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Why study space radiation? To keep astronauts safe – Brighter World

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A satellite built by McMaster students and researchers is heading into orbit to help protect astronauts as they travel further and stay out there longer. (Kayla Da Silva, McMaster University)


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With humanity eyeing space travel that would take astronauts beyond the low Earth orbit we’ve become accustomed to — say, on missions to Mars or beyond — it has become even more crucial to understand the long-term effects of space radiation. 

For the last eight years, a team of students and researchers at McMaster have been building a satellite designed to do just that. And it’s about to launch into space on board a SpaceX rocket.  

The satellite, named NEUDOSE — which is pronounced “new dose” and stands for Neutron Dosimetry (the measurement of radiation doses) and Exploration — is a state-of-the-art instrument capable of measuring the radiation levels that astronauts are exposed to in outer space.  

But to understand why a satellite that’s barely the size of a loaf of bread is such a monumental achievement, we first need to understand why space radiation poses such a major risk to astronauts and how this satellite will help address those risks.  

This little manoeuvre is going to cost us 

“Just like the sun produces light that we can see down here on Earth, the sun’s also emitting particles that are traveling through space,” explains Eric Johnston, co-Principal Investigator for the NEUDOSE mission and a McMaster graduate. 

In addition to this, stars and other objects also contribute to the overall radiation environment in outer space.   

Here on Earth, the majority of these particles are stopped by the atmosphere.  

But in space, that natural protection doesn’t exist, meaning these particles are free to interact with astronauts and spacecrafts.  

“Without that extra protection we’re used to having, radiation is a lot more damaging to astronauts,” says Johnston.  

Among other physiological effects, this damage includes the development of cancer, the formation of cataracts in the eyes, and cardiovascular issues, all of which can go undetected for years.  

And for the NEUDOSE team, it’s not hard to imagine how this risk could be amplified on deep space missions.  

Consider a human mission to Mars.  

It could take astronauts upward of nine months to reach the planet. In that time, astronauts may receive a dose of radiation equivalent to what a human on Earth would receive in their entire lifetime, explains McMaster grad Andrei Hanu, co-Principal Investigator on the NEUDOSE mission. 

Start factoring in time spent on the planet and travelling back to Earth and you can see why the effects of long-term exposure can be catastrophic.  

Houston, we have a problem 

But why is it so hard to protect humans from radiation in space? 

According to Johnston, we get a reminder of it every time we go for an X-ray. 

“If you imagine you’re going to get an X-ray at the hospital, they’ll put a lead vest on you,” he explains. “But there’s only so much lead and material we can bring up to space at any given time.” 

There’s also the fact that we don’t really know much about the quality of radiation up there — that is, the types and amounts of radiation present in space.  

“We’ve measured the bulk quantities to say, ‘Okay, we think it’s about this much damage,’” explains Johnston. “But the quality of radiation can really alter the long-term damage that might happen 20 or 30 years down the road.” 

This gap in knowledge makes it extremely difficult for experts to adequately prepare astronauts for lengthy deep space missions.  

“If we’re going to push astronauts further into space then we really need to understand the long-term effects of human space flight,” explains Johnston. “And to do that, we need to first know the quality of the radiation.” 

This is the way 

Shielding against all space radiation is an unrealistic goal, Hanu says. 

But there may be a more effective way to mitigate its effects.  

“A better approach would be to understand the space radiation environment,” explains Hanu.  

Doing so would allow experts to understand the types and levels of radiation present during missions and prepare adequate protections for those exposure levels.  

That’s where NEUDOSE comes in.  

The state-of-the-art device comprises two separate instruments. 

The first is a satellite that does everything you’d expect — namely, collect power from the sun and transmit data back to earth. According to Johnston, we can think of this instrument as the brains of the operation.  

The second instrument is a novel radiation detector that is designed to measure space radiation and determine the type of radiation present as well as its dose, all in real time. This device is one of the first tissue equivalent counters capable of measuring the quality of radiation.  

The data it collects will be transmitted back to a ground station at McMaster, where researchers will analyze the data and use its measurements to understand the long-term effects of space radiation. 

“Right now, this is a technology demonstration mission,” says Hanu. “But eventually NEUDOSE will be a standard radiation instrument for future missions to the Moon and eventually deep space.” 

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Giant prehistoric salmon had tusk-like teeth for defence, building nests: study – Times Colonist

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The artwork and publicity materials showcasing a giant salmon that lived five million years ago were ready to go to promote a new exhibit, when the discovery of two fossilized skulls immediately changed what researchers knew about the fish.

Initial fossil discoveries of the 2.7-metre-long salmon in Oregon in the 1970s were incomplete and had led researchers to mistakenly suggest the fish had fang-like teeth.

It was dubbed the “sabre-toothed salmon” and became a kind of mascot for the Museum of Natural and Cultural History at the University of Oregon, says researcher Edward Davis.

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But then came discovery of two skulls in 2014.

Davis, a member of the team that found the skulls, says it wasn’t until they got back to the lab that he realized the significance of the discovery that has led to the renaming of the fish in a new, peer-reviewed study.

“There were these two skulls staring at me with sideways teeth,” says Davis, an associate professor in the department of earth sciences at the university.

In that position, the tusk-like teeth could not have been used for biting, he says.

“That was definitely a surprising moment,” says Davis, who serves as director of the Condon Fossil Collection at the university’s Museum of Natural and Cultural History.

“I realized that all of the artwork and all of the publicity materials and bumper stickers and buttons and T-shirts we had just made two months prior, for the new exhibit, were all out of date,” he says with a laugh.

Davis is co-author of the new study in the journal PLOS One, which renames the giant fish the “spike-toothed salmon.”

It says the salmon used the tusk-like spikes for building nests to spawn, and as defence mechanisms against predators and other salmon.

The salmon lived about five million years ago at a time when Earth was transitioning from warmer to relatively cooler conditions, Davis says.

It’s hard to know exactly why the relatives of today’s sockeye went extinct, but Davis says the cooler conditions would have affected the productivity of the Pacific Ocean and the amount of rain feeding rivers that served as their spawning areas.

Another co-author, Brian Sidlauskas, says a fish the size of the spike-toothed salmon must have been targeted by predators such as killer whales or sharks.

“I like to think … it’s almost like a sledgehammer, these salmon swinging their head back and forth in order to fend off things that might want to feast on them,” he says.

Sidlauskas says analysis by the lead author of the paper, Kerin Claeson, found both male and female salmon had the “multi-functional” spike-tooth feature. 

“That’s part of our reason for hypothesizing that this tooth is multi-functional … It could easily be for digging out nests,” he says.

“Think about how big the (nest) would have to be for an animal of this size, and then carving it out in what’s probably pretty shallow water; and so having an extra digging tool attached to your head could be really useful.”

Sidlauskas says the giant salmon help researchers understand the boundaries of what’s possible with the evolution of salmon, but they also capture the human imagination and a sense of wonder about what’s possible on Earth.

“I think it helps us value a little more what we do still have, or I hope that it does. That animal is no longer with us, but it is a product of the same biosphere that sustains us.”

This report by The Canadian Press was first published April 24, 2024.

Brenna Owen, The Canadian Press

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Giant prehistoric salmon had tusk-like spikes used for defence, building nests: study

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A new paper says a giant salmon that lived five million years ago in the coastal waters of the Pacific Northwest used tusk-like spikes as defense mechanisms and for building nests to spawn.

The initial fossil discoveries of the 2.7-metre-long salmon in Oregon in the 1970s were incomplete and led researchers to suggest the fish had fang-like teeth.

The now-extinct fish was dubbed the “saber-tooth salmon,” but the study published in the peer-reviewed journal PLOS One today renames it the “spike-toothed salmon” and says both males and females possessed the “multifunctional” feature.

Study co-author Edward Davis says the revelation about the tusk-like teeth came after the discovery of fossilized skulls at a site in Oregon in 2014.

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Davis, an associate professor in the department of earth sciences at the University of Oregon, says he was surprised to see the skulls had “sideways teeth.”

Contrary to the belief since the 1970s, he says the teeth couldn’t have been used for any kind of biting.

“That was definitely a surprising moment,” Davis says of the fossil discovery in 2014. “I realized that all of the artwork and all of the publicity materials … we had just made two months prior, for the new exhibit, were all out of date.”

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SpaceX sends 23 Starlink satellites into low-Earth orbit

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April 23 (UPI) — SpaceX launched 23 Starlink satellites into low-Earth orbit Tuesday evening from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida.

Liftoff occurred at 6:17 EDT with a SpaceX Falcon 9 rocket sending the payload of 23 Starlink satellites into orbit.

The Falcon 9 rocket’s first-stage booster landed on an autonomous drone ship in the Atlantic Ocean after separating from the rocket’s second stage and its payload.

The entire mission was scheduled to take about an hour and 5 minutes to complete from launch to satellite deployment.

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The mission was the ninth flight for the first-stage booster that previously completed five Starlink satellite-deployment missions and three other missions.

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