How Close Are We to Nuclear Fusion Reactors?

Harnessing nuclear energy as an energy source has long been an idea surrounded in mystery and fear. Very few people actually know how nuclear power plants work, but many people know how catastrophic nuclear reactor meltdowns can be. However, the kind of nuclear energy we can currently control in nuclear power plants is only one of two kinds of nuclear energy. Current reactors rely on nuclear fission-the breaking of large atoms into smaller atoms. Nuclear fusion, combining small atoms into bigger atoms, is currently demonstrated in the core of our sun and hydrogen bombs. That raises the question: how close are we to being able to (safely) utilize nuclear fusion?

Nuclear fusion has long been seen as a better alternative to nuclear fission for 3 main reasons: the elements needed for fusion are much more common than the ones needed for fission, the by-products of fusion are much safer than fission’s by-products, and fusion could potentially lower the risk of reactor meltdowns. The biggest problem scientists currently struggle with is figuring out the “breakeven energy point” of nuclear fusion: the point where we maximize our energy output without fearing a runaway reaction resulting in a nuclear explosion. Currently there are two approaches that are making serious headway towards reaching this breakeven point. Internal Confinement uses lasers to compress a chunk of Hydrogen and force it to undergo nuclear fusion. The only problem is that those lasers currently use more energy than the nuclear fusion creates, but a recently invented laser promises to output much more energy which could trigger stronger nuclear fusion reactions. The other leading idea is Magnetic Confinement Fusion that uses magnetic fields to compress the hydrogen into nuclear fusion. Recently, a very small research team in California created a new way to increase the density, temperature, and confinement time of the hydrogen in a MCF system, which could lead to higher energy outputs. Both of these systems have seen recent breakthroughs, but they might still be quite a way away from reaching the break-even energy point. With that said, mankind is closer to safely harnessing nuclear fusion than ever before.

Image credit: Lawrence Livermore National Laboratory.
Diagram illustrating the Internal Confinement principle Source
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Voyager; Humanity’s Furthest Trace

Voyager1

The Telegraph

golden disk
NASA Archive

 

As time progresses, the sun will eventual expand, engulfing the rocky worlds of our solar system. With Earth vaporized, evidence of human life on Earth will disappear with the planet. Long after Earth’s demise the Voyager probes will continue to roam the cosmos, caring  evidence of human life, waiting to be discovered by an alien civilization.

 

While the Voyager probes were launched with the primary intent of the Voyager probes was to collect data on the giants planets of our solar system, the probes served the secondary purpose of transporting golden records into the interstellar space. After collecting data on the planners they flew by, the probes were gravitationally  slingshot out of the solar system. Voyager 1 and Voyager 2 now drift on at speeds of 17 and 14 km/s respectively into interstellar space.

 

The record the probes carry contain pictures and audio that describe human science, culture, and society.  However, a playback device is needed to display this data. For this reason, the casing of the golden record contains instructions on how to built the playback device. Given that extraterrestrial life would have no grasp on the human alphanumerical system, the instructions for how to build the device and other information about humanity is written in terms of universal constants, such as the lowest energy state of a hydrogen atom. These records may maintain humanity’s legacy beyond the destruction of Earth.

 

 

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Voyager; Humanity’s Furthest Trace

Voyager1

The Telegraph

golden disk
NASA Archive

 

As time progresses, the sun will eventual expand, engulfing the rocky worlds of our solar system. With Earth vaporized, evidence of human life on Earth will disappear with the planet. Long after Earth’s demise the Voyager probes will continue to roam the cosmos, caring  evidence of human life, waiting to be discovered by an alien civilization.

 

While the Voyager probes were launched with the primary intent of the Voyager probes was to collect data on the giants planets of our solar system, the probes served the secondary purpose of transporting golden records into the interstellar space. After collecting data on the planners they flew by, the probes were gravitationally  slingshot out of the solar system. Voyager 1 and Voyager 2 now drift on at speeds of 17 and 14 km/s respectively into interstellar space.

 

The record the probes carry contain pictures and audio that describe human science, culture, and society.  However, a playback device is needed to display this data. For this reason, the casing of the golden record contains instructions on how to built the playback device. Given that extraterrestrial life would have no grasp on the human alphanumerical system, the instructions for how to build the device and other information about humanity is written in terms of universal constants, such as the lowest energy state of a hydrogen atom. These records may maintain humanity’s legacy beyond the destruction of Earth.

 

 

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Nuclear Fusion

sun
The sun, where nuclear fusion occurs. It is the process allows the sun to keep shining

When it comes down to it, nuclear fusion is the basis for all life. Nuclear fusion is the combination of two atoms. This combination produces energy in the form of mass, and new elements with more protons than those that were used to create that element. Fusion happens on the sun due to the high temperature and pressure that allow atoms to get close enough that a strong nuclear force takes over, and the atoms combine to form a new element. Energy is released during this process because some excess mass, say electrons, are ejected, and release energy due to E = mc^2. This energy generation is also what makes it so interesting to us.

Now, we always hear about the upcoming energy crisis. Our current sources of energy, natural gas and fossil fuels, will one day inevitably run out. At some point, we need a form of energy that will never run out. Nuclear fusion could be the solution. On Earth, the easiest way for fusion to occur is with deuterium and tritium. Each is an isotope of hydrogen, with deuterium having one extra electron and tritium having two. Each is easy to access on Earth. When the atoms are combined, some mass is ejected, and energy is released.

It may seem like a simple solution, but it is actually far more complicated than I may have just revealed. Creating conditions where fusion will occur is extremely difficult. The protons in an atom must get close enough so that the strong nuclear force will overcome the repelling force of the positive charges getting near each other. The search to have a reliable source of nuclear energy is on. With many projects and multiple countries working, one would hope that soon, this solution to our energy problem will become reality.

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Nuclear Fusion

sun
The sun, where nuclear fusion occurs. It is the process allows the sun to keep shining

When it comes down to it, nuclear fusion is the basis for all life. Nuclear fusion is the combination of two atoms. This combination produces energy in the form of mass, and new elements with more protons than those that were used to create that element. Fusion happens on the sun due to the high temperature and pressure that allow atoms to get close enough that a strong nuclear force takes over, and the atoms combine to form a new element. Energy is released during this process because some excess mass, say electrons, are ejected, and release energy due to E = mc^2. This energy generation is also what makes it so interesting to us.

Now, we always hear about the upcoming energy crisis. Our current sources of energy, natural gas and fossil fuels, will one day inevitably run out. At some point, we need a form of energy that will never run out. Nuclear fusion could be the solution. On Earth, the easiest way for fusion to occur is with deuterium and tritium. Each is an isotope of hydrogen, with deuterium having one extra electron and tritium having two. Each is easy to access on Earth. When the atoms are combined, some mass is ejected, and energy is released.

It may seem like a simple solution, but it is actually far more complicated than I may have just revealed. Creating conditions where fusion will occur is extremely difficult. The protons in an atom must get close enough so that the strong nuclear force will overcome the repelling force of the positive charges getting near each other. The search to have a reliable source of nuclear energy is on. With many projects and multiple countries working, one would hope that soon, this solution to our energy problem will become reality.

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Shine on, Crazy Diamond

All the light we see and information we receive in our day to day lives is all thanks to the sun- but do we ever really stop to think what allows the sun to produce to light we so rely on?

The sun actually relies heavily on quantum physics to even exist- which sounds very impressive, but keep in mind that the sun is a normal star! This means that every star in the universe that exists on the main sequence will undergo the following processes:

When a star exists in hydrostatic equilibrium (being that the outward pressure balances the inner force of gravity) the star “lives”, persay, on the main sequence. When on the main sequence, the star consumes its elements through a process called Hydrogen burning. (keeping in mind that stars are mainly composed of Hydrogen and Helium, with heavier metal cores) This process is also known as the p-p chain reaction. In this reaction, 4 Hydrogen atoms are fused into one Helium nucleus, releasing 26.73Mv of energy in the process. Amazingly enough, this process is only 7% efficient, being that the sun could theoretically be almost ten times brighter if so much energy was not lost in the chemical reaction!

Once the process of hydrogen burning has built up enough dissipated heat energy to raise the temperature of the star, another process called the CNO cycle begins. In this process,  carbon is cyclically created and destroyed, with reaction by products of Helium, gamma rays, and neutrinos. This will cause the star to heat up even more, and eventually move off the main sequence when it expands to a red giant.

Thankfully, we don’t have to worry about that for billions of years- we can just enjoy the sunshine for now! (and be more mindful of the incredible chemical reactions that power it)

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Extreme Weather Patterns Across the Solar System

With stories about giant hurricanes devastating coastal towns and earthquakes shaking up cities on the fault lines, many people call weather on Earth extreme. When temperatures rise above 85°F or rains last for more than two days, people are quick to complain about Earth’s weather patterns. However, weather here on Earth is very mild compared to some weather patterns happening on our distant space neighbors.

Mercury is the smallest planet in the solar system and the closest to the sun. Mercury’s atmosphere barely exists; therefore, the small terrestrial planet cannot trap any heat from the Sun. Combined with the planet’s close proximity to the sun, Mercury undergoes some extreme temperature fluctuations. During the day, Mercury can reach temperatures of about 800°F. During nighttime, temperatures can drop to -290°F.

Venus, another terrestrial planet much closer in size to Earth, has a very thick atmosphere made up of mostly carbon dioxide with a tiny percentage of nitrogen. Clouds of sulfuric acid also exist on Venus, and these clouds are the reason the planet experiences one of the most extreme weather cases in the solar system. On Earth, clouds are formed from water droplets, hydrogen oxide molecules, and when these clouds condense, normal rain is the outcome. On Venus, though, since the clouds are made of carbon dioxide and sulfuric acid, when these condense, the rain is actually sulfuric acid. The planet is so hot, though, that the rain evaporates before hitting the ground.

jupiter spot
Jupiter’s Great Red Spot by NASA

Jupiter, the largest planet in the solar system, has a thick atmosphere of hydrogen and helium. This gas giant is home to huge, extreme storms such as the Great Red Spot, a hurricane-like storm that has been raging on since it was discovered over 400 years ago. Jupiter also houses over 30 jet streams, some reaching speeds up to 300 miles per hour. Recently, scientists discovered that in both Jupiter and Saturn, diamonds could be floating the hydrogen and helium fluid. At lower depths, scientists speculate that higher temperatures and immense pressure can melt the diamonds and cause liquid diamonds to rain from the sky.

Saturn, another gas giant, has an atmosphere much like Jupiter’s. Winds on this planet can reach speeds of 1100 miles per hour, and like Jupiter, scientists believe that diamonds are floating in the planet’s atmosphere and growing large enough to be considered “diamondbergs.” Nearer to the surface of Saturn, carbon is pressurized into graphite, meaning not only would travelers have to be wary of raining diamonds, but also raining pencil lead. Saturn also houses extreme storms. At the north pole of the second largest planet in the solar is a major storm system shaped like a hexagon with each side of the shape being 8,600 miles long. Another storm is over 6,400 miles across, which is the equivalent of traveling from Los Angeles, California to Beijing, China.

While Earth’s weather patterns do seem extreme at times, humans really take for granted the relatively pleasant conditions that are usually present. No one here on Earth ever has to worry about being pelted with diamond rain or being swept away by a humongous windstorm.

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Extreme Weather Patterns Across the Solar System

With stories about giant hurricanes devastating coastal towns and earthquakes shaking up cities on the fault lines, many people call weather on Earth extreme. When temperatures rise above 85°F or rains last for more than two days, people are quick to complain about Earth’s weather patterns. However, weather here on Earth is very mild compared to some weather patterns happening on our distant space neighbors.

Mercury is the smallest planet in the solar system and the closest to the sun. Mercury’s atmosphere barely exists; therefore, the small terrestrial planet cannot trap any heat from the Sun. Combined with the planet’s close proximity to the sun, Mercury undergoes some extreme temperature fluctuations. During the day, Mercury can reach temperatures of about 800°F. During nighttime, temperatures can drop to -290°F.

Venus, another terrestrial planet much closer in size to Earth, has a very thick atmosphere made up of mostly carbon dioxide with a tiny percentage of nitrogen. Clouds of sulfuric acid also exist on Venus, and these clouds are the reason the planet experiences one of the most extreme weather cases in the solar system. On Earth, clouds are formed from water droplets, hydrogen oxide molecules, and when these clouds condense, normal rain is the outcome. On Venus, though, since the clouds are made of carbon dioxide and sulfuric acid, when these condense, the rain is actually sulfuric acid. The planet is so hot, though, that the rain evaporates before hitting the ground.

jupiter spot
Jupiter’s Great Red Spot by NASA

Jupiter, the largest planet in the solar system, has a thick atmosphere of hydrogen and helium. This gas giant is home to huge, extreme storms such as the Great Red Spot, a hurricane-like storm that has been raging on since it was discovered over years ago. Jupiter also houses over 30 jet streams, some reaching speeds up to 300 miles per hour. Recently, scientists discovered that in both Jupiter and Saturn, diamonds could be floating the hydrogen and helium fluid. At lower depths, scientists speculate that higher temperatures and immense pressure can melt the diamonds and cause liquid diamonds to rain from the sky.

Saturn, another gas giant, has an atmosphere much like Jupiter’s. Winds on this planet can reach speeds of 1100 miles per hour, and like Jupiter, scientists believe that diamonds are floating in the planet’s atmosphere and growing large enough to be considered “diamondbergs.” Nearer to the surface of Saturn, carbon is pressurized into graphite, meaning not only would travelers have to be wary of raining diamonds, but also raining pencil lead. Saturn also houses extreme storms. At the north pole of the second largest planet in the solar is a major storm system shaped like a hexagon with each side of the shape being 8,600 miles long. Another storm is over 6,400 miles across, which is the equivalent of traveling from Los Angeles, California to Beijing, China.

While Earth’s weather patterns do seem extreme at times, humans really take for granted the relatively pleasant conditions that are usually present. No one here on Earth ever has to worry about being pelted with diamond rain or being swept away by a humongous windstorm.

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Volcanism on Venus

Related image

What Volcanism on Venus looks like- Image Source

Venus has hardly any wind erosion because of its slow rotation, and no water erosion because there is no liquid water on Venus. Therefore, the biggest changes in the surface of Venus are a result of volcanism. Venus has a vast array of volcanoes covering its’ surface; the largest Volcano on Venus, up to this date, is the Sapas Mons and it is 4 km tall. These volcanoes have smooth plains all around them formed by the lava. Volcanoes have formed many geological features including Canalis which are channels that are carved out by the lava. These channels are much larger than the channels seen in any other terrestrial planet. Another geologic feature that has formed are the lava flow fields which were most likely a result of extended volcaninc activity with high levels of magma spurting out of the volcanoes. Volcanism in Venus has led to many old craters being covered up with lava, and has changed the appearance of its’ surface as a result.

Information from the Smithsonian National air and space Museum

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Sky Crane wow

 

PIA14839-br2
Not your mothers’s crane

So you know how NASA thinks outside the box to solve crazy space problems? The Sky Crane on the Mars Science Laboratory probe mission was a solution to a crazy space problem that was also a feat of engineering and technology.

The problem

Landing on Mars safely. NASA wanted to deliver the Curiosity rover to the surface of Mars to investigate the Martian climate and geology. This simple concept proved more than complex very quickly. The atmosphere on Mars is only 1% the density of Earth’s, so while spacecrafts still produce heat and friction while travling through it, it is not thick enough to meaningfully slow a spacecraft. The thinner atmosphere also affects parachute deployment, as there are fewer molecules to fill the parachute. The atmosphere effectively nullifies slowing via parachutes or wind breaking. There is also no convenient way to test the opening of a parachute in a thinner atmosphere. Curiosity was also too heavy to use airbags — the heavy landing would certainly cause the airbags to fail.

Any landing also has to happen autonomously. Light takes 12.5 minutes on average to travel one way between Earth and Mars, so adjusting the landing protocols in real time is virtually impossible.

Getting close to the surface is a problem that has been solved before. However, the details of landing on Mars necessitate a new innovation.

The solution

20090428MSLEntry2
Source

Sky crane.

After the main rover module was released from the parachute as depicted in the figure above, its flight computer used altitude and velocity data to align itself with the Martian surface to enter the sky crane configuration. While levitating in the air with the help of four rocket thrusters called Mars Lander Engines, the rover was released from the holding bridle and was slowly lowered 7.6m to the surface below. Curiosity was tethered to the bridle using three nylon tethers and an electrical cable to transfer the necessary power and information between the modules. The cables unreeled, and each of the six wheels on the rover popped into place. Once on the ground and after a brief confirmation that the rover was indeed on the ground (done by testing the weight applied on the wheels), the cables were severed using small explosives. The bridle then flew away and crashed 650m away to ensure that no dust from the crash interfered with the rover’s sensors.

The sky crane had never been used before, and it had never even been tested fully because Mars was just too different than Earth to yield usable results. Here is a video of some drop testing they did

See the Sky Crane in action.

Obviously, many factors had to happen perfectly for a successful operation. Any flaw in the descent parachute or heat shield would be catastrophic. An error in any of the assembly’s sensors could have led to Curiosity hitting the ground from a fatal height. A failure in the explosives that disconnected the rover form the bridle would have led to the bridle carrying off Curiosity on its crash landing. NASA and ESA both would have suffered great losses had another Mars rover failed to deploy, so it was a great relief that everything worked as expected.

giphy
Mars

Source – Source – Source – Source

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