Sunday, September 29, 2024

SPACE/COSMOLOGY

SpaceX launches rescue mission for two NASA astronauts stranded at the ISS

SpaceX on Saturday launched a mission to rescue two astronauts stuck on the International Space Station (ISS), though the return leg of the mission to bring the two home will not be completed until next year. The two test pilots were marooned on the ISS when their Boeing spacecraft returned to Earth empty earlier this month because of safety concerns
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Issued on: 28/09/2024 - 
SpaceX's Falcon 9 rocket lifts off from Cape Canaveral, Florida, en route to the International Space Station on September 28, 2024. 
© Miguel Rodriguez Carrill, Getty Images via AFP

SpaceX launched a rescue mission for the two stuck astronauts at the International Space Station on Saturday, sending up a downsized crew to bring them home but not until next year.

The capsule rocketed toward orbit to fetch the test pilots whose Boeing spacecraft returned to Earth empty earlier this month because of safety concerns. The switch in rides left it to NASA’s Nick Hague and Russia’s Alexander Gorbunov to retrieve Butch Wilmore and Suni Williams.

Since NASA rotates space station crews approximately every six months, this newly launched flight with two empty seats reserved for Wilmore and Williams won’t return until late February. Officials said there wasn’t a way to bring them back earlier on SpaceX without interrupting other scheduled missions.

By the time they return, the pair will have logged more than eight months in space. They expected to be gone just a week when they signed up for Boeing’s first astronaut flight that launched in June.

NASA ultimately decided that Boeing’s Starliner was too risky after a cascade of thruster troubles and helium leaks marred its trip to the orbiting complex. The space agency cut two astronauts from this SpaceX launch to make room on the return leg for Wilmore and Williams.


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Williams has since been promoted to commander of the space station, which will soon be back to its normal population of seven. Once Hague and Gorbunov arrive this weekend, four astronauts living there since March can leave in their own SpaceX capsule. Their homecoming was delayed a month by Starliner’s turmoil.

Hague noted before the flight that change is the one constant in human spaceflight.

“There’s always something that is changing. Maybe this time it’s been a little more visible to the public,” he said.

Hague was thrust into the commander’s job for the rescue mission based on his experience and handling of a launch emergency six years ago. The Russian rocket failed shortly after liftoff, and the capsule carrying him and a cosmonaut catapulted off the top to safety.

Rookie NASA astronaut Zena Cardman and veteran space flier Stephanie Wilson were pulled from this flight after NASA opted to go with SpaceX to bring the stuck astronauts home. The space agency said both would be eligible to fly on future missions. Gorbunov remained under an exchange agreement between NASA and the Russian Space Agency.

“I don’t know exactly when my launch to space will be, but I know that I will get there,” Cardman said from NASA’s Kennedy Space Center, where she took part in the launch livestream.

Hague acknowledged the challenges of launching with half a crew and returning with two astronauts trained on another spacecraft.

“We’ve got a dynamic challenge ahead of us,” Hague said after arriving from Houston last weekend. “We know each other and we’re professionals and we step up and do what’s asked of us.”

SpaceX has long been the leader in NASA’s commercial crew program, established as the space shuttles were retiring more than a decade ago. SpaceX beat Boeing in delivering astronauts to the space station in 2020 and it’s now up to 10 crew flights for NASA.

Boeing has struggled with a variety of issues over the years, repeating a Starliner test flight with no one on board after the first one veered off course. The Starliner that left Wilmore and Williams in space landed without any issues in the New Mexico desert on Sept. 6, and has since returned to Kennedy Space Center. A week ago, Boeing’s defense and space chief was replaced.

Delayed by Hurricane Helene pounding Florida, the latest SpaceX liftoff marked the first for astronauts from Launch Complex 40 at Cape Canaveral Space Force Station. SpaceX took over the old Titan rocket pad nearly two decades ago and used it for satellite launches, while flying crews from Kennedy’s former Apollo and shuttle pad next door. The company wanted more flexibility as more Falcon rockets soared.

(AP)

Space travel might be harmful for human hearts

By Dennis Thompson, HealthDay News


Long-term space travel to Mars could be bad for astronauts' hearts, a new zero-gravity study shows. Photo by Adobe Stock/HealthDay News

Long-term space travel to Mars could be bad for astronauts' hearts, a new zero-gravity study shows.

After a month at the International Space Station, a set of 48 bioengineered human heart tissue samples beat about half as strong as similar tissues that remained on Earth.

The tissues also became weaker and started showing genetic evidence of inflammation and oxidative damage that are hallmarks of heart disease, researchers reported Monday in the Proceedings of the National Academy of Sciences.

"Many of these markers of oxidative damage and inflammation are consistently demonstrated in post-flight checks of astronauts," added researcher Devin Mair, a postdoctoral fellow at Johns Hopkins Medicine in Baltimore.

Previous studies have shown that some astronauts return to Earth with reduced heart muscle function and irregular heartbeats, researchers said. Some, but not all, of these effects dissipate over time following their return.

Missions to Mars could mean as much as two years spent in space, making it crucial that doctors better understand the effects of weightlessness on heart function, researchers said.

For the study, researchers used stem cells to create a set of heart muscle cells, called cardiomyocytes.

The team then placed the heart muscle tissues into a chip that strings the tissues between two posts, to collect data about how the tissues beat. The resulting chambers were about half the size of a cell phone.

"An incredible amount of cutting-edge technology in the areas of stem cell and tissue engineering, biosensors and bioelectronics, and micro-fabrication went into ensuring the viability of these tissues in space," said project leader Deok-Ho Kim, a professor of biomedical engineering and medicine at Johns Hopkins Medicine.

A SpaceX mission took the heart tissues into space in March 2020. Once they safely reached the space station, scientists received real-time data for 10 seconds every half-hour about the cells' strength of contraction and beating patterns.

Astronaut Jessica Meir changed the liquid nutrients surrounding the tissues once a week, and preserved tissues for later genetic and imaging analysis.

When the tissue chambers returned to earth, researchers continued to track their progress. They also were compared to tissues developed from the same source and maintained in an Earthbound laboratory.


The heart muscle tissues in space became weaker, and also developed irregular beating, researchers said.

The tissues developed a delay between beats about five times longer that the normal delay of around a second, researchers said. The time between beats returned nearly to normal following their return to Earth.

The protein bundles in muscle cells that help them contract, called sarcomeres, also became shorter and more disordered in the space-bound heart tissue samples. This is a hallmark of human heart disease, researchers noted.

Other abnormalities developed in the energy-producing mitochondria in the tissue samples, as well as in genetic markers for inflammation and oxidative damage.

A second batch of bioengineered heart tissue samples went to the space station in 2023 to test drugs that may protect them from the effects of low gravity. That study is ongoing, researchers said.

The researchers also continue to improve their heart tissue chip system, and are studying the effects of space radiation on human heart tissues.

More information

NASA has more on the human body in space.

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