Science & Technology

Scientists document how space travel messes with the human brain

Published

4 months ago

June 9, 2023

(Last Updated On: June 9, 2023)

Space can be an unfriendly place for the human body, with microgravity conditions and other factors tampering with our physiology, from head to toe – head, of course, being a primary concern.

A new NASA-funded study provides a deeper understanding of the issue. Researchers said on Thursday that astronauts who traveled on the International Space Station (ISS) or NASA space shuttles on missions lasting at least six months experienced significant expansion of the cerebral ventricles – spaces in the middle of the brain containing cerebrospinal fluid, Reuters reported.

This colorless and watery fluid flows in and around the brain and spinal cord. It cushions the brain to help protect against sudden impact and removes waste products.

Based on brain scans of 30 astronauts, the researchers found that it took three years for the ventricles to fully recover after such journeys, suggesting that an interval of at least that duration would be advisable between longer space missions.

“If the ventricles don’t have sufficient time to recover between back-to-back missions, this may impact the brain’s ability to cope with fluid shifts in microgravity. For example, if the ventricles are already enlarged from a previous mission, they may be less compliant and/or have less space to expand and accommodate fluid shifts during the next mission,” said University of Florida neuroscientist Heather McGregor, lead author of the study published in the journal Scientific Reports.

Age-related ventricular enlargement – caused not by microgravity but by brain atrophy – can be associated with cognitive decline.

“The impact of ventricular expansion in space travelers is not currently known. More long-term health follow-up is needed. This ventricular expansion likely compresses the surrounding brain tissue,” University of Florida applied physiology and kinesiology professor and study senior author Rachael Seidler said.

The absence of Earth’s gravity modifies the brain.

“This seems to be a mechanical effect,” Seidler said. “On Earth, our vascular systems have valves that prevent all of our fluids from pooling at our feet due to gravity. In microgravity, the opposite occurs – fluids shift toward the head. This headward fluid shift likely results in ventricular expansion, and the brain sits higher within the skull.”

The study involved 23 male and seven female astronauts – average age around 47 – from the U.S., Canadian and European space agencies. Eight traveled on space shuttle missions of about two weeks. Eighteen were on ISS missions of about six months and four on ISS missions of about a year.

Little to no ventricular volume change occurred in astronauts after short missions. Enlargement occurred in astronauts after missions of six months or longer, though there was no difference in those who flew for six months compared to those who did so for a year.

“This suggests that the majority of ventricle enlargement happens during the first six months in space, then begins to taper off around the one-year mark,” McGregor said.

The fact that enlargement did not worsen after six months could be good news for future Mars missions on which astronauts may spend two years in microgravity during the journey.

“This preliminary finding is promising for astronaut brain health during long-duration missions, but it’s still important that we examine MRI data from a larger group of astronauts and following even longer missions,” McGregor said.

The absence of enlargement following short flights was good news for people who may consider short space tourism jaunts, Seidler added, as that industry develops.

Microgravity conditions also cause other physiological effects due to the reduced physical load on the human body. These include bone and muscle atrophy, cardiovascular changes, issues with the balance system in the inner ear and a syndrome involving the eyes. Elevated cancer risk from the greater exposure to solar radiation that astronauts may encounter the further they travel from Earth is another concern.

Related Topics:#Brain #ISS #Science featured humans Space

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Three astronauts return to Earth after a year in space

Published

4 days ago

September 29, 2023

Ariana News

(Last Updated On: September 29, 2023)

A NASA astronaut and two Russian cosmonauts returned to Earth on Wednesday after being stuck in space for just over a year. American Frank Rubio set a record for the longest U.S. spaceflight — a result of the extended stay.

The trio landed in a remote area of Kazakhstan, descending in a Soyuz capsule that was rushed up as a replacement after their original ride was hit by space junk and lost all its coolant while docked to the International Space Station, AP reported.

What should have been a 180-day mission turned into a 371-day stay. Rubio spent more than two weeks longer in space than Mark Vande Hei, who held NASA’s previous endurance record for a single spaceflight.
The Soyuz capsule that brought Rubio and cosmonauts Sergey Prokopyev and Dmitri Petelin back was a replacement launched in February. Russian engineers suspect a piece of space junk pierced the radiator of their original capsule late last year, midway through what should have been a six-month mission. Engineers worried that without cooling, the capsule’s electronics and any occupants could overheat to dangerous levels, so the craft returned empty.

There wasn’t another Soyuz to launch a fresh crew until this month. Their replacements finally arrived nearly two weeks ago.

“No one deserves to go home to their families more than you,” the space station’s new commander, Denmark’s Andreas Mogensen, said earlier this week.
Prokopyev told ground controllers throughout the descent that all three were feeling good. They experienced more than four times the force of gravity as their capsule streaked through the atmosphere and came to a touchdown in the barren Kazakh steppes, ending up on its side. Helicopters moved in with recovery crews to fetch the astronauts.

“It’s good to be home,” Rubio said after being pulled from the capsule.

Rubio, 47, an Army doctor and helicopter pilot, said at a news conference last week that he never would have agreed to a full year in space if asked at the outset. He ended up missing important family milestones including the oldest of his four children finishing her first year at the U.S. Naval Academy and another heading off to West Point.

Rubio had said the psychological aspect of spending so long in space was tougher than he expected. He may hold on to this record for a while. NASA has no plans as of now for more yearlong missions.

It was the first spaceflight for Rubio and Petelin, 40, an engineer. Prokopyev, 48, an engineer and pilot, has now pulled two long station stints.
They logged 157 million miles (253 million kilometers) since launching from Kazakhstan last September and circled the world nearly 6,000 times.

Science & Technology

NASA’s first asteroid sample on track for Sunday parachute landing in Utah

Published

1 week ago

September 23, 2023

Ariana News

(Last Updated On: September 23, 2023)

A NASA space capsule carrying a sample of rocky material plucked from the surface of an asteroid three years ago hurtled toward Earth this weekend headed for a fiery plunge through the atmosphere and a parachute landing in the Utah desert on Sunday.

Weather forecasts were favorable and the robotic spacecraft OSIRIS-REx was on course to release the sample-return capsule for final descent as planned, with no further adjustments to its flight path needed, NASA officials said at a news briefing on Friday, Reuters reported.

Mission managers are expecting a “spot-on” touchdown on the U.S. military’s vast Utah Test and Training range, west of Salt Lake City, said Sandra Freund, program manager at Lockheed Martin, which designed and built the spacecraft.

The round, gumdrop-shaped capsule is scheduled to land by parachute at 10:55 a.m. EDT (1455 GMT), about 13 minutes after streaking into the top of the atmosphere at roughly 35 times the speed of sound, capping a seven-year voyage.

If successful, the OSIRIS-REx mission, a joint effort between NASA and scientists at the University of Arizona, would mark the third asteroid sample, and by far the largest, ever returned to Earth for analysis, following two similar missions by Japan’s space agency over the past 13 years.

OSIRIS-REx collected its specimen from Bennu, a carbon-rich asteroid discovered in 1999 and classified as a “near-Earth object” because it passes relatively close to our planet every six years. Scientists put the odds of it striking Earth at 1-in-2,700 in the late 22nd century.

Bennu is small as asteroids go, measuring just 1,600 feet (500 meters) in diameter – slightly wider than the Empire State Building is tall but tiny compared with the cataclysmic Chicxulub asteroid that struck Earth some 66 million years ago, wiping out the dinasours.

Like other asteroids, Bennu is a primordial relic of the early solar system whose present-day chemistry and mineralogy are virtually unchanged since it formed some 4.5 billion years ago. It thus holds valuable clues to the origins and development of rocky planets such as Earth, and may even contain organic molecules similar to those necessary for life to evolve.

“We’re literally looking at geologic materials that formed before Earth even existed,” Dante Lauretta, principal investigator for the mission at the University of Arizona, Tucson, told reporters last month.

OSIRIS-REx launched in September 2016 and reached Bennu in 2018, then spent nearly two years orbiting the asteroid before venturing close enough to sink its robot arm into the loose surface on Oct. 20, 2020, in a grab-and-go maneuver.

The spacecraft embarked on a 1.2-billion-mile cruise back to Earth in May 2021.

The Bennu sample is estimated at 250 grams (8.8 ounces), far surpassing the amount of material carried back from asteroid Ryugu in 2020 and asteroid Itokawa in 2010.

On arrival, the new sample will be flown by helicopter to a “clean room” set up at the Utah test range for initial examination, then transported to NASA’s Johnson Space Center in Houston, to be parceled into smaller specimens promised to some 200 scientists in 60 laboratories around the world.

The main portion of the OSIRIS-REx spacecraft, meanwhile, is expected to sail on to explore yet another near-Earth asteroid.

Science & Technology

Explainer: What to know about October’s ‘ring of fire’ solar eclipse

Published

2 weeks ago

September 22, 2023

Ariana News

(Last Updated On: September 22, 2023)

Millions of people in the Americas will be in a position to witness an astronomical treat on Oct. 14 with a solar eclipse in which – weather permitting – the moon will be seen passing in front of the sun.

The eclipse is due to be visible along a path covering parts of the United States, Mexico and several countries in Central America and South America, Reuters reported.

Here is an explanation of the type of solar eclipse that will occur and where it will be visible.

WHAT IS AN ANNULAR SOLAR ECLIPSE?

A solar eclipse happens when the moon journeys between Earth and the sun, blocking the view along a small path of Earth of some or all of the sun’s face as it passes. The one that will occur on Oct. 14 is a type called an “annular solar eclipse.” This occurs when the moon passes between Earth and the sun at a time when the moon is at or close to its farthest point from our planet. It does not completely obscure the face of the sun, unlike in a total solar eclipse.

WHY DOES IT LOOK LIKE A RING OF FIRE?

Because the moon is farther than usual from Earth during an annular solar eclipse, the moon will not completely obscure the sun, instead looking like a dark disk superimposed atop the sun’s larger, bright face in the sky. As a result, the eclipse will momentarily look like a ring of fire surrounding the dark disc of the moon. A total solar eclipse is due to occur on April 8, 2024, passing over Mexico, the United States and Canada.

WHERE WILL IT BE VISIBLE AND WHAT IS ITS PATH?

According to the U.S. space agency NASA, the path in the United States where the maximum obscuring of the sun will occur on Oct. 14 runs through parts of several states beginning at 9:13 a.m. PDT (12:13 p.m. EDT/1613 GMT) in Oregon, then California, Nevada, Utah, Arizona, New Mexico and Texas. The path then crosses over parts of Mexico, Guatemala, Belize, Honduras, Nicaragua, Panama, Colombia and Brazil before ending at sunset in the Atlantic Ocean. People in much larger parts of North America, Central America and South America will be able to see lesser obscuring of the sun – still an impressive sight.

HOW BIG ARE THE EARTH, MOON AND SUN?

The moon will nearly cover the sun’s face, as visible from Earth, only because the moon – in actuality much smaller than the sun – is so much closer to our planet. The moon’s diameter is 2,159 miles (3,476 km), compared to the sun’s diameter of about 865,000 miles (1.4 million km) and Earth’s diameter of 7,918 miles (12,742 km).

WHAT IS THE SAFEST WAY TO WATCH AN ECLIPSE?

Experts warn that it is unsafe to look directly at the bright sun without using specialized eye protection designed for solar viewing, risking eye injury. Because the sun is never fully blocked by the moon in an annular solar eclipse, it is never safe to look directly at it without such eye protection. Viewing it through a camera lens, binoculars or telescope without making use of a special-purpose solar filter can cause severe eye injury, according to these experts. They advise using safe solar viewing glasses or a safe handheld solar viewer at all times during an annular solar eclipse, noting that regular sunglasses are not safe for viewing the sun.

HOW DO SOLAR ECLIPSES DIFFER FROM LUNAR ECLIPSES?

Lunar eclipses occur when Earth is positioned between the moon and the sun and our planet’s shadow is cast upon the lunar surface. This leaves the moon looking dim from Earth, sometimes with a reddish color. Lunar eclipses are visible from half of Earth, a much wide area than solar eclipses.