ISS: Home, Space Home.
On the ground, the International Space Station would be an odd looking building -- but space is an odd place to live!
Homes on Earth provide shelter from the wind and rain. But a home in Earth orbit must shield its occupants from the solar wind, and it must withstand a steady rain of dust-sized meteoroids, many moving faster than a speeding bullet!
A terrestrial house has insulation to keep the air inside cool or warm, but a space home must be tightly sealed just to keep the air inside.
The structure of earthbound buildings must support a constant gravitational pull of 1-g. In contrast, an orbiting structure's design should make sense in microgravity, and at the same time be able to withstand the tremendous 3-g acceleration of a rocket blasting into space.
For these and other reasons, building a structure for living in space poses a different set of design challenges than building homes on the ground.
The first thing an architect would notice about building in space is the pull of gravity -- or rather the lack thereof! A freely-falling space home in Earth orbit can take a wider variety of basic shapes than homes on the planet below.
"It's in free fall, so there's no need to say 'this is up' and 'this is down' from the standpoint of the station's architecture and structural integrity," said Kornel Nagy, structural and mechanical systems manager for the International Space Station (ISS) at NASA's Johnson Space Center.
For example, science fiction writers often imagine that a space station would be wheel shaped. As seen in the Stanley Kubrick / Arthur C. Clarke science fiction classic 2001: A Space Odyssey , these ring-shaped outposts would slowly rotate to create a centrifugal pull that acted as a false gravity. Other visionaries, such as NASA's own Wernher von Braun, also saw a spinning wheel as the most likely space station design.
So why does the ISS look more like an Erector Set than a big hamster wheel?
"Even though (the wheel design is) an elegant concept," says Nagy, "you have to think in terms of the current launch vehicles that we have and how you get all the pieces on board and assembled into a unified body."
"So the option that was looked at is to take the pressurized compartments up in segments that are as big as you can lift in a particular launch vehicle," he continued. "In our case, it's the Shuttle payload bay."
Building a home for living in space requires a little more than plywood and two-by-fours. Titanium, Kevlar, and high-grade steel are common materials in the ISS. Engineers had to use these materials to make the structure lightweight yet strong and puncture-resistant.
Because each of the aluminum-can shaped components of the Station has to be lifted into orbit, minimizing weight is crucial. Lightweight aluminum, rather than steel, comprises most of the outer shell for the modules.
This shell must also provide protection from impacts by tiny meteoroids and man-made debris. Because the ISS zips through space at about 27,000 km/h, even dust-sized grains present a considerable danger. Man-made debris, a drifting legacy of past space exploration, poses an even greater threat.
To ensure the safety of the crew, the Space Station wears a "bullet-proof vest." Layers of Kevlar, ceramic fabrics, and other advanced materials form a blanket up to 10 cm thick around each module's aluminum shell. (Kevlar is the material used in the bullet-proof vests used by police officers.)
"This protective shielding was tested by shooting at it with high-velocity guns to verify that it is indeed a good protection material," Nagy said.
Layers of Kevlar and other impact-resistant materials reduce the chance that small debris could penetrate the modules' walls and endanger the crew.
Designers had to leave a few holes in this armor so the crew could occasionally enjoy the spectacular view.
A typical window for a house on Earth has 2 panes of glass, each about 1/16 inch thick. In contrast, the ISS windows each have 4 panes of glass ranging from 1/2 to 1-1/4 inches thick. An exterior aluminum shutter provides extra protection when the windows are not in use.
The glass in these windows is subject to strict quality control, because even minute flaws would increase the chance that a micro-meteoroid could cause a fracture.
In orbit, a major force is the pressure of the air inside the ISS, which presses on each square inch of the modules' interior with almost 15 pounds of force. (Homes on Earth also have this internal pressure, but the external pressure of the atmosphere balances it out.)
But even before reaching orbit these modules must also hold up to the massive stresses of launch.
"The structure has to withstand the loading it will see while being transported to orbit, which is a pretty intense environment," Nagy said.
As the Shuttle climbs toward the edge of space, every piece of the ISS module inside will "weigh" three times normal. The structure of the modules must handle both this loading along the long axis during launch and the internal air pressure while in orbit.
Once the Shuttle has carried a module into orbit, the task remains to securely attach it to the rest of the Station.
The US-designed Common Berthing Mechanism (or CBM) links together the modules. To ensure a good seal, the CBM has an automatic latching mechanism that pulls the two modules together and tightens 16 connecting bolts with a force of 19,000 pounds each! This huge force is needed to counteract the tendency of the internal air pressure to push the modules apart and to ensure a good air-tight seal.
"A lot of development work, a lot of testing, and a lot of certification went into the CBM to be able to achieve that reliable seal," Nagy said. "So far it's worked well."
This is the first in a series of articles about the construction of the ISS. Future installments will examine the plumbing, heating/cooling, and ergonomics of the Station.
Plumbing the Space Station.Nothing goes to waste on the International Space Station where nearly everything is recycled. What makes this ecologist's dream world work? Some of the fanciest plumbing in the solar system! April 3, 2001 -- Here on Earth, household plumbing is something most of us take for granted. Turn the faucet and water comes rushing out. Flush the toilet and water disappears. What could be more routine? But have you ever stopped to wonder about plumbing ... in space? For example, which way does water flow in a weightless environment? Can toilets flush in free-fall? And if something springs a leak in Earth-orbit, which plumber would you call? There are plenty of choices, but they're all at least 235 miles (378 km) away racing by at 17,000 mph (7.5 km/s). Designers of the International Space Station (ISS) had to contend with all these questions and many more as they laid out a complex network of tubes, pipes and ducts between the Station's outer skin and its inner walls. Like veins and arteries in the human body, the Station's plumbing circulates vital liquids and gases that keep the crew and the ISS itself in good health. Most of the time the ISS -- and its plumbing -- operates as a "ship in a bottle," cut off from the outside world. Between Shuttle visits, the Station runs on a fixed amount of air and water. Efficient, leak-free recycling of everything that flows through the pipes is essential. "This is kind of an ecologist's dream house," said Dave Williams, system manager for Environmental Control and Life Support Systems (ECLSS) at Johnson Space Center in Houston, Texas. "If you built a house this way you would be reclaiming as much water as possible." For example, while a house on Earth can simply drain its wastewater to lines leading to a municipal treatment plant, the ISS must carry its own miniature water treatment plant onboard. This equipment must achieve a higher level of cleanliness than its earthly counterparts for several reasons. Unlike most municipal systems, the ISS system recycles the urine of both the crew and the laboratory animals and returns it to the drinking water supply -- and the health of the crew is of particular concern in space. Like plumbers, there are few doctors nearby! Microbes are a danger even to the Station itself, as exemplified by the problems on Mir with fungal growth. Keeping microbe levels in the water supply to an absolute minimum is an important part of ensuring the longevity of the Station. Operating "in a bottle" also complicates the plumbing of the Station because the crew can't simply open a window to get some fresh air. Tubes carry pressurized oxygen and nitrogen from the Shuttle to storage tanks on the ISS. Ducts move cabin air from all parts of the Station to the carbon dioxide scrubbers and back, ensuring that the dangerous gas doesn't build up in any forgotten corner. To be certain cabin air is safe, a mass spectrometer routinely analyzes the gas content of the air. Another network of tubes draws air samples from many different spots around the Station and feeds this air to the spectrometer, which looks at levels of oxygen, carbon dioxide, and other gases. "So if we know, for instance, there's some crew activity in a particular location that day, we can tell the computer to sample more frequently there," Williams said. The oxygen tanks -- in addition to providing a backup supply of oxygen to replenish cabin air -- attach to yet another set of tubes that supply low-pressure oxygen to the modules. Receptacles in the modules allow the crew to tap into these lines with their emergency breathing apparatuses, extending the 15-minute supply built into the breathing apparatuses so that the crew can take their time handling the emergency. And this collective network of tubing and hardware, which is far more elaborate than that of the typical house, must be compact, lightweight, corrosion-resistant, leak-resistant, microbe-resistant, and highly dependable. To meet this tall order, the pipes of the Space Station are variously made from titanium, stainless steel, or Teflon wrapped in metal mesh. In comparison, household plumbing is typically made of inexpensive PVC and copper. Along with the unique demands of a "ship in a bottle," the plumbing on the ISS must operate without the assistance of gravity. When building a house on Earth, it's enough to just lay the pipe and then let gravity or the pressure of the city water supply create the flow. In the mutual free fall of Earth orbit, liquids and gases would stagnate on their own. "You have to look at the lack of gravity carefully," Williams said. "Because normally fluids would just sit there, unless you had the head pressure to force them. In a house, you can count on gravity when you flush a toilet to take that water and put it out in the sewer." To keep the fluids flowing, the ISS plumbing system includes dozens of pumps and fans that create the pressure needed to coax the liquids and gases into moving. The mutual free fall environment also places special demands on the design of bathroom and faucet fixtures. Mass-produced fixtures like those found in a typical home won't work on the ISS. "For water faucets, it's a lot different," Williams said. "For getting a drink, we usually keep the drink in a sealed container -- it kind of reminds me of a kid's juice bag or something. You hook the bag up to the dispenser and you select how much you want and hit the button. It dispenses that fixed amount of water and then it will stop. You can't just turn on the faucet and let it go." The lavatory on the ISS looks markedly different than a bathroom here on the ground. A conventional toilet would not function at all without gravity. The ISS uses specialized equipment to meet these bodily needs. "We have to have active components to help remove the feces and urine away from the astronaut," Williams said. The two machines that separately handle these two body functions both use air flow created by suction to facilitate waste removal. With a little practice, no doubt, it seems just like home. And that's the goal of the most far-out plumbing in the solar system -- to work so well that the crew takes it for granted. After all, building a new home in space is a full time job and nobody up there wants to waste time calling the plumber. This is the third in a five-part series of articles about the construction of the ISS. The first examined the Station's architecture and structural design; the second described the Station's unique thermal control systems. Future installments will explore the power and ergonomics of the Station."Power to the ISS!"What's the most important resource on the International Space Station? Electrical power! Electrical power is arguably the most critical resource for the International Space Station (ISS). The very air in the ISS is created by splitting water molecules using electricity. Meanwhile, spare oxygen is stored in electrically pressurized tanks. Electric power wins the "most important" debate in a heartbeat. Electricity keeps the ISS and its crew alive: It powers the air and water systems, keeps the lights on, pumps liquids for recycling, warms meals, runs computers. It even lets crewmembers talk to school children by Ham radio! Indeed, electricity does it all for humanity's home in space. Supplying reliable electricity to a home gliding 350 km above our planet is no small challenge. After all, it's not as though the crew can drop a power cord down and plug it in to the city grid! And transporting fuel up from the surface would be far too expensive because of the high cost of launching rockets. In Earth orbit, the most practical source of power for the ISS is sunlight. Fortunately, solar power is plentiful. The Sun radiates 4 x 10 23 kilowatts (kW), which is a 4 followed by 23 zeros! If we could collect it all, the Sun's power output would be enough to supply the demands of 31,000 billion planet Earths, all consuming energy at 1999 levels . In fact, our planet intercepts only about a billionth of the Sun's total output, but even such a small fraction represents a large dose of power. "If we turned all the water in Lake Erie into fuel oil and burned it all in a single second, we'd produce about the same amount of energy as we get from the sunlight that strikes Earth in one day," explains Sheila Bailey, a research physicist at NASA's Glenn Research Center (GRC) in Cleveland, Ohio. The trick, of course, is to convert the Sun's copious power into a useful form. While some people (among them Wernher von Braun ) have suggested that "solar collectors" could use the heat of concentrated sunlight to produce steam to turn turbines -- much as electricity is produced here on Earth -- photovoltaic cells remain the most practical way to extract power from sunlight in space. The Glenn Research Center developed the highly-refined photovoltaic (PV) technology that is being used on the ISS. These cells are mounted on eight large, wing-like structures called solar arrays, each measuring 34 m long and 11 m wide (112 ft. x 39 ft.). The arrays together contain a total of 262,400 solar cells and cover an area of about 2,500 m 2 (27,000 sq. ft.) -- more than half the area of an American football field! A computer-controlled gimbal rotates to keep the arrays tilted toward the Sun. But the Sun is not always "up," because the ISS spends almost half its time in the shadow of Earth! The spacecraft is in eclipse for up to 36 minutes of each 92-minute circuit around our planet. During the shadow phase the space station relies on banks of nickel-hydrogen rechargeable batteries to provide a continuous power source. Those batteries consist of thirty-eight cells connected in series and packaged together in an enclosure that monitors temperature and pressure. The unit is designed to allow simple removal and replacement. The batteries, which are recharged during the sunlit phase of each orbit, are expected to last more than 5 years based on extensive testing at GRC, according to David McKissock, a power management systems analyst at Glenn. Switching back and forth between solar-generated power and stored battery power was a challenge for designers of the station's power system. The entire electrical power supply has to be switched smoothly twice each orbit, distributing reliable glitch-free current flow to all outlets and devices. "The result of this carefully managed process is 110 kW of power available for all uses," McKissock says. "After life support, battery charging, and other power management uses [take their share], 46 kW of continuous electric power are left over for research work and science experiments. That's enough to run a small village of 50 to 55 houses." ISS power is a bit different from the electricity delivered to homes on Earth, though. Rather than the familiar alternating current (AC) that courses through city power grids, the ISS runs on direct current (DC) power. Electrical devices built for the ISS are designed to use the station's 120-volt DC power, but devices from Earth such as portable CD players or electric razors must be adapted to this unusual power system. There's more to power management, however, than simply choosing between AC or DC. Two important side effects of power generation in space must be dealt with before the ISS can be a safe, working system. For one, storing electricity in batteries and managing its distribution builds up excess heat that can damage equipment. Such heat must be eliminated, so the ISS power system uses liquid ammonia radiators to dissipate the heat away from the spacecraft. The exterior radiator panels are shaded from sunlight and aligned toward the cold void of deep space. The astronaut working on the heat dissipating system must beware the possible dangers associated with producing large amounts of electricity in the plasma environment of low-Earth orbit. A second side effect could be dangerous for the astronauts themselves if not properly managed. The station's solar arrays carry a strong electric field. At the same time, the ISS is zipping through the low-density plasma that permeates low-Earth orbit (LEO). A plasma is a gas filled with charged particles that respond to electric fields -- like the ones around the solar arrays. As a result, the hull of the ISS becomes highly charged. Space-walking astronauts could suffer shocks if they touch the metal hull of the station without taking proper precautions. To counter these problems, GRC developed devices such as "plasma contactors," which neutralize the plasma charge on the ISS hull, and "circuit isolation devices," or CIDs, which enable a spacewalking crewmember to remove power from selected circuits so that the ISS power system umbilical cables can be safely attached. Without CIDs, large portions of the Station would have to be powered down during some spacewalks. Thanks to technological innovations such as these, the lights are always shining brightly -- and safely -- on the International Space Station. And NASA engineers can confidently declare, "Power to the ISS!"Staying Cool on the ISSIn a strange new world where hot air doesn't rise and heat doesn't conduct, the International Space Station's thermal control systems maintain a delicate balance between the deep-freeze of space and the Sun's blazing heat. The universe is a place of wide extremes: light, dark... wet, dry... air, vacuum... hungry, fed. Human life tends to flourish in the balance. We feel most comfortable in places that are not too hot or too cold, not too light or too dark -- in other words, places that are "just right." Most of our planet fits that description. As long as you stay away from the South Pole and don't fall into a volcano, Earth is a pretty comfortable world. But now that humans are venturing into space -- not as visitors, but as homesteaders -- finding the right balance is more of a challenge. Consider, for example, the International Space Station (ISS). Without thermal controls, the temperature of the orbiting Space Station's Sun-facing side would soar to 250 degrees F (121 C), while thermometers on the dark side would plunge to minus 250 degrees F (-157 C). There might be a comfortable spot somewhere in the middle of the Station, but searching for it wouldn't be much fun! Fortunately for the crew and all the Station's hardware, the ISS is designed and built with thermal balance in mind -- and it is equipped with a thermal control system that keeps the astronauts in their orbiting home cool and comfortable. The first design consideration for thermal control is insulation -- to keep heat in for warmth and to keep it out for cooling. Here on Earth, environmental heat is transferred in the air primarily by conduction (collisions between individual air molecules) and convection (the circulation or bulk motion of air). "This is why you can insulate your house basically using the air trapped inside your insulation," said Andrew Hong, an engineer and thermal control specialist at NASA's Johnson Space Center. "Air is a poor conductor of heat, and the fibers of home insulation that hold the air still minimize convection." "In space there is no air for conduction or convection," he added. Space is a radiation-dominated environment. Objects heat up by absorbing sunlight and they cool off by emitting infrared energy, a form of radiation which is invisible to the human eye. As a result, insulation for the International Space Station doesn't look like the fluffy mat of pink fibers you often find in Earth homes. The Station's insulation is instead a highly-reflective blanket called Multi-Layer Insulation (or MLI) made of Mylar and dacron. "The Mylar is aluminized so that solar thermal radiation can't get through it," explains Hong. Here on Earth, we use blankets containing aluminized Mylar to wrap people who have been exposed to cold or trauma. Such blankets are especially popular among hunters and campers! "Layers of dacron fabric keep the Mylar sheets separated, which prevents heat from being conducted between layers," he continued. "This ensures radiation will be the most dominant heat transfer method through the blanket." Except for its windows, most of the ISS is covered with the radiation-stopping MLI. "Windows are a tremendous heat leak," said Hong, "but astronauts need them for ergonomics and also for their research. It's something we have to design around." MLI insulation does a double-duty job: keeping solar radiation out, and keeping the bitter cold of space from penetrating the Station's metal skin. It does its work so well that the ISS presents another thermal challenge for engineers -- dealing with internal temperatures that are always on the rise inside this super-insulated orbiting laboratory fully stocked with many kinds of heat-producing instruments. Right : MLI thermal blankets are just one of the many space-age materials that protect the ISS from the harsh elements of space. Imagine that "your house was really, really well insulated and you closed it up and shut off the air-conditioning," said Gene Ungar, a thermal fluid analysis specialist at NASA's Johnson Space Center. "Almost every watt of power that came through the electric wires would end up as heat." This is just what happens on the Space Station. Energy from the solar arrays flows into the ISS to run avionics, electronics ... all of the Station's many systems. They all produce heat, and something has to be done to get rid of the excess. The basic answer is to install heat exchangers. Designers created the Active Thermal Control System, or ATCS for short, to take the heat out of the spacecraft. Waste heat is removed in two ways, through cold plates and heat exchangers, both of which are cooled by a circulating water loop. Air and water heat exchangers cool and dehumidify the spacecraft's internal atmosphere. High heat generators are attached to custom-built cold plates. Cold water -- circulated by a 17,000-rpm impeller the size of a quarter -- courses through these heat-exchanging devices to cool the equipment. "The excess heat is removed by this very efficient liquid heat-exchange system," said Ungar. "Then we send the energy to radiators to reject that heat into space." But water circulated in pipes outside the space station would quickly freeze. To make this fluid-based system work, waste heat is exchanged a second time to another loop containing ammonia in place of water. Ammonia freezes at -107 degrees F (-77 C) at standard atmospheric pressure. The heated ammonia circulates through huge radiators located on the exterior of the Space Station, releasing the heat as infrared radiation and cooling as it flows. The Station's outstretched radiators are made of honeycomb aluminum panels. There are 14 panels, each measuring 6 by 10 feet (1.8 by 3 meters), for a total of 1680 square feet (156 square meters) of ammonia-tubing-filled heat exchange area. Compare that majestic radiator with the 3-square-foot grid of coils found in typical home air conditioners and you can begin to appreciate the scope and challenge of doing "routine" things in space. Finally, thermal control engineers must address air flow within the Space Station. The movement of air is a major factor in achieving the balance between hot and cold. The ATCS works in tandem with the Environmental Control and Life Support System (ECLSS) that controls air quality and flow in the ISS. In orbital free-fall conditions -- equivalent to zero-G -- hot and cold air don't rise and fall as they do on Earth. Proper air circulation helps prevent unwanted cold spots that could produce condensation, electrical shocks, serious corrosion and even biological problems such as microbial growth. Corrosive fungi were a nagging problem on Russia's Mir space station, and ISS mission planners want to avoid a repeat infestation. It is indeed a strange new world on the ISS. Hot air that doesn't rise ... heat that doesn't conduct ... radiators too cold for liquid water ... it's enough to give a thermal engineer gray hairs! But thanks to the Station's efficient integrated thermal control systems, the crew needn't worry -- staying cool on the ISS is no problem! Editor's note : One reader asks, "If the temperature of the shadowed side of the Space Station can plunge to -250 F and if the freezing point of ammonia is only -107 F, why doesn't the ammonia in the station's radiators freeze?" The reason is that the heat-bearing ammonia can't lose heat fast enough to reach its freezing point before the liquid circulates back inside the warmer confines of the Space Station. If (as a thought experiment) we turned off the pumps and oriented the Station so that the radiator was in the shadow of, say, a solar panel, the ammonia would likely freeze after some period of time.Crew Sets Up Space Station Commode.posted: 07:45 am ET 14 September 2000 CAPE CANAVERAL, Fla. Good news for future International Space Station crews: The on-board toilet will be up and operating this week after its first official "wetting" in orbit. Working in the stations new living quarters, shuttle Atlantis astronauts started setting up the camper-like commode Thursday as they continued outfitting the outpost for its first full-time crew. astronauts started setting up the camper-like commode Thursday as they continued outfitting the outpost for its first full-time crew. STS-106 astronauts and cosmonauts float inside the International Space Station. Like plumbers on Earth, the astronauts began to mount the toilet in a cramped orbital privy, install a waste-treatment container and hook up hoses between commode components. They even will be making time for some extra bathroom duty: filling the toilet with fresh water an installation step that was going to be put off until the stations first resident crew arrives in early November. "We call it wetting," said Kirk Shireman, a senior station program manager with NASA. "And I'm sure it will make life much better for the first crew." Especially when one considers that the so-called Expedition One crew will be making a two-day trip up to the station in a Russian spacecraft not equipped with a bathroom.How the commode keeps you down.Now the station toilet will be ready to go when the first crew is ready to go. And heres how it will work: Located inside a small water closet, the commode is similar to a space shuttle toilet, which has dual thigh bars and foot restraints to keep people from floating off its seat. In order to operate in zero gravity, the commode uses suctioned air to pull waste into a treatment canister below it. "Its much like you would find on a camper or out on a boat," said U.S. astronaut William Shepherd, commander of the Expedition One crew. "This one is a little bit different though, because its got airflow and that keeps all the waste going in the right direction." Into the waste container, that is. Shaped like small drums, the waste containers eventually fill up, so theyll be replaced with empty canisters every three to four weeks. Used canisters will be stored on Russian Progress supply ships, which double as trash trucks that burn up during suicide dives into the atmosphere. Armed with a video camera, Atlantis pilot Scott Altman took time early Thursday to give viewers a televised peak inside the stations privy, which looks something like an airline lavatory. The washroom is equipped "with all the facilities -- everything that you need including a mirror on the wall for doing that morning shave and getting ready to go, brushing your teeth and washing your hair," Altman said.Moments alone."Theres a privacy door on the bathroom, obviously, to make sure that everybody can have their moments alone." The orbital plumbing chores kicked off as the Atlantis crew cruised toward the midway point of a 12-day shuttle flight. The only hitch so far: one of three batteries the astronauts installed in the stations new living quarters is acting erratically, but project managers say there will be plenty of electrical power to support the first resident crew. During their latest 16-hour shift, the shuttle crew continued unloading some 6,000 pounds (2,700 kilograms) of supplies and equipment from a Progress cargo carrier and a shipping container in Atlantis cargo bay. Meanwhile, two Russian spacesuits that will be used by spacewalking station construction workers were unpacked and stowed within the outpost. And the astronauts fired shuttle thrusters in a successful bid to boost the stations altitude by 3 miles (4.8 kilometers), propelling the outpost to an orbit 236 miles (378 kilometers) above the planet. Still to come: the initial set-up of crucial station life-support systems, such as oxygen-generation machines and carbon dioxide scrubbers. A daylong effort to install an exercise treadmill also is on tap before the shuttle crew departs the station this weekend. Atlantis and its crew landed at Kennedy Space Center at 3:40 a.m. Eastern Daylight Time (07:40 GMT) September 20. Previous chapter:Next chapter0: Odd, but interesting: 1: 10 Confounding Cosmic Questions 2: Top 10 Cool Moon Facts. 3: Top 10 Star Mysteries 4: Top 10 strangest things in space. 5: The Wildest Weather in the Galaxy 6: Space Station Assembly. 7: ISS: Home, Space Home. 8: Impressive New Tricks of Light, All Within the Laws of Physics 9: Earth-Moon size and distance 10: Dictionary Results for magnetism : 11: Exploring Mars: Basic Mars Facts:- 12: THE MOON 13: What's New on the Moon? 14: Precession: 15: Sedna: A Clue to Nibiru Part 1:Part 2:Part 3: |
(Wednesday, 22 April, 2026.)
