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NASA to test nuclear fission-powered spacecraft engine by 2027

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The technological advancement has long been seen as critical to long-haul missions, including a manned trip to Mars.

The top official at the United States space agency NASA has said the country plans to test a spacecraft engine powered with nuclear fission by 2027, an advancement seen as key to long-haul missions including a manned journey to Mars.

NASA will partner with the US military’s Defense Advanced Research Projects Agency (DARPA) to develop the nuclear thermal propulsion engine and launch it into space, NASA administrator Bill Nelson said on Tuesday. The project has been named the Demonstration Rocket for Agile Cislunar Operations or DRACO.

“With the help of this new technology, astronauts could journey to and from deep space faster than ever – a major capability to prepare for crewed missions to Mars,” Nelson said in a statement.

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The announcement comes amid a new nuclear space race between the US, Russia and China, with the three superpowers working to expand their extraterrestrial nuclear capabilities, including for use propelling spacecraft and powering colonies on the moon.

A nuclear thermal rocket engine uses a fission reactor to generate extremely high temperatures. The heat is then transferred to a liquid propellant, which “is expanded and exhausted through a nozzle to propel the spacecraft”, according to NASA.

“A nuclear thermal rocket can be three or more times more efficient than conventional chemical propulsion,” according to the agency.

That means that a spacecraft powered by nuclear fission could result in faster travel times and less risk to astronauts. The technology could also allow for more power for instruments and communications on board.

The US has long used energy produced by radioactive material in its space work by harnessing the heat generated by its decay, according to the World Nuclear Association industry group.

The country, however, has not used nuclear fission, which creates energy from splitting atomic nuclei, on spacecraft due in part to the challenge of managing the extreme heat created by the process.

For its part, the International Atomic Energy Agency (IAEA) has long hailed nuclear thermal propulsion as critical to journeying farther into space.

“Nuclear technology has long played a vital role in prominent space missions,” Mikhail Chudakov, the IAEA’s deputy director general and head of its Department of Nuclear Energy, said in February 2022.

“But future missions could rely on nuclear-powered systems for a much broader spectrum of applications. Our pathway to the stars runs through the atom.”

Under the NASA-DARPA agreement, NASA’s Space Technology Mission Directorate will lead technical development of the nuclear thermal engine, which will eventually be integrated with an experimental spacecraft created by the military.

The agency said the last US nuclear thermal rocket engine tests were discontinued in the 1970s.

In a statement, Stefanie Tompkins, the director of DARPA, hailed the plans to develop the “leap-ahead” advance.

“The space domain is critical to modern commerce, scientific discovery, and national security,” she said.

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Giant prehistoric salmon had tusk-like teeth for defence, building nests

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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.

But then came discovery of two skulls in 2014.

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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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