Connect with us

Science

NASA clears SpaceX crew capsule for first astronaut mission – Spaceflight Now

Published

on


The Falcon 9 rocket that will carry astronauts Doug Hurley and Bob Behnken into orbit fired its engines in a ground test at 4:33 p.m. EDT (2033 GMT) on Friday, May 22. Credit: Stephen Clark / Spaceflight Now

After a two-day readiness review, NASA managers gave a green light Friday for SpaceX to proceed with final preparations for launch next Wednesday, May 27, of a commercial spaceship carrying astronauts Doug Hurley and Bob Behnken to the International Space Station on the first orbital spaceflight from U.S. soil since 2011.

Hours later, SpaceX test-fired the 215-foot-tall (65-meter) Falcon 9 rocket that will boost Hurley and Behnken into orbit aboard the company’s Crew Dragon spacecraft.

The Flight Readiness Review’s conclusion Friday kicked off a busy Memorial Day weekend at the Kennedy Space Center. The Dragon astronauts will put on in their SpaceX-made flight suits Saturday and ride in a Tesla Model X automobile to launch pad 39A, where the Falcon 9 and Crew Dragon capsule were placed on their seaside launch mount Thursday.

Hurley and Behnken — both veterans of two space shuttle flights — will climb aboard the Dragon capsule with the help of about a half-dozen SpaceX crew technicians, practicing the steps they will take on launch day.

On Monday, SpaceX will convene a Launch Readiness Review to go over data and results from the test-firing Friday and the crew dress rehearsal Saturday. If all looks good, preparations will proceed toward launch of the first orbital crewed mission from the Kennedy Space Center in nearly nine years at 4:33 p.m. EDT (2033 GMT) Wednesday.

Assuming the mission takes off Wednesday, the Crew Dragon is scheduled to glide to an automated docking with the International Space Station around 11:40 a.m. EDT (1540 GMT) Thursday. Hurley and Behnken are slated to spend one-to-hour months on the orbiting research outpost before coming back to Earth for a parachute-assisted splashdown in the Atlantic Ocean.

The Flight Readiness Review began Thursday and ran into overtime Friday. NASA officials anticipated ahead of time that might happen, given the volume of data to discuss for the first crewed flight on a brand new spacecraft design.

“We had a very successful Flight Readiness Review, in that we did thorough review of all fo the systems and all the risks,” said Steve Jurczyk, NASA’s associate administrator, who chaired the review meeting. “And it was unanimous on the board that we are go for launch.

“It is really exciting to be launching American astronauts on American rockets from American soil — from Kennedy Space Center — for the first time in nine years,” Jurczyk said in a press conference Friday. “I know it’s been a long, really challenging road, and I just cannot say how proud I am of the NASA-SpaceX team for all their talent, hard work, dedication and perseverance to get to this point of five days from launch.”

“Today, we got a go to launch, but really it’s a go for the mission,” said Benji Reed, SpaceX’s director of crew mission management. “There will be lots more data, lots more reviews in the next few days. There will be constant vigilance and watching of the data and observations. As we go through the mission, there will be other reviews and conversations to make sure we’re go for each aspect, including go to come home.”

NASA managers received briefings from agency and SpaceX engineers during the Flight Readiness Review, including presentations on topics that garnered widespread attention over the last year, such as the Crew Dragon’s parachutes and an abort propulsion system problem that led to the explosion of a capsule during a ground test in April 2019.

“We established a little while ago that the original chute design did not have adequate margin, based on some knowledge we had gained through testing of how the chutes deploy, and the loading on the chutes,” Jurczyk said. “So SpaceX stepped up and did a new chute design, and we had to qualify that new chute design to higher margins than we had the previous chutes.

“The NASA-SpaceX team did an amazing job laying out a test program and executing that test program,” Jurczyk said. “However, it’s fewer tests than we normally would see on a parachute qualification program. So we took a long time in a couple of presentations during the review to have the team walk us through the design, the changes, the qualification testing, and the margins on the chute to make sure that everybody was good with how those chutes were qualified. And we had very high confidence that they will function as we need them to when Bob and Doug return from the International Space Station.

The Crew Dragon uses a series of pilot and drogue chutes during descent, then unfurls four main parachutes to brake for splashdown. At the end of a typical mission, the Crew Dragon spacecraft will splash down in the Atlantic Ocean around 24 nautical miles off the coast of Cape Canaveral.

The capsule’s abort system was also a topic of extended discussion during the Flight Readiness Review. In the event of a major problem during fueling of the Falcon 9 rocket, or a launch failure during the vehicle’s climb into orbit, the Crew Dragon can fire eight SuperDraco engines to push the capsule off the launch vehicle and propel the astronauts to safety.

The SuperDracos consume a high-pressure mix of hydrazine fuel and nitrogen tetroxide oxidizer. A Dragon spacecraft that completed an unpiloted test flight to the space station in March 2019 was destroyed during a ground test-firing of the SuperDraco engines last April at Cape Canaveral.

Investigators traced the cause of the explosion to a leaky valve inside the capsule’s high-pressure abort propulsion system. The leak allowed nitrogen tetroxide to leak into the propulsion system’s helium pressurization lines, which are designed to rapidly prime the SuperDraco thrusters to fire up in quick response to a launch emergency.

As the pressurization system activated during the ground test last year, a slug of nitrogen tetroxide was forced back into the faulty titanium valve, triggering an explosion. Experts spent months studying the physics of the accident, and learned new information about how titanium components used in aerospace vehicles might ignite under certain conditions.

SpaceX replaced the suspect valve in future Crew Dragon spacecraft with a single-use burst disk designed to rupture during activation of the SuperDraco abort thrusters, which would only occur during a launch failure.

The fix was tested during a second ground firing in November, then again during a high-altitude launch escape test in January over the Atlantic Ocean.

“Last April, I probably wasn’t thinking I was going to be flying (crew) in a year, but you can never sell this NASA and SpaceX team short,” said Kathy Lueders, managers of NASA’s commercial crew program. “They have always accomplished miracles for me, and I’m very, very proud of them right now.”

Jurczyk said NASA officials also discussed a recent “performance shortfall” during a test of the Crew Dragon’s internal fire suppression system.

“That’s a system tat suppresses any fire or any equipment underneath the floor of Dragon,” Jurczyk said. “The team … analyzed both the hazards there, as well as the ability to suppress a fire, and we’ve deemed the risk to be very low there.”

Jurczyk took the place of Doug Loverro, the former head of NASA’s human spaceflight directorate, for this week’s Flight Readiness Review. Loverro, who was due to chair the FRR, abruptly resigned effective Monday, May 18.

In a letter to NASA employees, Loverro wrote that he resigned due to a “mistake” he made earlier this year. Multiple sources said Loverro violated a procurement rule during a competition to select contractors for NASA’s Human Landing System for the Artemis program, which aims to develop crewed moon landing vehicles to carry astronauts to the lunar surface.

Jurczyk, NASA’s most senior career civil servant, stepped into the role as chair of the Flight Readiness Review.

The Crew Dragon’s debut flight with astronauts has been nearly a decade in the making. NASA first awarded SpaceX funding to work on a human-rated spacecraft in 2011.

Funded and led by billionaire Elon Musk, SpaceX has won a series of NASA contracts and funding agreements over the last nine years for work on the Crew Dragon project. To date, NASA has agreed to pay SpaceX more than $3.1 billion to develop the Crew Dragon, and then fly at least six operational crew rotation missions to the space station.

NASA also awarded Boeing a similar series of contracts for development and flights of the Starliner crew capsule. The Starliner’s first test mission without a crew ended prematurely in December without reaching the space station, and Boeing will re-fly the unpiloted demonstration mission later this year before the Starliner is cleared for its first launch with astronauts.

The first operational Crew Dragon flight will follow the test flight set for launch next week, which is officially designated Demo-2, or DM-2. It follows the first Crew Dragon test flight to the space station last year, which did not carry any astronauts on-board.

SpaceX has also completed two major tests of the Crew Dragon’s launch abort system — a pad abort in 2015 and the in-flight escape demonstration in January.

Kathy Lueders, manager of NASA’s commercial crew program, signs a human rating certification package during Thursday during the first day of a Flight Readiness Review for the Crew Dragon Demo-2 test flight. Credit: NASA/Kim Shiflett

According to Jurczyk, this week’s FRR doubled as an “interim human-rating certification review” for SpaceX’s Crew Dragon spacecraft.

“What I mean by interim is that we’ve validated that this system meets the human-rating certification requirements for the Demo-2 mission, and those requirements feed forward to future missions, including the Crew-1 mission (the Dragon’s first operational crew rotation flight),” Jurczyk said. “We will have a final human-rating certification review after Demo-2 and before the Crew-1 mission, just to certify the relatively small set of design changes between the Demo-2 system and the Crew-1 system. And at that point, we’ll deem the system human-rating certified.”

NASA also determined the Crew Dragon meets the agency’s risk requirements for the commercial crew program. When NASA established requirements for the new commercial crew spaceships, agency officials set the program’s safety threshold at 1-in-270 odds of an accident during a 210-day mission that would kill the astronauts on-board

Lueders said Friday that SpaceX meets that risk requirement, with the help of advanced design modeling and inspections to guard against the threat of micrometeoroids and orbital debris while docked at the space station.

But determining the loss of crew, or LOC, probability for any given flight is tricky. The number hinges on a number of factors, including numerical and statistical inputs, many of which are grounded in assumptions.

Bill Gerstenmaier, who led NASA’s human spaceflight programs from 2005 until last year, said in 2017 that at the time of the first space shuttle flight in 1981, officials calculated the probability of a loss of crew on that mission between 1-in-500 and 1-in-5,000. After grounding the loss of crew model with flight data from shuttle missions, NASA determined the first space shuttle flight actually had a 1-in-12 chance of ending with the loss of the crew.

Regardless of the fickle numbers, officials agree that a test flight of a new spacecraft is risky.

“Right now, we are trying to identify any risk that we know of that’s out there, and continue to look at risks and buy them down,” Lueders said. “But we also cant fool ourselves. Human spaceflight is really, really tough, and it’s why we continue to look for risks and do additional assessments. We never feel comfortable because that’s when you’re not searching.

“Our teams are scouring and thinking of every single risk that’s out there, and we’ve worked our butt off to buy down the ones we know of,” she said. “And we’ll continue to look and continue to buy them down until we bring them (Hurley and Behnken) home.”

In their final pre-launch press conference Friday, the Dragon astronauts said they were comfortable with the risk.

“We’ve had the luxury over the last five-plus years to be deeply embedded and understanding the trades that were made,” said Behnken, the Demo-2 mission’s joint operations commander. “There are often cases where a hardware change can be implemented, or there can be an operational change that reduces that risk, or manages it in some way.

“I think we’re really comfortable with it, and we think that those trades have been made appropriately,” he said. “As far as insight goes, we’ve had probably more than any crew has (had) in recent history.”

In addition to the tests of the Crew Dragon spacecraft itself, SpaceX has launched 84 Falcon 9 rocket missions since the first version of the launcher debuted June 4, 2010. Eighty-three of the flights successfully reached orbit.

A Falcon 9 rocket exploded during the final minutes before a ground test-firing at Cape Canaveral in September 2016. SpaceX said that failure was caused when a helium pressurant tank suddenly ruptured on the Falcon 9’s second stage.

After introducing design fixes, SpaceX has logged 59 straight successful launches using Falcon 9 and Falcon Heavy rockets.

“It wasn’t a long history (on the Falcon 9) when we started this program, but it has panned out to have quite a number of flights under its belt, and its evolution has become more and more safe as it’s been operated,” Behnken said. “Thats something that we really do appreciate. It’s remarkable to see all the other missions that have contributed to the human spaceflight program by being, in some sense, a test mission for us before we have a chance to fly on the Falcon 9.”

Email the author.

Follow Stephen Clark on Twitter: @StephenClark1.

Let’s block ads! (Why?)



Source link

Continue Reading

Science

Three powers are now capable of launching astronauts into space: Russia, China and Elon Musk – Haaretz

Published

on


It was from launchpad 39A at the Kennedy Space Center, in Florida, that Neil Armstrong, Edwin “Buzz” Aldrin and Michael Collins lifted off for the moon in 1969. It was from there, too, that the disastrous missions of the space shuttles Challenger in 1986 and Columbia in 2003 took off. But today, nine years after the last mission of the Atlantis space shuttle, only weeds emerge from the scorched asphalt. For nearly a decade, the United States has been left without a human launch system. When it has wanted to send its astronauts to the International Space Station, it has been compelled to buy places on Russia’s Soyuz spacecraft, which were launched from Kazakhstan.

In the meantime, at NASA, they were left wondering what to do with a rusting launch facility. Then, in 2014, the perfect client appeared: the eccentric billionaire engineer Elon Musk, who made his initial fortune from the sale of PayPal. The founder of the electric vehicle company Tesla and of the space exploration company SpaceX, Musk took a 20-year lease on the site. He wasn’t the only tech baron who entered a bid. When Musk’s bid was accepted, Jeff Bezos, the founder of Amazon and of the aerospace firm Blue Origin, moved quickly to lease the adjacent complex, No. 36, from which the probes were launched to Mars and Venus in the 1960s and 1970s.

Last Saturday, the fire was again ignited at launchpad 39A. NASA astronauts Bob Behnken and Doug Hurley blasted off for the ISS in a Dragon capsule. “Launch America” was the name NASA’s PR folks gave the widely covered event. The United States, it was said, had resumed launching astronauts from American soil. In fact, only the soil was U.S. property. The spacecraft, the launcher, the launch devices, even the spacesuits – all are the private property of SpaceX. The appearance of the NASA logo, which was displayed proudly on the spacecraft, was purchased. By the same token, it could have been the Coca-Cola logo that appeared there. Thus, as of the moment when these lines are being written, only three powers in the world have the capacity to launch astronauts into space: Russia, China and Elon Musk.

To understand how this situation came about, we need to go back to 2010. As the end of the space shuttle program approached, the Obama administration decided to shift to outsourcing. Instead of investing government resources in transporting cargo and people into orbit around Earth, NASA would focus on deep space ventures, such as preparation for a manned flight to Mars. As part of the plan, it was decided that NASA would develop the heavy-lift SLS (space launch system) rocket and the Orion spacecraft that would launch on it. At the same time, the federal government would encourage private investors to develop launch systems for near space – moon tourism, for example – and would underwrite trips for its NASA astronauts to the International Space Station.

The new space revolution is deceptive. To an observer on the side it looks as though commercial firms are competing with NASA. Actually, NASA is both the principal investor in the companies and their biggest client. The space agency has funneled more than $8 billion to Boeing and to SpaceX over the past decade, most of it earmarked for the development and production of launchers and spacecraft. The rest of the funds are intended to purchase 12 flights to the International Space Station for NASA – six in Musk’s Dragon and six in Boeing’s Starliner, which is also due for a debut manned launch as early as next year.

NASA is proud of the program: It has led to the development of two independent systems for sending humans into space at half of what that would cost the government. After all, the businesspeople also chipped in with a few dollars. But in the meantime, a few things happened – and a few things didn’t happen. The inauguration of NASA’s SLS has been repeatedly postponed, and the agency’s Orion spacecraft has also not yet lifted off. And China landed rovers on the moon.

A SpaceX Falcon 9 rocket and Crew Dragon spacecraft lifts off to the International Space Station from NASA's Kennedy Space Center in Cape Canaveral, Florida, May 30, 2020.

A SpaceX Falcon 9 rocket and Crew Dragon spacecraft lifts off to the International Space Station from NASA’s Kennedy Space Center in Cape Canaveral, Florida, May 30, 2020. Credit: JOE SKIPPER/ Reuters

Launch leader

During the past few years, Beijing has been investing vast sums in an effort to attain American capabilities. Already now it is leading in launches: Last year, of 102 devices launched into space, 34 were Chinese and only 27 were American in origin. This year, China is planning to launch no fewer than 48 satellites, shuttles and other mechanisms, and to leave the West in the stardust. China is eyeing the moon, and there’s concern in the United States that a taikonaut – as the Chinese call their astronauts – will plant the red flag on Earth’s satellite 50 years after the Americans left it – an image that will symbolize a new world order.

Which is why President Donald Trump signed an executive order in his first year in office instructing NASA to land an American on the moon by 2024. Mars was again shunted aside. In March, NASA announced that three companies, including those of Musk and Bezos, would compete for the privilege of bringing America back to the moon. The competitors received development grants totaling $1 billion; early next year we will learn who won the hefty contract. As for NASA’s SLS and Orion projects, they have been put on ice indefinitely. The United States will bel returning to the moon in a private spacecraft.

Actually, the heavy-launch vehicle that sent Armstrong and Aldrin to the moon was built by Boeing, and the capsule in which they landed was a product of the Grumman Corporation. But the U.S. government had purchased those fantastic machines from the manufacturer, the way one buys a car. In contrast, the spacecraft of Musk and Bezos will operate like leased cars. The United States will invest in their development, but in the end they will remain in the garages of Musk and Bezos. At the conclusion of NASA’s contract, the most expensive space assets in the world, which can do what rockets and launchers that were developed by a superpower like the Soviet Union are unable to do, will be in the private and exclusive hands of two super-tycoons.

We got a glimpse into the future of privatized space in 2018, when Musk launched his red Tesla Roadster car into space in a Falcon Heavy launcher test flight. It was a brilliant marketing gimmick: The electric sports car entered into solar orbit while its sound system played David Bowie’s “Starman” in a loop. According to Musk, he wanted to inspire people; according to others, he wanted to boost the value of Tesla shares. Be that as it may, in the coming decade Musk will be capable of sending his car to the moon, to Mars and in fact to every corner of the solar system.

In the meantime, Musk did not hesitate to transport Behnken and Hurley to last weekend’s launch in a Tesla Model X: Millions watched as the NASA astronauts got into that shiny new, Musk-produced car. When the Apollo 8 crew orbited the moon and recited verses from the Book of Genesis, American atheists sued the administration on the grounds that public funds must not be used for religious propaganda. But an advertisement for a car? In Donald Trump’s USA, not a single eyebrow was raised.

SpaceX CEO Elon Musk celebrates after the launch of a SpaceX Falcon 9 rocket spacecraft, May 30, 2020.

SpaceX CEO Elon Musk celebrates after the launch of a SpaceX Falcon 9 rocket spacecraft, May 30, 2020.Credit: STEVE NESIUS/Reuters

This is just one example of the United States’ growing dependence on the good will of businesspeople. Musk is dreaming of settling a million people on Mars. He has declared that he doesn’t want to be one of the first pioneers to land on the red planet, only to retire there, but who knows what will happen at the moment of truth? Perhaps after his space taxi successfully delivers NASA astronauts to the moon, he will change his mind and decide to launch himself in the inaugural mission to Mars.

That will be his prerogative. Musk is committed to getting NASA astronauts to the moon. He is not committed to getting NASA to Mars as well, even though the same spacecraft, with government financing, is serving both destinations. If Musk or Bezos wish to upstage NASA, they may find themselves competing with the agency. Toward the end of the decade, we might be seeing a completely new type of space race: the United States, China and two tycoons. Who will win?

And, in fact, who is who? Columbus sailed to America (as it turned out) under the Spanish flag. Armstrong flew to the moon under the Stars and Stripes. If the first flags to be planted in the soil of Mars are those of Tesla or Amazon, will it mean that “the Americans” got there first?

From the public-opinion perspective, the boisterous competition between Musk and Bezos is no less interesting than the contest between the world’s great powers. Will the landing by one corporation constitute a business and personal victory over the other corporation, or will it be a national triumph reflecting the economic and technological might of their country of origin? And what if Chinese taikonauts in a government-sponsored spacecraft land after them? Will China then be the victor in the international arena?

Reasons for concern

With heavy-lift space vehicles comes heavy responsibility, such as the need to prevent disruptive light pollution (caused both by reflective glare from the craft and by their passing in front of celestial objects) and reducing the man-made space debris that is accumulating in Earth’s atmosphere. In the meantime, Elon Musk is not giving the impression that he’s an especially responsible fellow. In fact, he’s now in the process of launching 13,000 Starlink satellites that will for the first time provide the planet, as well as future Mars settlers, with comprehensive internet service from space, thus doubling the number of active satellites of all companies and countries. This SpaceX project is already creating light pollution that conceals the stars from astronomers, and last year one of Musk’s satellites almost collided with a research satellite of the European Space Agency. Can we trust him to disinfect his spaceship of earthly bacteria before the Mars launch in order to prevent interplanetary biological pollution?

[embedded content]

Of course, heavy-lift launchers also accord many rights. Whoever controls the means to launch people into space decides who will fly. Until now, that decision was in American and Russian hands. For example, it was the United States that invited the late Israeli astronaut Ilan Ramon to join a space mission, within the framework of its special relationship with Israel. The United States has never invited an Iranian or a Chinese astronaut.

For his part, Bezos, whose vast fortune apparently spares him the need to be a media star like Musk, dreams of settling billions of people on space stations orbiting Earth. Whom will he invite? And who will he not invite? Corporations, like states, have enemies. The Chinese retail giant Alibaba is an Amazon competitor. Will Bezos agree to have Alibaba deliver packages to his colony? Or perhaps Musk will invite Alibaba founder Jack Ma to be the first tourist to do a Venus flyover, simply to rile Bezos, his space nemesis?

One thing is certain: There’s money to be made in space. Lots of money. NASA’s current administrator, James Bridenstine, estimates that the space economy is already generating revenues of $383 billion a year. If space were a country, its GNP would be higher than Israel’s. But with all due respect to satellites, the true potential of space lies in tourism and in mining minerals from asteroids or the moon. Those markets were off-limits all these years because of the staggering initial capital investment needed to reach them. Now, with the aid of government subsidies, businesspeople have developed the infrastructure to expand into both near and deep space. And to judge by the way they conduct business on Earth, they will go about it mercilessly.

In 2018, Amazon earned $11 billion and didn’t pay even one dollar in income tax. About 10 percent of the warehouse staff employed in the U.S. by Bezos – the world’s richest man – need government assistance to buy food, a higher percentage even than the hamburger flippers in McDonald’s. Some of them have to urinate into plastic bottles, for fear of the consequences if they waste time on toilet breaks. This rapaciousness is unlikely to stop in the far reaches of the universe. And it’s Bezos who is selling Amazon shares for billions every year just to enter the game. Musk has also gotten down to serious work and has already established himself as a global monopoly in the realm of commercial space launches, garnering 65 percent of all international contracts. In the first quarter of 2020, even before the successful flight of Dragon, he launched more kilograms into space than China, Russia and Europe combined.

There is no doubt that the engineers of SpaceX and Blue Origin have astonishing technological achievements to their credit. And there is also no doubt that we all want to see a Mars landing in our time. But we have to remember that we are in the meantime privatizing humanity’s interstellar future and placing it in the hands of people who can barely be restrained on Earth.

Let’s block ads! (Why?)



Source link

Continue Reading

Science

The cleanest pocket of air on Earth? It's in the Southern Ocean, between Tasmania and Antarctica – TheChronicleHerald.ca

Published

on



The cleanest air on Earth lies in a pocket of sky between Tasmania and Antarctica, scientists say.


A team of researchers at Colorado State University conducted a bioaerosol study of the Southern Ocean from Tasmania to Antarctica — the first of its kind — and drew air samples at the marine boundary level, where the atmosphere meets the ocean surface.

“We were able to use the bacteria in the air over the Southern Ocean (SO) as a diagnostic tool to infer key properties of the lower atmosphere,” microbian ecologist Thomas Hill, from Colorado State University, told

Science Alert.


Via modelling and analysis, the team noted that the samples were free of aerosol particles — a sure indicator of human activity, like fossil fuel burning, agriculture and fertilizer production — blown in from other parts of the world. The samples were also split into latitudinal zones, so that the team could observe how the air changed as they moved further south.

Via wind patterns, airborne microorganisms can travel vast distances. However, the bacterial make-up of the samples suggested that the closer they were taken to Antarctica, the cleaner they became. This suggests that aerosols from distant land masses and human activities are not travelling south into Antarctic air.


Instead, the samples appear to be composed of microorganisms from the ocean and little else.


“It suggests that the SO (Southern Ocean) is one of very few places on Earth that has been minimally affected by anthropogenic activities,” Hill said.

The results counter similar studies that were carried out in oceans in the subtropics and the Northern Hemisphere, which concluded that most microbes came from upwind continents.

Copyright Postmedia Network Inc., 2020

Let’s block ads! (Why?)



Source link

Continue Reading

Science

B.C.'s "living dinosaurs" threatened by ocean warming and acidification – Straight.com

Published

on


The world’s warming oceans and the ongoing acidification of seawater are having a serious effect on B.C.’s rare glass sponges and their associated reefs, according to a study conducted by UBC researchers.

The sponge reefs—constructed by living glass sponges growing on the skeletons of previous generations—can grow to the height of a six-storey building and were thought to have become extinct worldwide about 40 million years ago, until the discovery of  massive reefs 200 metres deep in Hecate Strait in northern B.C. in 1987 (although they had been observed as unexplained “mounds” on the floors of Queen Charlotte Sound and Hecate Strait during sonar surveys a few years previous).

At the time, the reefs were described by astonished scientists as “living dinosaurs”. German paleontologist Manfred Krautter was quoted as saying their discovery in B.C. waters “electrified” him and was “like discovering a herd of dinosaurs on land”, and the prehistoric constructs are often referred to as “Jurassic Park submerged”.

Subsequent dives by scientists in submersibles determined that they were up to 6,000 years old and covered a surface area of up to 700 square kilometres. It is theorized that the sponges, which are living marine animals, started building reefs there after B.C.’s most recent glaciation period scraped the ocean bottom clean more than 9,000 years ago.

Since the first discoveries, another 19 glass-sponge reefs have been found in the Strait of Georgia, part of what is often called the Salish Sea. An American geologist found other, specialized, reefs off the coast of Washington state in 2007.

The sponges use dissolved silica—glass, essentially—to build skeletons constructed of needlelike so-called spicules. Although glass sponges are common around the world, only in very rare cases do they form reefs, building new structures on top of the skeletons of dead sponges. The relatively accessible reefs found in Howe Sound are unique in the world for their shallow depth of less than 40 metres.

The UBC paper—published on May 18 in Scientific Reports, an open-access, peer-reviewed journal—detailed the results of an experiment initiated by Angela Stevenson, a postdoctoral fellow at UBC’s zoology department who is the study’s lead researcher. Stevenson was aided by scientists from Fisheries and Oceans Canada’s Pacific Biological Station in Nanaimo, Vancouver’s Ocean Wise Research Institute, and UBC’s department of botany.

Stevenson brought some examples of Aphrocallistes vastus—called the cloud sponge and one of three species of reef-building glass sponges found in B.C. waters—from Howe Sound to a UBC lab. Water temperature and acidity were then manipulated for a four-month study, resulting in the first successful long-term lab experiment involving living glass sponges.

““Their sheer size and tremendous filtration capacity put them at the heart of a lush and productive underwater system, so we wanted to examine how climate change might impact their survival,” Stevenson said in a June 1 UBC news release.

The researchers were monitoring the sponges’ durability, pumping ability, and skeletal strength. The results showed that the sponges experienced up to a 25 percent loss in tissue and a 50-percent reduction in pumpong capacity. Their bodies also became more elastic and lost about half their strength.

“Most worryingly, pumping began to slow within two weeks of exposure to elevated temperatures,” Stevenson noted.

Glass-sponge reefs are home to many marine creatures in B.C., including fish and giant Pacific octopuses.
Diane Reid/Ocen Wise

Glass sponges survive by pumping enormous volumes of water through their systems, filtering out the bacteria and plankton that they eat and purifying the surrounding seawater. It is estimated that the 19 reefs that are known to be in the Salish Sea can filter up to 100 billion litres of seawater every day, removing about 80 percent of the particles and microbes therein.

The Canadian Parks and Wilderness Society’s (CPAWS) B.C chapter, which advocates to protect glass-sponge reefs, says that 95 percent of seawater bacteria are filtered out by glass sponges and that a small reef of the sponges will filter and clean a volume of water every 60 seconds that would fill an Olympic-sized swimming pool.

Diver Glen Dennison above a Howe Sound glass-sponge reef.
Adam Taylor/Marine Life Sanctuaries Society

The reefs are protected by various conservation efforts in B.C’s deep northern waters and shallower Salish Sea depths, including federal marine protected areas in Hecate Strait and Queen Charlotte Sound and smaller buffer zones in Howe Sound and the Strait of Georgia. CPAWS says that research shows both measuers require expansion to fully protect the delicate structures from potential fishing and resource-exploration damage.

Borttom fishing, especially trawling, can devastate glass-sponge reefs, and suspended sediment can choke the sponges’ feeding filters and even kill them. Crab and prawn traps can damage or crush the sponge skeletons.

Jeff Marliave, an Ocean Wise senior researcher and paper coauthor, said in the release that more study is needed to understand how climate change might affect the reefs. “In Howe Sound, we want to figure out a way to track changes in sponge growth, size and area and area in the field so we can better understand potential climate implications at a larger scale. We also want to understand the microbial food webs that support sponges and how they might be influenced by climate cycles.”

Stevenson had a cautionary thought about what is required to guarantee the future safety of the reefs, whaich have been described as “international treasures”.

“When most people think about reefs, they think of tropical shallow-water reefs like the beautiful Great Barrier Reef in Australia,” Stevenson said. “But we have these incredible deep-water reefs in our own backyard in Canada. If we don’t do our best to stand up for them, it will be like discovering a herd of dinosaurs and then immediately dropping dynamite on them.”

More

Let’s block ads! (Why?)



Source link

Continue Reading

Trending