11 CUTTING EDGE MATERIALS SET TO SHAPE THE FUTURE

Building Blocks of Innovation: 11 Cutting Edge Materials Set to Shape the Future
By SA Rogers, Web Urbanist, 18 April 2018.

Architecture has looked much the same since early humans first began constructing their own shelter, but that could change soon with the introduction of new materials and technologies producing almost alien-like forms. Woven carbon fiber, ultra-strong but amazingly thin concrete, transparent wood and 3D-printed sandstone are among the innovations that could break free of the traditional constraints and result in a new era of lightweight, durable, versatile forms in all sorts of organic and mathematical shapes.

1, 2 & 3. Super Wood, Nano Wood and Transparent Wood

Wood is an ancient material, and it isn’t going anywhere. Not only is wood construction enjoying a renaissance of sorts, with super-tall wood structures planned around the world, it’s seeing fascinating modifications that make it stronger and more versatile than ever. Researchers at the University of Maryland have created a ‘super wood’ that’s stronger than steel but six times lighter. First, they boil the wood in a mixture of sodium sulfite and sodium hydroxide to partially remove the lignin fiber and hemicellulose, and then hot-press it to crush the cell walls, creating durable nano fibers. This process could be carried out on wood species that are traditionally too soft for many applications, potentially shifting the entire logging industry.

The same research team also transformed wood into an insulating material that’s stronger and more environmentally friendly than styrofoam using a similar process. This ‘nano wood’ is created by removing the lignin (which gives woods its color and rigidity) as well as some of the short fibers “that make up the scaffolding-like base structure of the wood,” they explain. “The aligned cellulose fibers then bond with each other and results in a high mechanical strength.” When pressed in a certain direction it’s 30 times stronger than typical thermal insulation materials and a lot more insulating (blocking at least 10 degrees more heat than the record-setting best simulator, silica aerogel.)

Oh yeah, and then there’s transparent wood. When the lignin is leached out using that same chemical bath that’s used to make ‘super wood,’ and then the wood is soaked in epoxy, it turns the wood clear. The result looks like plastic, is stronger than glass, won’t shatter on impact and actually biodegrades. While not fully transparent, it’s able to transmit up to 90 percent of light.

4. Fungus-Based Self-Healing Concrete

Concrete may rarely need maintenance in the future thanks to a special species of fungi known as Trichoderma reesei, which acts as a sealing agent when added to the mix. Taking inspiration from living creatures’ ability to regenerate tissue, researchers at Binghamton University determined that the fungus lies dormant until a new crack appears, at which point its spores germinate, expand and produce calcium carbonate to fill the crack in response to oxygen and water. Considering how much infrastructure in the United States is currently crumbling, it could make a huge difference in the durability of what we build in the future.

“Without proper treatment, cracks tend to progress further and eventually require costly repair,” they explain. “If micro-cracks expand and reach the steel reinforcement, not only the concrete will be attacked, but also the reinforcement will be corroded, as it is exposed to water, oxygen, possibly CO2 and chlorides, leading to structural failure.”

The way the fungi works, “When the cracks are completely filled and ultimately no more water or oxygen can enter inside, the fungi will again form spores. As the environmental conditions become favorable in later stages, the spores could be awakened again.”

5. Thin-Film Photovoltaics Embedded in Concrete

Not only are we likely to see a lot more sculptural structures made of incredibly thin layers of concrete thanks to digital design and fabrication techniques, but they could be pre-embedded with thin film solar cells. This prototype was created by researchers at the Swiss Federal Institute of Technology Zurich with a surface thickness of around two inches and edges just an inch thick.

Mixed within the concrete are heating and cooling coils and insulation, and the formwork is made of a polymer textile stretched across cable netting.

6. Carbon Fiber: This Century’s Steel?

At the Autodesk BUILD (Building, Innovation, Learning and Design) Space in Boston, researchers are experimenting with all kinds of potential future building materials, and carbon fiber is among the most promising. Inspired by the way spiders and silkworms weave, this ultra-strong material is lighter than steel, twice as stiff and five times stronger, and the way the hair-thin threads are woven produces freeform, organic-looking architecture. Carbon fiber is already used to make all kinds of things, from fishing poles to the masts of sailboats, but robotic building techniques are bringing it to a whole new level. The University of Stuttgart and its graduates are among the innovators in this area, producing amazing woven pavilions each year to show off possibilities.

What’s more is the fact that woven carbon fiber structures could easily be added to existing architecture made of more conventional materials in order to strengthen, update or otherwise modify it, saving hundreds of years of existing construction.

7. Recycled Plastic Bricks Fabricated On-Site

We’ve literally covered our entire planet in non-biodegradable plastic trash, a monumental foible for a species that’s supposed to be so smart. What can we do with it all? One idea is gathering it up and transforming it into building blocks. Various companies and research facilities are already making it happen, like startup ByFusion in the United States, which has a patented process to compact the plastic into construction-quality bricks.

The best part is the fact that all the equipment to do so fits inside a shipping container and can be operated in all sorts of locations with no emissions. The plastic doesn’t even have to be sorted or washed first.

8. Graphene: A Wonder Material with Intriguing Potential

Graphene is a ‘wonder material’ known for its impressive strength and light weight. This semi-metal consists of a single layer of carbon atoms arranged in a hexagonal lattice, making almost all of its strength two-dimensional, so it’s been tough translating it to three-dimensional applications. But researchers at the Massachusetts Institute of Technology discovered that when the material is shaped into a sponge-like form, it resists forces 10 times greater than steel. They compressed small flakes of graphene into magenta colored polymer in a shape resembling corals and diatoms and found that its thin walls allowed it to deform incrementally, helping it withstand pressure.

The model represents new ways of thinking about graphene, which could lead to breakthroughs in the immediate future. MIT believes graphene could someday be used to build things like long-span bridges. To gain a better understanding of graphene, check out an infographic at Futurism.

9 & 10. Super-Lightweight Aerographite and Graphene Aerogel

The world’s lightest material is a porous carbon material known as aerographite, developed by scientists at Kiel University and Hamburg University of Technology. As seen in this photograph, it’s so light, it can balance on a drop of water. Created by a network of carbon tubes three-dimensional interwoven at nano level, the material is 75 times lighter than styrofoam, electrically conductive and non-transparent.

“It is able to be compressed up to 95 percent and be pulled back to its original form without any damage,” says Professor Rainer Adelung. “Up to a certain point the aerographite will become even more solid and therefore stronger than before.”

Those scientists say the aerographite material they developed is four times lighter than aerogel, but it didn’t take long before their work was eclipsed by a team from China’s Zhejiang University in the form of ‘graphene aerogel.’ Made of freeze-dried carbon and graphene oxide, it weighs a mere .16 milligrams per cubic centimeter and has a density lower than helium. They made it into a sponge-like form and balanced it on delicate objects to show just how light it really is. It’s also highly absorbent and elastic. It was deemed the world’s “least dense” material by the Guinness Book of World Records in 2016. The researchers are still determining the material’s real-world applications.

11. The Intricate Possibilities of 3D-Printed Sandstone

Ornamentation of the sort we’ve never seen in architecture could be realized with 3D printing, and liquified sandstone may be one of the materials used to create structures of H.R. Giger levels of intricacy, as demonstrated here by designers Michael Hansmeyer and Benjamin Dillenburger. Their ‘Digital Grotesque’ large-scale sculptures show off complex, interwoven and sometimes fractal details that couldn’t be achieved by hand, with the architectural scale reduced from bricks to grains of sand.

Smaller 3D-printed modules are assembled into a whole. Imagine the potential this kind of technology holds for building facades in a hypothetical future in which we’ve moved past minimalism into a new baroque era in which we don’t mind all those tiny crevices getting grimy.

Top image: Digital Grotesque II, the full-scale 3D printed grotto. Credit: Demetris Shammas via eVolo.

[Source: Web Urbanist.]

10 SURPRISING SECRETS ABOUT AIR TRAVEL

10 Surprising Secrets About Air Travel
By Kristine Alexander, Toptenz, 30 April 2018.

Flying has become an increasingly common way to travel, with more than 37 million commercial flights flown in 2017. However, even if you’re a frequent flier, there may still be some things you don’t know. Below, find 10 surprising facts about air travel that may be new to you, or at least fresher than the blankets on your next flight…

10. The tiny hole at the bottom of your window is keeping you safe

When you’re stuck in an aluminum tube for hours at a time, staring out the window at the clouds might provide a welcome diversion from the cramped seats, crappy food, and unruly fellow passengers you may encounter as part of your in-flight “experience.” And when you look out that window, you may have noticed something strange about the window itself - the pin-sized hole near the bottom. That tiny hole is called a “bleed hole” or “breather hole,” and it’s there for a reason.

As your plane makes its way up to its cruising altitude, air pressure drops. The plane’s pressurization system keeps the air pressure much higher in the plane then in the surrounding air, ensuring that oxygen levels remain high enough for the people on the plane. This pressure differential puts a lot of stress on the plane’s windows, but each window is made up of three panes of glass to keep passengers safe. The innermost layer is mainly to keep the other two safe from passengers. The middle pane is the one with the tiny hole, which ensures that the outermost pane is the one to bear the pressure (and that it is the one that would break if the pressure became too much. If anything happened to the outermost pane, the middle pane would be able to “take over” handling the pressure differential without compromising the passenger cabin. The bleed hole also serves to manage the temperature differential between the cabin and the surrounding air, keeping the windows (mostly) clear of fogging and frost.

9. Airplane bathrooms can be unlocked from the outside

Airplane lavatories have improved from their early incarnations, some of which just released waste directly into the air. Nonetheless, most people wouldn’t describe them as pleasant or seek to spend any unnecessary time in them. In recent years, aircraft bathrooms have become even more cramped, as airlines seek to maximize the number of seats they can squeeze onboard, making visiting the lavatory an even more claustrophobic experience for passengers. Those rare few who still can’t get enough of the aircraft lavatory should be aware of one fact - it is possible to unlock the lavatory door from the outside.

The mechanism for doing so varies from plane to plane. In some versions of the Airbus A380, for example, one must simply lift the “lavatory” sign and slide the knob over to unlock the door. While this might seem like a great way to prank a friend (or a helpful trick for dealing with a misbehaving child), a Virgin America flight attendant says this technique is often used in reverse, to lock the door of an empty bathroom shut during turbulence, further noting that unlocking an occupied bathroom would be done only to ensure passenger safety, in the event the occupant has been in there a long time and is unresponsive, or if the smoke alarm goes off.

8. Hot beverages are best avoided when you’re in the air

While a cup of coffee or tea may seem like the perfect way to wake up after a red-eye flight, you might be better off waiting until you’re inside the airport to enjoy a hot beverage. Not only will the diaretic effect of coffee and tea have you making extra visits to the tiny plane bathroom, the water used to make your drink may be pretty gross.

After an EPA study in 2004 showed 15% of water samples taken from more than 300 planes had coliform bacteria, new standards were introduced to ensure airlines cleaned and tested their water tanks for bacteria. However, the water systems on some planes are only cleaned and tested once a year. EPA data from 2012 shows that 12% of commercial planes still had at least one positive test for coliform bacteria. Coliform bacteria won’t make most people sick, but does show that the plane’s water systems are not the cleanest water source, and that more dangerous bacteria, such as E. coli, could potentially exist in that environment. While US carriers serve bottled water to passengers, water from the plane’s system is still used to make tea, coffee, and cocoa, and it doesn’t generally get heated to the temperatures needed to kill all bacteria. The danger is likely small, but it’s enough to keep some flight attendants from drinking coffee and tea onboard, and maybe enough that you’d rather get your caffeine fix from soda or wait till you’re in the terminal to grab a coffee or tea.

7. There’s a reason why airplane bathrooms still have ashtrays, even though smoking is banned

You may have noticed an odd feature in the airplane lavatory - an ashtray on the back of the door. Confusingly, it’s often located right under the sign that reminds you that smoking is prohibited. On most US domestic flights, smoking has been prohibited since 1990, and it’s been outlawed on flights between the US and foreign destinations since 2000. But ashtrays can still be found even on brand new planes - why?

In the US, the bathroom ashtrays are there because the FAA mandates that they be. While initially, this make seem like another nonsensical law, there’s actually a pretty obvious reason why it makes sense to keep the ashtrays: not everyone obeys the law against smoking on planes. On a flight from Portland to Sacramento, one woman, who claimed she needed to smoke to deal with “anxiety,” became so violent after a flight attendant stopped her from smoking in the bathroom that she had to be restrained by passengers and crew until the plane could make an emergency landing.

Given that there are some people who are going to try to sneak in a cigarette no matter what the law says, no matter what kind of hefty fines might be assessed, it makes sense to make sure the cigarettes can be put out safely, and not tossed in a trash bin full of flammable paper towels. The legally mandated presence of ashtrays on planes has its roots in the tragic case of Varig Flight 820 in 1973. An on-board fire, possibly started by a lit cigarette tossed in the lavatory trash bin, killed most of those aboard (via smoke inhalation) before it could make an emergency landing, prompting the FAA to ensure that all commercial aircraft were equipped with ashtrays going forward.

6. Some planes have teeny-tiny bedrooms for the crew

On long-haul flights (those over 10.5 hours), you may have noticed that the crew members serving you rotate during the course of the flight. With some flights (like those from LA to Singapore and from New Zealand to Qatar) clocking in close to 18 hours, it makes sense that more than one crew of pilots and flight attendants would be needed to staff the plane, rotating between work and rest.

But where does the crew go when they are resting? While they all have seats in the main cabin for takeoff and landing, you don’t see the crew snoozing in them during the course of the flight. That’s because planes that fly these long-haul flights are equipped with special little bedrooms for the pilots and flight attendants (usually the pilots and flight attendants sleep in different quarters because of their different schedules). These sleeping cabins are either above or below the main passenger cabin, and are accessible by little staircases or, in some cases, via an overhead storage bin. Configurations vary based on the airline/plane, but generally include single beds, an overhead light for reading, and a privacy curtain. A KLM flight attendant reports that KLM crew beds come equipped with a set of mandatory KLM PJs, so that the crew is recognizable if they are called into service during an emergency.

5. Occasionally, a plane lands with more passengers than appear on the original manifest

This one isn’t as cryptic as it sounds. Pregnant passengers are generally permitted to fly up until their 36th week of pregnancy, though some carriers will require a note from a doctor or midwife after 28 weeks. However, as many moms will attest, due dates aren’t always accurate. Some babies make their entrance earlier than expected, and occasionally, these surprise preterm births happen at 36,000 feet up.

When babies are born on international flights, determining citizenship can be quite a tricky matter. Usually, the child will be accorded the citizenship of one or both of its parents. Some countries, including the US, will also grant citizenship to a baby that is born within national airspace. Additionally, 70 countries have ratified or acceded to the UN Convention on the Reduction of Statelessness, which says that a baby born on an aircraft is entitled to citizenship in the country where the plane is registered, but only if that baby would otherwise be “stateless.” Perhaps out of gratitude for the positive news coverage they bring for air carriers, some (though not all) babies born in flight have received perks from the airline where they made their debuts - including scholarships and free flights.

4. Flight crews want to get the door closed and the plane pushed back as fast as possible, even if they know they’ll be a tarmac delay

We know that everyone wants to get the plane in the air as fast as possible (well, except for that one guy casually blocking aisle with the full-size suitcase he insists will fit in the overhead bin), but the pilots and flight attendants are motivated not just by the desire to depart and land on time (for which they may receive some bonus pay), but also by the fact that, on many airlines, the crew isn’t paid until the plane door is closed and the parking brake of the plane is disengaged. Flight crews may receive some pay for long delays at the gate, but the pay gets much better when the plane pushes back.

While some airlines only pay the flight crew for the time they are actually in the air, most pay them once they leave the gate. While most pilots and flight attendants want to avoid delays altogether, if there’s going to be a delay, they’d much rather it be on the tarmac (where they get full pay) versus at the gate (where they get minimal or no pay).

3. Pilots have secret distress signals, though sometimes they mess them up

Pilots have ways to communicate, both verbally and nonverbally, that their plane is in distress. Obviously, we don’t know all the current ways that pilots signal problems on board to outside observers, but we do know some of what has been used in the past.

In the air, depending on the nature of the emergency, pilots are trained to set their transponder code (or “squawk” in pilot lingo) to a number corresponding to their situation, in order to alert air traffic control. Squawking 7500 signals hijacking, 7600 stands for loss of communications, and 7700 is a general emergency signal. Additionally, for a hijacking, a pilot would add the word TRIP following the aircraft designator (for example, “United TRIP 319”) when communicating with air traffic controllers, as an indicator that he or she was unable to communicate freely (likely due to monitoring by the hijacker[s]). In 2011, on a flight from Chicago to Frankfurt, a United pilot spilled coffee on the communications equipment, resulting in an accidental squawk of code 7500. The plane’s crew was able to confirm with officials on the ground about the communications error, though the plane was still diverted to Canada because of the issue. Another in-air distress signal involves flying the plane repeatedly in a triangular pattern, a maneuver that indicates to radar stations that the plane is unable to establish radio contact.

In the past, the plane’s wing flaps have been used to communicate distress on the ground. If the wing flaps were lowered while the plane was still on the ground, or full flaps were left down after landing, this signaled a request for immobilization of the aircraft and armed intervention. In 1986, a pilot inadvertently triggered a response by a SWAT team by taxiing for takeoff with the aircraft’s wing flaps down.

While some of these above techniques have been rendered less necessary by the fortified cockpit doors that became standard after the 9/11 attacks, there are still situations where these, and other distress signals, can provide necessary information about the plane’s situation to allow those on the ground to formulate a proper emergency response.

2. Pilots and copilots can’t eat the same meal

“Fish or chicken?” This question may be a vestige of the past on most domestic flights, but many international carriers still offer passengers a choice of entrée for long-haul flights. For the pilot and co-pilot though, the answer is pretty much set: they’ll each eat a different entrée. The reason for this is pretty obvious: eating different meals reduces the chance that both pilots will be incapacitated by food poisoning during the course of the flight.

This rule is not law, but is a policy at many airlines. A China Eastern pilot reports that generally the pilot takes a first class meal and the co-pilot takes one from business class. Lufthansa also confirms that it has an “unwritten rule” that pilots and co-pilots should avoid eating the same thing before the flight (for the same reason). Not every airline has this rule (though pilots may still follow it out of common sense), and even when pilots avoid the same meals, it’s not foolproof. In 1982, 10 crew members (including the pilot, co-pilot, and flight engineer) became sick on a flight from Lisbon to Boston. Luckily the plane was less than an hour from its destination, and it was able to land safely. The crew had eaten different meals, but were sickened by the same dessert - tapioca pudding.

1. Your best chance for a free upgrade is to die mid-flight

There are many purported tricks for scoring a free seat in first class, but unless you are an elite frequent flier or pay for an upgrade (with money or miles), your chances of moving up from economy to first class are remote. There’s one exception - but not one many of us would be willing to pursue. If you die mid-flight, your body is likely to get a post-mortem upgrade.

Airline protocol means that, technically, very few people ever die on a flight, since death must be declared by a doctor to be officially recorded. However, when it’s clear to all onboard that a passenger has passed away, airline personnel are trained to move the body to a relatively private location. This could mean an empty row of seats, but those can be hard to come by on crowded flights. The first class cabin generally has more empty seats and offers more room to maneuver the deceased, so that’s where bodies are often moved, and usually covered by a blanket to avoid traumatizing the other passengers. Previous solutions relied on deception: one British Airways flight attendant recalls that “many years ago,” dead passengers were simply handled Weekend at Bernie’s-style–propped up with a drink, eyeshades, and a newspaper in the hopes that other travelers would assume they were just sleeping.

Singapore Airlines used to have a so-called “corpse cupboard” on A340s it used for long-haul flights, though when the planes were taken out of service, the company noted the compartments had never been called into action. There’s one place you won’t end up if you die on a plane: the bathroom. Because rigor mortis could make it hard to get the deceased out again, flight attendants are discouraged from moving dead passengers into the lavatory.

Top image credit: 733215/Pixabay.

[Source: Toptenz. Top image added.]

5 FOODS BESIDES ROMAINE THAT CAN HAVE E. COLI

5 foods besides romaine that can have E. coli
By Robin Shreeves, Mother Nature Network, 27 April 2018.

You've probably heard about the U.S. government's current warning to avoid romaine lettuce, which has been linked to a multistate E. coli outbreak. The warning applies to romaine grown in the Yuma, Arizona, growing region and covers romaine lettuce in all forms - chopped, whole heads and hearts, and salads and salad mixes containing romaine sold in grocery stores as well as restaurants. The U.S. Centers for Disease Control and Prevention (CDC) is warning people throughout the country to throw away any romaine unless they're absolutely sure it didn't come from the Yuma region, even if they've already eaten some and haven't gotten sick.

So far, 98 people in 22 different states have been infected with E. coli after eating romaine lettuce. No one has died, but more than 40 have been hospitalized and 10 have been diagnosed with hemolytic uremic syndrome, a type of kidney failure.

Raw vegetables and fruits are often a source for E. coli because the bacteria can't be fully washed off. Thoroughly cooking produce will kill the bacteria, but that's the only way to be certain contaminated fruits and vegetables are safe. Raw vegetables are not the only food that can be contaminated, though.

Here are five other foods that you'll see recalled from time to time because of E. coli, along with tips on how to safely prepare them.

1. Sprouts

Photo: Buelldm/Wikimedia Commons

Sprouts are grown in warm, humid conditions ideal for the growth of bacteria like E. coli, as well as salmonella and listeria. They're at their most dangerous when eaten raw, but cooking them can reduce risks and kill harmful bacteria. Between 1996 and 2016, there were 46 U.S. outbreaks of food-borne illness from sprouts. In 2017, the U.S. Food and Drug Administration (FDA) began taking steps to curb the high number of bacterial illnesses linked to contaminated raw sprouts.

2. Water

Photo: Hans/Pixabay

Bottled water is usually safe when it comes to bacterial contaminants, but in 2015, Niagara Brand bottled water issued a recall out of an abundance of caution because of possible E. coli contamination, even though no illnesses were reported. The danger from E. coli-infected water usually comes from sources like private wells or drinking straight from a body of water that has been contaminated. If you're getting your drinking or cooking water from a source that could possibly be contaminated, there are ultraviolet water-treatment systems that can kill the bacteria, or in a pinch, boiling the water for at least one minute will also kill contaminants.

3. Beef

Photo: Hungry Dudes/Flickr

Earlier this year, 7 tons of ground beef were recalled because of E. coli contamination. These bacteria commonly live in the digestive tracts of cows, whose meat may become infected during slaughtering and processing. Since E. coli in beef is fairly common, beef should be fully cooked before being consumed. That means a medium-rare cheeseburger, while delicious, may also be dangerous. To stay clear of E. coli poisoning from beef, burgers, steaks, roasts and other cuts of meat, they should be cooked to well-done. The U.S. Department of Agriculture recommends cooking beef to an internal temperature of 160 degrees Fahrenheit (71 Celsius).

4. Unpasteurized juice

Photo: stevepb/Pixabay

Pasteurization kills bacteria in juice (and in dairy and eggs), but fresh juice can have E. coli passed on from the fresh produce it was made from. In 2013, 13 people became ill from E. coli after drinking unpasteurized apple juice from High Hill Ranch in California. The one sure way to avoid E. coli in any juice is to make sure it's been pasteurized before drinking it.

5. Deli meats

Photo: Didriks/Flickr

Deli slicers aren't typically cleaned between each use, given the impracticality of sterilizing them after every order. But, because of this, if one package of deli meat contains E. coli, the bacteria can spread to other meats prepared on the same slicer. While the risk from deli meats isn't as high as fresh produce or raw meats, a CBS News report indicates about half of locations visited by FDA inspectors didn't clean and sanitize their meat slicers as often as the FDA recommends. When buying deli meat, you might want to inquire about how often their slicers are cleaned. And discard of any sliced deli products that have been in your refrigerator for more than a few days. The longer they sit, the more the bacteria can grow.

While people with a healthy immune system generally make a full recovery from E. coli poisoning, there are some cases - as with the recent romaine outbreak - when healthy individuals can still suffer serious health problems. Those with compromised immune systems, the elderly and infants face the highest risks from E. coli poisoning and should see a doctor immediately if symptoms occur. According to WebMD, symptoms appear two to five days after E. coli has been ingested; the most common symptoms are abdominal cramps, diarrhea, nausea and fatigue.

Top image: Romaine lettuce. Credit: US Department of Agriculture/Wikimedia Commons.

[Source: Mother Nature Network. Images added.]

10 DANGEROUS OBJECTS ORBITING THE EARTH

10 Dangerous Objects Orbiting The Earth
By Vaughn Nida, Listverse, 27 April 2018.

There are at least 500,000 objects orbiting the Earth today. Some estimates put the figure closer to 700,000. More than 21,000 are larger than 10 centimeters (4 in), and these objects pose a threat to future space travel and life on Earth. Many are fragments of artificial satellites that were destroyed when they collided with other satellites.

Today, there are over 1,700 artificial satellites in operation and an additional 2,600 that are no longer working. Most of these satellites have either completed their missions or have succumbed to malfunction. At least 30 of these inoperable objects were nuclear powered at some point. They still contain - and in some cases, leak - nuclear waste to this day.

The following list discusses 10 objects in orbit around Earth that are worrisome for different reasons.

10. Tiangong-1

Photo credit: space.com

Tiangong-1 is a prototype space station launched by the Chinese government in 2011. It originally had a two-year mission to test the effects of space travel on astronauts and the docking capabilities of other spacecraft. The mission was extended beyond its original plan before finally being abandoned because the operators of the station in China claimed that they no longer had control of it.

Although the station is still in orbit today, it is losing altitude quickly and will fall to Earth in early 2018. Tiangong-1 is large, weighing about 8,500 kilograms (19,000 lbs), and is capable of housing two astronauts at a time.

Although most of the station will incinerate in the atmosphere, the expectation is that the rocket engines are made of materials that will not burn up. These engines will come crashing to Earth at some approximated time and unknown location. They could cause enormous damage to structures, animals, human beings, and the planet itself.^[1]

9. SNAP 10-A

Photo credit: ENERGY.GOV

In 1965, the United States launched SNAP 10-A into space from Vandenberg Air Force Base. SNAP 10-A is the only nuclear fission satellite launched into space by the United States. It was designed as an experimental nuclear spacecraft capable of producing 500 watts of electrical power. Its primary purpose was to monitor how nuclear fission reactors behave in space.

Unfortunately, the nuclear reactor worked for only 43 days, and then the power supply’s voltage regulator failed. The satellite started to fall apart in the late 1970s, and approximately 50 pieces of debris have been created as a result.^[2]

During this shedding process, it was very likely that some radioactive material was released into space. The nuclear reactor currently orbits the Earth at 700 nautical miles above the surface. It will remain in orbit for the next 4,000 years unless additional shedding or a collision with another object shortens its orbital life.

8. Kosmos 1818

Photo credit: space.com

In 1987, the Soviet Union launched Kosmos 1818, which was powered by a TOPAZ 1 (or thermionic) nuclear reactor. The purpose of Kosmos 1818 was as a naval surveillance satellite, or RORSAT (Radar Ocean Reconnaissance Satellite). Unfortunately, the nuclear reactor on Kosmos 1818 operated for only five months before shutting down.

In 1978, a similar satellite reentered the atmosphere and crashed into Earth, spreading radioactive material over Canada. Kosmos 1818 was placed into high orbit to avoid a similar catastrophe. However, its high orbit also means that it has a high collision probability.

Any collision might accelerate the descent of possibly contaminated materials to Earth. Some of the objects and liquid released from the spacecraft are thought to be radioactive and are still in orbit.^[3]

7. Kosmos 1867

Photo via Wikimedia

Kosmos 1867 was launched by the Soviet Union in 1987, the same year as its twin, Kosmos 1818. It had a similar purpose to Kosmos 1818, but Kosmos 1867 operated for 11 months before shutting down.

Since it is in a high orbit like its twin, Kosmos 1867 has succumbed to the pressures of repeated solar heating. As a result, the coolant tubes aboard the satellite’s nuclear reactor have cracked and allowed the release of liquid metal into space.^[4]

6. Kosmos 1900

Photo credit: rcinet.ca

Kosmos 1900 is a US-A or Controlled Active Satellite used for RORSAT missions. Launched in 1987 by the Soviet Union, the satellite was plagued from the beginning and never quite reached the cruising orbit for which it was designed.

After several rocket boosts to try to correct its orbit, the satellite continued to lose altitude. Moreover, the nuclear reactor did not make it into its storage orbit. At some point prior to 1995, NASA determined that a cloud of liquid radioactive material had originated from the Kosmos 1900 satellite. NASA claimed that the leak was likely due to a collision with another satellite.^[5]

5. Satellite Debris

Photo credit: aerospace.org

With all the satellite collisions, there is now a large debris field orbiting Earth. This debris field is perhaps more dangerous than any single intact object because of the increased chance of potential collisions from multiple debris objects. Several large satellite collisions have already been recorded, and these events have exacerbated the space junk problem.

In 2009, the satellites Iridium 33 and Kosmos 2251 collided at a speed of 42,000 kilometers per hour (26,000 mph) while in low Earth orbit (approximately 800 kilometers (500 mi) above the planet’s surface). Both satellites were destroyed by the collision.

So, instead of having two large objects orbiting Earth, we now have approximately 1,000 objects larger than 10 centimeters (4 in) that threaten many other satellites. (There are also many smaller pieces.)^[6]

Although about half the debris from the 2009 accident has now burned up in the atmosphere, several other collisions have occurred. Scientists estimate that the Iridium-Kosmos accident, along with China’s intentional destruction of a satellite by long-range missile in 2007, has doubled the number of dangerous and potential collision objects in orbit.

4. Black Knight

Photo credit: NASA

Whether Black Knight is dangerous will depend on whom you ask. Conspiracy theorists argue that the object is a 13,000-year-old extraterrestrial satellite from the star system Epsilon Bootis that Nikola Tesla discovered in 1899. NASA claims that the object in question is nothing more than a thermal blanket that got loose during a space walk.

This object is dangerous mostly for the time that is wasted on it by conspiracy theorists. Unfortunately, more time has been wasted by conspiracy theorists and speculation about this object than all the time lost by those who died prematurely as result of falling space debris.^[7]

3. International Space Station (ISS)

The International Space Station (ISS) does not present a nuclear or likely collision threat that we know of, but it remains one of the most dangerous objects in orbit because of its size. Collisions are possible with any space object, but any such accident with the space station could create a doomsday scenario involving space debris that is proposed by the Kessler syndrome.

In simple terms, this means that an object striking the ISS might cause a cascading effect of other such accidents from all the resulting debris. At some point, there would be too much debris for us to continue with certain space activities, possibly for generations. As recently as 2017, objects have detached from the station and now have the potential to crash into the ISS.

The station is also a danger to the astronauts who work aboard it. There have been several problems with the oxygen generators, carbon dioxide removal systems, environmental controls, the central computer, electrical and power systems, torn solar panels, and ammonia leaks.^[8] If one of these problems turned into a catastrophe, the ISS could quickly become a serious danger as it fell to Earth and collided with other satellites and debris along the way.

2. Hubble Space Telescope

The Hubble Space Telescope is not as big as the ISS. But Hubble is still one of the largest objects in orbit and a danger mostly for its collision potential. If Hubble were to strike another satellite or piece of debris, the amount of additional wreckage would significantly add to the space debris problem.

Initially, Hubble was launched aboard the Discovery space shuttle in 1990 after a multiyear delay following the destruction of Challenger. Currently, Hubble is not in a controlled orbit and is descending toward Earth.

As Hubble’s materials are so strong and dense, the space telescope is not likely to burn up in the Earth’s atmosphere during descent. After entry into the atmosphere, Hubble would then fall uncontrolled to the Earth’s surface. This is likely to occur sometime between now and 2040.^[9]

1. Envisat

Photo credit: esa.int

Envisat is a large satellite launched in 2002 to monitor the Earth’s environment and geography. Although it lasted five years beyond its original plan, the European Space Agency (ESA) lost contact with it in 2012. Envisat now poses the greatest Kessler syndrome threat in Earth’s orbit.

Two objects pass close to Envisat and could cause a collision. Considering Envisat’s mass of approximately 8,200 kilograms (18,000 lb), any crash between it and other satellites or pieces of space junk would be catastrophic and create a large debris field that would be nearly impossible to clean up.

The wreckage of Envisat would be so immense that the potential chain reaction of collisions proposed by the Kessler syndrome is the real danger, and Envisat represents its greatest risk.

Currently, the satellite is expected to continue in orbit for approximately 150 years before falling to Earth, which greatly increases the probability of an accident. For this reason, special considerations have been made to create a spacecraft capable of removing Envisat from orbit.^[10]

Envisat is perhaps one of the greatest ironies of our space program: A satellite that was celebrated for helping us to understand the health of the Earth’s environment is now one of the greatest risks to its orbital field.

Top image: A computer-generated image representing space debris as could be seen from high Earth orbit. Credit: NASA/Wikimedia Commons.

[Source: Listverse. Top image added.]