Connect with us

Science & Environment

Where will the UK bury nuclear waste for 100,000 years?

Published

on

Where will the UK bury nuclear waste for 100,000 years?


Kevin Church/BBC In Sellafield's fuel handling plant, nuclear fuel is moved by robotic arms that are controlled from behind metre-thick, lead-lined glassKevin Church/BBC

A repeating tone – blip, blip, blip – is the audible reminder that we are in one of the most hazardous nuclear sites in the world: Sellafield.

That sound – pulsing from speakers inside the cavernous fuel-handling plant – is a signal that everything is functioning as it should.

That is comforting because Sellafield, in Cumbria, is the temporary home to the vast majority of the UK’s radioactive nuclear waste, as well as the world’s largest stockpile of plutonium.

That waste is the product of reactions that drive the UK’s nuclear power stations and it is highly radioactive.

Advertisement

It releases energy that can penetrate and damage the cells in our bodies, and “it remains hazardous for 100,000 years”, explains Claire Corkhill, professor of radioactive waste management at University of Bristol.

Sellafield is filling up – and experts say we have no choice but to find somewhere new to keep this material safe.

Nuclear power is also part of the government’s stated mission for ”clean power by 2030”. More nuclear power means more nuclear waste.

A graphic shows how radioactive waste is produced when atoms of uranium are split in nuclear reactors

Inside Sellafield’s fuel-handling plant, we watch from behind one metre-thick, lead-lined glass as operators remotely control robotic arms.

They manoeuvre joysticks on what look like large retro game-controllers, as the arms pull used nuclear fuel rods – still glowing hot and highly radioactive – from the heavy metal containers in which they arrived.

Advertisement

This complex operation never stops. Sellafield runs 24 hours a day with 11,000 staff. It costs more than £2bn per year to keep the site going, and it comprises more than 1,000 buildings, connected by 25 miles of road.

Kevin Church/BBC A rod of spent nuclear fuel, seen from behind lead-lined protective glassKevin Church/BBC

The hot glow of rods of spent fuel is visible

However, in recent years, doubts have been raised about the site’s security and physical integrity.

One of its oldest waste storage silos is currently leaking radioactive liquid into the ground. That is a “recurrence of a historic leak” that Sellafield Ltd, the company that operates the site, says first started in the 1970s.

Sellafield has also faced questions about its working culture and adherence to safety rules. The company is currently awaiting sentencing after it pleaded guilty, in June, to charges related to cyber-security failings.

Advertisement

An investigation by the Guardian revealed that the site’s systems had been hacked, although the Office for Nuclear Regulation said there was “no evidence that any vulnerabilities had been exploited” by the hackers.

Getty Images A photograph of the Sellafield site  Getty Images

Sellafield costs more than £2bn per year to operate

All of this has cast a shadow over an operation that, as well as taking in newly created nuclear waste, also houses several decades worth of much older radioactive material.

The site no longer produces or reprocesses any nuclear material, but this is where the race began to produce plutonium for nuclear weapons at the height of the Cold War.

“It was the dawn of the nuclear age,” says Roddy Miller, Sellafield’s operations director. “But because it was a race, not a lot of thought was given to the long-term safe storage of the waste materials that were produced.”

Advertisement

The leaking storage silo, which was built in the 1960s, is just one of the buildings that now has to be emptied so the material inside can go into more modern silos. The building was only ever designed to be filled, and Sellafield says its plans to clear the site and demolish the building are the safest option.

The site’s head of retrievals, Alyson Armett, points out that without a “permanent solution” for the nuclear waste, the plans to decommission could be delayed.

The current plan for that permanent solution is to bury the waste deep underground.

A complicated search – both scientifically and politically – is currently on for somewhere to lock it away from humanity permanently.

Advertisement

“We need to isolate it from future populations or even civilisations, that’s the timescale we’re looking at,” says Prof Corkhill.

She studies how radioactive waste material can be made safe for extremely long-term storage, and is searching for the most stable, inert substance that nuclear waste could be “baked into”.

“We turn it into a solid – glass, ceramic or a material that’s just like the rocks that the uranium originally came from,” she explains. At Sellafield, the highest level of radioactive waste is stabilised in a similar way before it is stored on-site.

Kevin Church/BBC A nuclear materials researcher making glass in a laboratory Kevin Church/BBC

Scientists study how nuclear waste can be “baked” into solid, stable materials, like glass

The plan for permanent, underground storage is to contain that solid waste in a Russian doll-like series of barriers. The glass, encased in steel, will be shielded in concrete, then buried beneath the Earth‘s own barriers – layers of solid rock.

Advertisement

The question is, where will that facility be?

‘The waste is already here’

Six years ago, communities in England and Wales were asked to come forward if they were willing to consider having a disposal facility built near their town or village.

Potential sites will need the ideal geology – enough solid rock to create that permanent barrier. However, they also need something that might be more difficult – a willing community.

Advertisement

There are financial incentives for communities to take part in this discussion. So far, five have come forward. Two have already been ruled out. Allerdale in Cumbria was deemed unsuitable because there was not enough solid bedrock. Then, in September, councillors in South Holderness, in Yorkshire, withdrew after a series of local protests.

A graphic showing how nuclear waste disposal goes underground

Government scientists are assessing the remaining three communities that are currently in the running. Geologists have been carrying out seismic testing – looking for that all-important impermeable rock.

One of the communities being considered is very close to the Sellafield site in West Cumbria, at Seascale.

Local councillor David Moore says the industrial complex is “just down the road, and it’s the biggest employer in the area”.

He adds: “I think that’s why conversation here’s different. We’re already the hosts of the waste. And we all want to find it a safer location.

Advertisement

“I have seven grandchildren who live in this community, and I want them to live in a safe environment.”

Kate Stephens/BBC The beach at Seascale, where the nuclear site of Sellafield can be seen close to the coastal town  Kate Stephens/BBC

Sellafield is on the doorstep of the community at Seascale, on the Cumbrian coast

It is not yet clear if Mid Copeland, the area under consideration that includes Seascale, will have the right rock. The survey and consultation here – and in the other locations being considered – are in their early stages and scheduled to last at least a decade.

In the meantime, the conversation goes on and each community being considered for a geological disposal facility (GDF) now receives about £1m a year in investment while initial scientific tests are carried out.

Mr Moore is part of a committee called a GDF partnership. It includes local residents, local government and representatives of Nuclear Waste Services, which is the government body behind this project.

Advertisement

These partnerships aim to keep the process transparent and ensure local people are well-informed. They also decide how the money is spent.

Victoria Gill/BBC A geologist makes a presentation about ongoing investigations into finding a location for a nuclear waste disposal facility  Victoria Gill/BBC

Nuclear Waste Services host meetings to discuss the project with the local community

If a GDF is built here, Mr Moore says, there will be billions of pounds invested in the area. “If we’re going to host this on behalf of the UK, the community should benefit,” he says.

Also still on the shortlist are South Copeland, again on the Cumbrian coast, and a site on the east coast in Lincolnshire, where there have been a number of peaceful, but angry, protests.

On Halloween 2021 in Theddlethorpe, one of the local villages, several residents used their gardens to put up garish anti-nuclear dump scarecrows, inspired by an idea from pressure group the Guardians of the East Coast, which is campaigning against the disposal facility.

Advertisement

Ken Smith, from nearby Mablethorpe, is a member of both the campaign group and the local GDF partnership.

He thinks the government’s approach to finding a nuclear waste disposal site “stinks”.

Mr Smith is concerned that the voices of those most affected might not be heard and says it is unclear how local opinion will be measured at the end of the consultation.

The Department for Energy Security and Net Zero says a GDF will provide “safe and long-term disposal of the most hazardous radioactive waste”.

Advertisement

Prof Corkhill is convinced that a GDF is the safest solution. “We extract uranium from the rocks in the ground, we get energy from them and [this disposal facility essentially means] they’re returned back to the ground again,” she says.

“That uranium has been present in those rocks for billions of years. It’s been pushed and pulled, squeezed and heated, exposed to water and air. But the uranium is still safely locked up.”

Getty Images Two construction workers stand in a tunnel inside the underground  geological nuclear waste disposal facility in Finland Getty Images

In Finland, a geological facility has already been built

In Finland, a facility, called Onkalo, has already been built, and could receive its first nuclear waste within the next year.

Locations for three other sites around the world have also been chosen, in Switzerland, Sweden and France. They are at various stages of development.

Advertisement

In the UK, the search, studies and consultations continue. Only when those have been concluded and some kind of final assessment of community support, like a referendum, has taken place will construction of a GDF begin. The earliest that any waste could be put inside it is estimated to be during the 2050s.

Until then, it will continue to be stored and managed at Sellafield.

“We’ve benefited from nuclear energy in this country for 70 years, but we are still a long way behind cleaning up the legacy that has been left behind,” says Prof Corkhill.

“When we move to thinking about a new generation of nuclear power, we need to think about the waste now.”

Advertisement



Source link

Continue Reading
Advertisement
Click to comment

You must be logged in to post a comment Login

Leave a Reply

Science & Environment

Swarms of miniscule drones mimicking insects being tried for dangerous human tasks

Published

on

Swarms of miniscule drones mimicking insects being tried for dangerous human tasks


Dutch scientists have unveiled the country’s first laboratory to research how autonomous miniature drones can mimic insects to accomplish tasks ranging from finding gas leaks in factories to search-and-rescue missions. 

Called the Swarming Lab, researchers at the Delft University of Technology (TU Delft) say they aim to put a “self-flying” swarm of 100 tiny drones in the air, able to perform around the clock tasks.

Advertisement

This includes the drones landing by themselves on recharging pods and taking off again to continue flying — without humans ever having to get involved. 

“We are working not only to get these robots to be aware of one another, but also work together to complete complex tasks,” said Guido de Croon, a director at TU Delft’s Swarming Lab. 

Tasks include the tiny drones — with the same weight as a golf ball or an egg — “sniffing out” a gas leak in a factory.

A swarm of autonomous drones, fitted with sensors to detect the gas, will be able to fly autonomously around the factory until one drone detects traces of the gas.

Advertisement

It will then follow the “scent” of the gas while “calling” the other drones to help in the search using on-board sensors.

“In the same way, drone swarms can also be used to detect forest fires or continuously help in search and rescue operations over large areas,” De Croon said.

The scientists use studies on bee and ant swarms or how flocks of birds behave to try to program their drone swarms to do the same.

“Drone swarm technology is the idea that when we look at nature and you see many of these animals, like ants, that individually are perhaps not so smart but together they do … things that they could definitely not do by themselves,” De Croon said. “We want to instill the same capabilities also in robots,” De Croon said.

Advertisement

Doing this, the scientists look at how birds or insects swarm “using very simple behaviors.”

For instance, birds “look at their closest neighbors in the flock and they do things like ‘oh, I don’t want to be too close’ because they don’t want to collide,” De Croon said. But “I also don’t want to be the only one to be away from the flock.” 

They align with each other. And by following such simple rules you get these beautiful patterns that are very useful for the birds, also against predators,” he told AFP.

“So at that level, we draw inspiration and we try to make such simple rules also for robots but then for the applications we want to tackle.” 

Advertisement

But the scientists admit there are some challenges. 

“Swarms are complex systems,” De Croon said at a demonstration of the technology at the Swarming Lab, situated inside TU Delft’s Science Centre.”A single robot can do simple things within a swarm.” “It is actually quite difficult to predict, however, with these simple rules how a whole swarm will behave,” De Croon said.

The small size of the robots also hampers the amount of technology like sensors and on-board computing capacity the tiny drones can carry. 

Currently, the drones at the Swarming Lab still rely on an externally mounted camera to relay information to the buzzing beasts on their positions within the swarm. 

Advertisement

But the researchers have already developed the technology for robots to sense each other without external help. And they would n’t be the first: Scientists from Zhejiang University in China in 2022 successfully flew 10 autonomous drones through a thick bamboo forest.

Currently, the Swarming Lab, working with a start-up company of former TU Delft students called Emergent, has some 40 small drones involved in its research.

“The aim is eventually to put a swarm of around 100 drones in the air in the next five years,” said Lennart Bult, co-founder at Emergent. 

Ultimately “it would be really great if we actually get a bit closer to the astonishing intelligence of tiny creatures like honeybees,” said De Croon.

Advertisement



Source link

Advertisement
Continue Reading

Science & Environment

Ancient mummy with shrieking expression may have “died screaming from agony,” Egyptian researchers say

Published

on

Ancient mummy with shrieking expression may have "died screaming from agony," Egyptian researchers say


The mummy of an ancient Egyptian woman with her mouth wide open in what looks like an anguished shriek may have died “screaming from agony,” researchers say.

The unnamed woman mummy, discovered in a 1935 archeological expedition in Deir el-Bahari near Luxor, was kept in The Cairo Egyptian Museum and referred to as “Screaming Woman Mummy of the store of Kasr al Ainy.”

The face of the “Screaming Woman” mummy, discovered in 1935 near Luxor, is seen at the Egyptian Museum in Cairo, Egypt, January 18, 2023 in this handout photograph released on August 2, 2024.

Advertisement

Sahar Saleem


In an article in the journal Frontiers in Medicine, scientists said they used CT scans and other testing to examine whether the mummy had any pathological abnormalities and assess potential causes of death.

They found that the woman, who was around 48 years old at the time she died, had lost some teeth and lived with mild arthritis of the spine. Her body was embalmed about 3,500 years ago with high quality ingredients.

Ancient Egyptians mummified bodies because they believed preserving them after death secured a worthy existence in the afterlife. Usually, internal organs would be removed during the mummification process, but that did not take place with the “Screaming Woman.”

Advertisement

“In ancient Egypt, the embalmers took care of the dead body so it would look beautiful for the afterlife. That’s why they were keen to close the mouth of the dead by tying the jaw to the head to prevent the normal postmortem jaw drop,” lead researcher in the study, Cairo University radiology professor Sahar Saleem, told the Reuters news agency.

But this had not happened in the case of the “Screaming Woman.”

“This opened the way to other explanations of the widely opened mouth — that the woman died screaming from agony or pain and that the muscles of the face contracted to preserve this appearance at the time of death due to cadaveric spasm,” Saleem told Reuters, adding that, due to all of the unknowns around her history, the cause of her expression can’t be established with certainty.

Saleem told Reuters that cadaveric spasm is a poorly understood condition, where contracted muscles become rigid immediately after death.

Advertisement



Source link

Continue Reading

Science & Environment

Fossil discovery in Greenland ice sheet reveals increased risk of sea level rise

Published

on

Fossil discovery in Greenland ice sheet reveals increased risk of sea level rise


Greenland has melted before, and as the climate warms, it will melt again — this time leading to what scientists warn could be 20 to 25 feet of sea-level rise.

During one of the warm periods within the last 1.1 million years, the center, not just the edges, of Greenland’s massive ice sheet melted away, new research has found, giving way to a dry and barren “tundra landscape” that was home to various insects and plant life. The findings were shared in a new paper published today in the Proceedings of the National Academy of Sciences

When the ice sheet initially melted, there were lower levels of greenhouse gasses in the atmosphere than there are today. Now with more carbon dioxide in the atmosphere, scientists say Greenland’s ice sheet is more susceptible to melting than previously thought. 

Advertisement

“Greenland has been around for 2.7 million years with its ice,” said Paul Bierman, a scientist at the University of Vermont who co-led the new study. “Now there’s some evidence that this ice sheet is fragile.”

The researchers have been studying materials from beneath the hood of the Greenland ice sheet, the largest in the Northern hemisphere, since 2014. They examined sediment from the bottom of an ice core — dubbed GISP2 — extracted from two miles below the surface at the center of the ice sheet nearly 30 years ago. 

The 1-ounce sample of sediment was filled with clues of Greenland’s past. Tiny little black specks, when put under the microscope, revealed an insect eye, an Arctic poppy seed, parts of an Arctic willow, and tiny bits of soil fungus and spike moss — what Bierman referred to as a “frozen ecosystem underneath the ice.”

20x-noedf-dark-2.jpg
Willow bud scale, arctic poppy seed, fungal bodies, and rock spike moss megaspores found in the GISP2 soil sample viewed under a microscope.

Advertisement

Halley Mastro


According to researchers, the fossils provide “direct confirmation” that 90% of the ice sheet was once gone.

“Finding these fossils in the center of the ice sheet is unambiguous evidence that Greenland’s ice has disappeared [in the past],” said Bierman. “And once you lose the center of the ice sheet, you’ve lost it all.”

Advertisement

The findings supports what’s called the “fragile Greenland” hypothesis: that nature, outside of human influence, has caused the ice sheet to melt at least once since it formed, Bierman said. 

At 656,000 square miles, the Greenland ice sheet currently covers around 80% of the island territory. To put that into perspective, it’s about three times the size of Texas.

massey-gisp2dome-greenland90.jpg
Drill dome and camp for GISP2, in Summit Greenland.

Christine Massey

Advertisement


NASA, which has mapped Greenland’s ice loss, says the sheet has “rapidly declined in the last several years,” prompting the global sea level to rise around 0.03 inches per year. Greenland’s melting ice mass is now the No. 1 driver of sea level rise,  according to Bierman.

“In the early years of the climate warming, it was mountain glaciers that were doing most of the melting and adding water to the ocean,” he said. “Now it’s Greenland.”

While it could be a few thousand years before the entire Greenland mass melts, Bierman said, the consequences would be dire: hundreds of millions of people could lose their homes and businesses. Places we hold near and dear to our hearts would be lost.

“As I like to say when people ask me, why does it matter? I say think about your favorite beach. And then imagine your favorite beach with 25 feet of water on it,” Bierman said.

Advertisement

Advertisement



Source link

Continue Reading

Science & Environment

Discovery of “hobbit” fossils suggests tiny humans roamed Indonesian islands 700,000 years ago

Published

on

Discovery of "hobbit" fossils suggests tiny humans roamed Indonesian islands 700,000 years ago


Twenty years ago on an Indonesian island, scientists discovered fossils of an early human species that stood at about 3 1/2 feet tall, earning them the nickname “hobbits.”

Now a new study suggests ancestors of the hobbits were even slightly shorter.

“We did not expect that we would find smaller individuals from such an old site,” said Yousuke Kaifu, co-author of the study, which was published on Tuesday in the journal Nature. 

Advertisement

The original hobbit fossils date back to between 60,000 and 100,000 years ago. The new fossils were excavated at a site called Mata Menge, about 45 miles from the cave where the first hobbit remains were uncovered. The fossils were found on the top of a ribbon-shaped, pebbly sandstone layer in a small stream. They included exceptionally small teeth that possibly came from two individuals, researchers said. 

Hobbit Fossils
This image provided by Yousuke Kaifu shows an excavated arm bone fragment, left, next to the upper arm bone of an original “hobbit” that lived on the Indonesian island of Flores.

Yousuke Kaifu / AP


In 2016, researchers suspected the earlier relatives could be shorter than the hobbits after studying a jawbone and teeth collected from the new site. Further analysis of a tiny arm bone fragment and teeth suggests the ancestors were a mere 2.4 inches shorter and existed 700,000 years ago.

Advertisement

“They’ve convincingly shown that these were very small individuals,” said Dean Falk, an evolutionary anthropologist at Florida State University who was not involved with the research.

Researchers have debated how the hobbits — named Homo floresiensis after the remote Indonesian island of Flores — evolved to be so small and where they fall in the human evolutionary story. They’re thought to be among the last early human species to go extinct.

Hobbit Fossils
This photo provided by Gerrit van den Bergh shows the Mata Menge excavation site on the Indonesian island of Flores on Oct. 15, 2014.

Gerrit van den Bergh / AP

Advertisement


Scientists don’t yet know whether the hobbits shrank from an earlier, taller human species called Homo erectus that lived in the area, or from an even more primitive human predecessor. More research — and fossils — are needed to pin down the hobbits’ place in human evolution, said Matt Tocheri, an anthropologist at Canada’s Lakehead University.

“This question remains unanswered and will continue to be a focus of research for some time to come,” Tocheri, who was not involved with the research, said in an email.



Source link

Continue Reading

Science & Environment

NASA outlines backup plan to get Starliner crew back to Earth from International Space Station if Boeing ship can’t bring them home

Published

on

NASA outlines backup plan to get Starliner crew back to Earth from International Space Station if Boeing ship can't bring them home


As NASA debates the safety of Boeing’s Starliner spacecraft in the wake of multiple helium leaks and thruster issues, the agency is “getting more serious” about a backup plan to bring the ship’s two crew members back to Earth aboard a SpaceX Crew Dragon, officials said Wednesday.

In that case — and no final decisions have been made — Starliner commander Barry “Butch” Wilmore and co-pilot Sunita Williams would remain aboard the International Space Station for another six months and come down on a Crew Dragon that’s scheduled for launch Sept. 24 to carry long-duration crew members to the outpost.

starliner-nile.jpg
Boeing’s Starliner spacecraft docked to the forward port of the International Space Station as the lab complex approached Egypt and the Nile delta.

Advertisement

NASA


Two of the four “Crew 9” astronauts already assigned to the Crew Dragon flight would be bumped from the mission and the ship would be launched with two empty seats. Wilmore and Williams then would return to Earth next February with the two Crew 9 astronauts.

Shortly before the Crew Dragon launch, the Starliner would undock from the station’s forward port and return to Earth under computer control, without any astronauts aboard. The Crew Dragon then would dock at the vacated forward port.

Two earlier Starliner test flights were flown without crews and both landed successfully. The current Starliner’s computer system would need to be updated with fresh data files, and flight controllers would need to brush up on the procedures, but that work can be done in time to support a mid September return.

Advertisement

If that scenario plays out, Wilmore and Williams would end up spending 268 days — 8.8 months — in space instead of the week or so they planned when they blasted off atop a United Launch Alliance Atlas 5 rocket on June 5.

Based on uncertainty about the precise cause of the thruster problems, “I would say that our chances of an uncrewed Starliner return have increased a little bit based on where things have gone over the last week or two,” said Ken Bowersox, NASA’s director of space operations.

“That’s why we’re looking more closely at that option to make sure that we can handle it.”

But he cautioned that no final decisions will be made on when — or how — to bring the Starliner crew home until the agency completes a top-level flight readiness review.

Advertisement

No date has been set, but it could happen by late next week or the week after.

“Our prime option is to return Butch and Suni on Starliner,” said Steve Stich, manager of NASA’s Commercial Crew Program. “However, we have done the requisite planning to make sure we have other options open. We have been working with SpaceX to ensure that they’re ready to (return) Butch and Suni on Crew 9 if we need that.

“Now, we haven’t approved this plan (yet). We’ve done all the work to make sure this plan is there … but we have not turned that on formally. We wanted to make sure we had all that flexibility in place.”

Before the Starliner was launched, NASA and Boeing engineers knew about a small helium leak in the spacecraft’s propulsion system. After ground tests and analysis, the team concluded the ship could be safely launched as is.

Advertisement
071024-cft-crew2.jpg
Starliner co-pilot Suni Williams, left, and commander Barry “Butch” Wilmore, seen during a space-to-ground news conference last month. The two astronauts are now 63 days into a missions originally expected to last a little more than one week.

NASA


The day after launch, however, four more helium leaks developed and five aft-facing maneuvering thrusters failed to operate as expected. Ever since, NASA and Boeing have been carrying out data reviews and ground tests in an effort to understand exactly what caused both issues.

The Starliner uses pressurized helium to push propellants to the thrusters, which are critical to keeping the spacecraft properly oriented. That’s especially important during the de-orbit braking “burn” using larger rocket engines to slow the ship down for re-entry and an on-target landing.

Advertisement

To clear the Starliner for a piloted return to Earth, engineers must develop acceptable “flight rationale” based on test data and analyses that provides confidence the ship can make it through re-entry and landing with the required level of safety.

“The Boeing team (is) very confident that the vehicle could bring the crew home right now with the uncertainty we’ve got,” said Bowersox. “But we’ve got other folks that are probably a little more conservative. They’re worried that we don’t know for sure, so they estimate the risk higher and they would recommend that that we avoid coming home (on Starliner) because we have another option.

“So that’s a part of the discussion that we’re having right now. But again, I think both views are reasonable with the uncertainty band that we’ve got, and so our effort is trying to reduce that uncertainty.”

Boeing adamantly argues the Crew Dragon backup plan isn’t needed and that tests and analyses of helium leaks in the Starliner’s propulsion system and initial trouble with maneuvering thrusters show the spacecraft has more than enough margin to bring Wilmore and Williams safely back to Earth.

Advertisement

The helium leaks are understood, Boeing says, they have not gotten worse and more than enough of the pressurized gas is on board to push propellants to the thrusters needed to maneuver and stabilize the spacecraft through the critical de-orbit braking burn to drop out of orbit for re-entry and landing.

Likewise, engineers believe they now understand what caused a handful of aft-facing maneuvering jets to overheat and fire at lower-than-expected thrust during rendezvous with the space station, causing the Starliner’s flight computer to shut them down during approach.

Ground tests of a new Starliner thruster, fired hundreds of times under conditions that mimicked what those aboard the spacecraft experienced, replicated the overheating signature, which was likely caused by multiple firings during tests of the capsule’s manual control system during extended exposure to direct sunlight.

The higher-than-expected heating likely caused small seals in thruster valve “poppets” to deform and expand, the analysis indicates, which reduced the flow of propellant. The thrusters aboard the Starliner were test fired in space under more normal conditions and all operated properly, indicating the seals had returned to a less intrusive shape.

Advertisement

New procedures are in place to prevent the overheating that occurred during the rendezvous. Additional manual test firings have been ruled out, no extended exposure to the sun is planned and less frequent firings are required for station departure compared to rendezvous.

starliner-capsule-hangar.jpg
The Starliner capsule in Boeing’s processing facility at the Kennedy Space Center. The Service Module is the white lower section housing critical helium propellant pressurization tanks and plumbing along with maneuvering thrusters in four rectangular engine pods, or “doghouses,” spaced around the exterior.

William Harwood/CBS News


In a statement Wednesday, Boeing said, “We still believe in Starliner’s capability and its flight rationale. If NASA decides to change the mission, we will take the actions necessary to configure Starliner for an uncrewed return.”

Advertisement

The helium plumbing and thrusters are housed in the Starliner’s service module, which will be jettisoned to burn up in the atmosphere before the crew capsule re-enters for landing. As such, engineers will never be able to examine the hardware first hand to prove, with certainty, what went wrong.

At this point, that uncertainty appears to support bringing Wilmore and Williams back to Earth aboard the Crew Dragon. But it’s not yet a certainty.

“If we could replicate the physics in some offline testing to understand why this poppet is heating up and extruding and then why it’s contracting, that would give us additional confidence to move forward, to return Butch and Sonny on this vehicle,” Stich said.

“That’s what the team is really striving to do, to try to look at all the data and see if we can get a good physical explanation of what’s happening.”

Advertisement

In the meantime, the wait for a decision, one way or the other, drags on.

“In the end, somebody – some one person – designated to be the decision maker, that person has to come to a conclusion,” Wayne Hale, a former shuttle flight director and program manager, wrote in a blog post earlier this week.

“The engineers will always always always ask for more tests, more analysis, more time to get more information to be more certain of their conclusions. The decider also has to decide when enough has been done. The rub in all of this … is that it always involves the risk to human life.”

Hale concluded his post by saying: “I do not envy today’s decision makers, the ones weighing flight rationale. My only advice is to listen thoroughly, question effectively, ask for more data when necessary. But when it is time, a decision must be made.”

Advertisement

Advertisement



Source link

Continue Reading

Science & Environment

Drones setting a new standard in ocean rescue technology

Published

on

Drones setting a new standard in ocean rescue technology


Last month, two young paddleboarders found themselves stranded in the ocean, pushed 2,000 feet from the shore by strong winds and currents. Thanks to the deployment of a drone, rescuers kept an eye on them the whole time and safely brought them aboard a rescue boat within minutes.

In North Carolina, the Oak Island Fire Department is one of a few in the country using drone technology for ocean rescues. Firefighter-turned-drone pilot Sean Barry explained the drone’s capabilities as it was demonstrated on a windy day. 

“This drone is capable of flying in all types of weather and environments,” Barry said. 

Advertisement

Equipped with a camera that can switch between modes — including infrared to spot people in distress — responders can communicate instructions through a speaker. It also can carry life-preserving equipment.

The device is activated by a CO2 cartridge when it comes in contact with water. Once triggered, it inflates into a long tube, approximately 26 inches long, providing distressed swimmers something to hold on to.

In a real-life rescue, after a 911 call from shore, the drone spotted a swimmer in distress. It released two floating tubes, providing the swimmer with buoyancy until help arrived.

Like many coastal communities, Oak Island’s population can swell from about 10,000 to 50,000 during the summer tourist season. Riptides, which are hard to detect on the surface, can happen at any time.

Advertisement

Every year, about 100 people die due to rip currents on U.S. beaches. More than 80% of beach rescues involve rip currents, if you’re caught in one, rescuers advise to not panic or try to fight it, but try to float or swim parallel to the coastline to get out of the current.

Oak Island Fire Chief Lee Price noted that many people underestimate the force of rip currents.

“People are, ‘Oh, I’m a good swimmer. I’m gonna go out there,’ and then they get in trouble,” Price said.

For Price, the benefit of drones isn’t just faster response times but also keeping rescuers safe. Through the camera and speaker, they can determine if someone isn’t in distress.

Advertisement

Price said many people might not be aware of it. 

“It’s like anything as technology advances, it takes a little bit for everybody to catch up and get used to it,” said Price.

In a demonstration, Barry showed how the drone can bring a safety rope to a swimmer while rescuers prepare to pull the swimmer to shore.

“The speed and accuracy that this gives you … rapid deployment, speed, accuracy, and safety overall,” Price said. “Not just safety for the victim, but safety for our responders.”

Advertisement

Advertisement



Source link

Continue Reading

Trending

Copyright © 2017 Zox News Theme. Theme by MVP Themes, powered by WordPress.