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NASA’s Artemis splashdown will put Orion through a nail-biting test

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The Orion moonship may weigh 25 tons, but in a few days, it will skip like a slight pebble across a pond before plummeting thousands of feet through the air to its target in the Pacific Ocean.

The capsule has begun saying farewell to the moon, with just one more space flyby scheduled for Monday, Dec. 5, before heading home. Already NASA has deployed a crew to San Diego, California, to join the Navy at sea for training exercises to prepare for its unprecedented return.

NASA plans to bring Orion back with a so-called “skip entry” into Earth’s atmosphere. It’ll be the first time the U.S. space agency has ever tried the technique with a passenger spacecraft. The maneuver involves the moonship traveling at an unfathomably high speed and enduring scorching temperatures.

“Orion will come home faster and hotter than any spacecraft has before,” NASA Administrator Bill Nelson told reporters in August. “It’s going to hit the Earth’s atmosphere at 32 times the speed of sound, it’s going to dip into the atmosphere, and bleed off some of that speed, before it starts descending through the atmosphere.”

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Orion’s re-entry into Earth’s atmosphere will experience temperatures reaching 5,000 degrees Fahrenheit.
Credit: NASA

Mission leaders say the advantage is breaking up the intense G-force loads — the heavy feeling pushing against a body during extreme acceleration — into two smaller events rather than one severe episode. Though the capsule doesn’t have any people onboard now, NASA believes mastering the skip entry will keep Artemis astronauts who would experience those effects safer in the future. When humans are subjected to forces much greater than normal gravity, their hearts are put under tremendous stress, causing dizziness and sometimes blackouts.

But when the capsule comes back in about a week on Dec. 11, NASA will have to prove Orion can actually survive the ordeal. The re-entry into Earth’s atmosphere will be a nail-biting grand finale to Artemis’ maiden 25-day space voyage, with success hinging on the new Lockheed Martin-built heat shield. The hardware it’s protecting will have to withstand up to 5,000 degrees Fahrenheit, according to NASA.

Imagine an inferno half the temperature of the sun’s surface.

“That heat shield on the back end is going to show us how we’ve taken that material from the Apollo days and brought that into the 21st century,” said Kelly DeFazio, Lockheed’s Orion production director, in August. NASA hopes to put astronauts in Orion as early as 2024 for a ride around the moon. The first landing on the lunar surface would follow on Artemis III, possibly one year later.

NASA inspecting the heat shield after a test
The final objective for the Artemis I mission will be a test of the heat shield during re-entry into Earth’s atmosphere.
Credit: NASA

When Orion plunges toward Earth, it will be traveling 24,500 mph. By comparison, the Space Shuttle’s descent reached about 17,500 mph, Nelson said. That initial dip into the upper air will use the atmosphere to slow the capsule down to about 300 mph. Then, it will re-enter for a final descent, slowing down even more with parachutes.

By the time Orion hits water, it should be coasting at 20 mph. NASA will have live coverage of the event beginning at 11 a.m. ET, with the splashdown at about 12:40 p.m., on Dec. 11.


“Orion will come home faster and hotter than any spacecraft has before.”

The idea of a skip entry has existed on paper since NASA’s Apollo days half a century ago but was never attempted. Spaceships then didn’t have the navigational systems and computer power to execute it.

“Apollo was just strictly a direct entry, so that pretty much your landing site was set earlier on, when you departed the moon, with only a minor ability to adjust,” Chris Edelen, deputy manager for Orion integration, told Mashable during a briefing on Wednesday.

Apollo 12 astronauts emerging after spashdown
NASA astronaut Alan Bean emerges from the Apollo 12 spacecraft after it splashes down in the ocean in August 1969.
Credit: NASA

For Apollo missions, the spacecraft dipped into Earth’s atmosphere and then could travel up to 1,725 miles horizontally before plopping down into the ocean. A swarm of ships and rafts dispersed at sea waited on standby for the recovery operation because of such a vast range of possible places it could fall, according to the U.S. space agency.

But during a skip entry, Orion should be able to fly over 5,500 miles beyond the point it initially pokes into the upper air, giving the capsule more control over where it ultimately splashes down. NASA gets that extra wiggle room by bouncing back out of the atmosphere, where there is little drag on the spacecraft.

“One of the major advances with Artemis is that the spacecraft has the ability…to steer up and out of a denser part of the atmosphere, glide farther downrange or less downrange, so that you can pick the best landing site,” Edelen said.

NASA and Navy practicing a recovery operation for Orion
The U.S. Navy and NASA will work together to recover Artemis I’s Orion spacecraft after it splashes down in the Pacific Ocean on Dec. 11, 2022.
Credit: NASA / Tony Gray
Recovering Orion during a 2014 test
Orion is expected to return to Earth about 50 miles off the coast of San Diego, California.
Credit: NASA / Kim Shiflett

The goal is to drop Orion into the water closer to the U.S. coastline, allowing crews to get to weary returning astronauts quicker and reduce the number of boats, helicopters, and divers needed to get the job done.

Most Apollo moon missions concluded with re-entries into Earth’s atmosphere that put astronauts through the wringer of 6Gs, or six times the normal force of gravity. Apollo 16, the second to last crewed moon mission, had the highest G-level, tipping just over 7Gs.

If all goes according to plan, the three test dummies in Orion — Commander Moonikin Campos, Helga, and Zohar — will instead face two rounds of 4G-level forces. That’s a little more intense than what carnival-goers might experience on a spinning Gravitron, the superfast centrifuge ride that pins people against the wall with about 3.2 times the normal force of gravity.

Perhaps it’s a blessing the two female mannequins aren’t wearing helmets. As limbless torsos, they’d have a hard time hanging onto their hats.

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SpaceX launch marks 300th successful booster landing – Phys.org

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Credit: Unsplash/CC0 Public Domain

SpaceX sent up the 30th launch from the Space Coast for the year on the evening of April 23, a mission that also featured the company’s 300th successful booster recovery.

A Falcon 9 rocket carrying 23 of SpaceX’s Starlink internet satellites blasted off at 6:17 p.m. Eastern time from Cape Canaveral Space Force Station’s Space Launch Complex 40.

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The first-stage booster set a milestone of the 300th time a Falcon 9 or Falcon Heavy booster made a successful recovery landing, and the 270th time SpaceX has reflown a booster.

This particular booster made its ninth trip to space, a resume that includes one human spaceflight, Crew-6. It made its latest recovery landing downrange on the droneship Just Read the Instructions in the Atlantic Ocean.

The company’s first successful booster recovery came in December 2015, and it has not had a failed booster landing since February 2021.

The current record holder for flights flew 11 days ago making its 20th trip off the .

SpaceX has been responsible for all but two of the launches this year from either Kennedy Space Center or Cape Canaveral with United Launch Alliance having launched the other two.

SpaceX could knock out more launches before the end of the month, putting the Space Coast on pace to hit more than 90 by the end of the year, but the rate of launches by SpaceX is also set to pick up for the remainder of the year with some turnaround times at the Cape’s SLC-40 coming in less than three days.

That could amp up frequency so the Space Coast could surpass 100 launches before the end of the year, with the majority coming from SpaceX. It hosted 72 launches in 2023.

More launches from ULA are on tap as well, though, including the May 6 launch atop an Atlas V rocket of the Boeing CST-100 Starliner with a pair of NASA astronauts to the International Space Station.

ULA is also preparing for the second launch ever of its new Vulcan Centaur rocket, which recently received its second Blue Origin BE-4 engine and is just waiting on the payload, Sierra Space’s Dream Chaser spacecraft, to make its way to the Space Coast.

Blue Origin has its own it wants to launch this year as well, with New Glenn making its debut as early as September, according to SLD 45’s range manifest.

2024 Orlando Sentinel. Distributed by Tribune Content Agency, LLC.

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SpaceX launch marks 300th successful booster landing (2024, April 24)
retrieved 24 April 2024
from https://phys.org/news/2024-04-spacex-300th-successful-booster.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

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Wildlife Wednesday: loons are suffering as water clarity diminishes – Canadian Geographic

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The common loon, that icon of northern wilderness, is under threat from climate change due to declining water clarity. Published earlier this month in the journal Ecology, a study conducted by biologists from Chapman University and Rensselaer Polytechnic Institute in the U.S. has demonstrated the first clear evidence of an effect of climate change on this species whose distinct call is so tied to the soundscape of Canada’s lakes and wetlands.

Through the course of their research, the scientists found that July rainfall results in reduced July water clarify in loon territories in Northern Wisconsin. In turn, this makes it difficult for adult loons to find and capture their prey — mainly small fish — underwater, meaning they are unable to meet their chicks’ metabolic needs. Undernourished, the chicks face higher mortality rates. The consistent foraging techniques used by loons across their range means this impact is likely echoed wherever they are found — from Alaska to Canada to Iceland.

The researchers used Landsat imagery to find that there has been a 25-year consistent decline in water clarity, and during this period, body weights of adult loon and chicks alike have also declined. With July being the month of most rapid growth in young loons, the study also pinpointed water clarity in July as being the greatest predictor of loon body weight. 

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One explanation for why heavier rainfall leads to reduced water clarity is the rain might carry dissolved organic matter into lakes from adjacent streams and shoreline areas. Lawn fertilizers, pet waste and septic system leaks may also be to blame.

The researchers, led by Chapman University professor Walter Piper, hope to use these insights to further conservation efforts for this bird Piper describes as both “so beloved and so poorly understood.”

Return of the king

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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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