. Moments of wonder like these can transform how you feel and even how you think, making you more thoughtful and open-minded.
In my own work I’ve found these experiences can change how astronauts understand their own place in the universe.
One astronaut said she gained an awareness of the fragility of our planet that now shapes everything she does, while another described becoming more curious after returning to Earth. A third said the awe he experienced in lunar orbit changed his understanding of time and infinity.
Space travel creates many opportunities for awe, but a solar eclipse from behind the Moon, as Mission Commander Reid Wiseman put it, required “20 new superlatives.”
It’s an experience most of the earthbound eclipse-chasers heading to Greenland or Iceland or Spain this summer will only dream about. Whether eclipses happen in space or on Earth, though, close encounters with the grandeur of our universe can make you feel profoundly human.
Deana L. Weibel, Professor of Anthropology, Grand Valley State University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Dive into “The Knowledge,” where curiosity meets clarity. This playlist, in collaboration with STMDailyNews.com, is designed for viewers who value historical accuracy and insightful learning. Our short videos, ranging from 30 seconds to a minute and a half, make complex subjects easy to grasp in no time. Covering everything from historical events to contemporary processes and entertainment, “The Knowledge” bridges the past with the present. In a world where information is abundant yet often misused, our series aims to guide you through the noise, preserving vital knowledge and truths that shape our lives today. Perfect for curious minds eager to discover the ‘why’ and ‘how’ of everything around us. Subscribe and join in as we explore the facts that matter. https://stmdailynews.com/the-knowledge/
