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Scientists Calculate the Risk of Someone Being Killed by Space Junk

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The chance of someone being killed by space junk falling from the sky may seem ridiculously tiny. After all, nobody has yet died from such an accident, though there have been instances of injury and damage to property. But given that we are launching an increasing number of satellites, rockets, and probes into space, do we need to start taking the risk more seriously? A new study, published in Nature Astronomy, has estimated the chance of causalities from falling rocket parts over the next ten years.

Every minute of every day, debris rains down on us from space – a hazard we are almost completely unaware of.

The microscopic particles from asteroids and comets patter down through the atmosphere to settle unnoticed on the Earth’s surface – adding up to around 40,000 tonnes of dust each year.

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While this is not a problem for us, such debris can damage to spacecraft – as was recently reported for the James Webb space telescope.

Occasionally, a larger sample arrives as a meteorite, and maybe once every 100 years or so, a body tens of metres across manages to drive through the atmosphere to excavate a crater.

And – fortunately very rarely – kilometre-sized objects can make it to the surface, causing death and destruction – as shown by the lack of dinosaurs roaming the Earth today.

These are examples of natural space debris, the uncontrolled arrival of which is unpredictable and spread more or less evenly across the globe.

The new study, however, investigated the uncontrolled arrival of artificial space debris, such as spent rocket stages, associated with rocket launches and satellites. Using mathematical modelling of the inclinations and orbits of rocket parts in space and population density below them, as well as 30 years’ worth of past satellite data, the authors estimated where rocket debris and other pieces of space junk land when they fall back to Earth.

They found that there is a small, but significant, risk of parts re-entering in the coming decade.

But this is more likely to happen over southern latitudes than northern ones. In fact, the study estimated that rocket bodies are approximately three times more likely to land at the latitudes of Jakarta in Indonesia, Dhaka in Bangladesh or Lagos in Nigeria than those of New York in the US, Beijing in China or Moscow in Russia.

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The authors also calculated a “casualty expectation” — the risk to human life — over the next decade as a result of uncontrolled rocket re-entries. Assuming that each re-entry spreads lethal debris over an area of ten square metres, they found that there is a 10 per cent chance of one or more casualties over the next decade, on average.

To date, the potential for debris from satellites and rockets to cause harm at the Earth’s surface (or in the atmosphere to air traffic) has been regarded as negligible. Most studies of such space debris have focused on the risk generated in orbit by defunct satellites which might obstruct the safe operation of functioning satellites. Unused fuel and batteries also lead to explosions in orbit which generate additional waste.

But as the number of entries into the rocket launch business increases – and moves from government to private enterprise – it is highly likely that the number of accidents, both in space and on Earth, such as that which followed the launch of the Chinese Long March 5b, will also increase. The new study warns that the 10 per cent figure is therefore a conservative estimate.

There are a range of technologies that make it entirely possible to control the re-entry of debris, but they are expensive to implement.

For example, spacecraft can be “passivated”, whereby unused energy (such as fuel or batteries) is expended rather than stored once the lifetime of the spacecraft has ended.

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The choice of orbit for a satellite can also reduce the chance of producing debris. A defunct satellite can be programmed to move into low Earth orbit, where it will burn up.

There are also attempts to launch re-usable rockets which, for example, SpaceX has demonstrated and Blue Origin is developing. These create a lot less debris, though there will be some from paint and metal shavings, as they return to Earth in a controlled way.

Many agencies do take the risks seriously. The European Space Agency is planning a mission to attempt the capture and removal of space debris with a four-armed robot. The UN, through its Office of Outer Space Affairs, issued a set of Space Debris Mitigation Guidelines in 2010, which was reinforced in 2018.

However, as the authors behind the new study point out, these are guidelines, not international law, and do not give specifics as to how mitigation activities should be implemented or controlled.

The study argues that advancing technologies and more thoughtful mission design would reduce the rate of uncontrolled re-entry of spacecraft debris, decreasing the hazard risk across the globe. It states that “uncontrolled rocket body reentries constitute a collective action problem; solutions exist, but every launching state must adopt them.” A requirement for governments to act together is not unprecedented, as shown by the agreement to ban ozone layer-destroying chlorofluorcarbon chemicals. But, rather sadly, this kind of action usually requires a major event with significant consequences for the northern hemisphere before action is taken. And changes to international protocols and conventions take time.

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In five years, it will be 70 years since the launch of the first satellite into space. It would be a fitting celebration of that event if it could be marked by a strengthened and mandatory international treaty on space debris, ratified by all UN states. Ultimately, all nations would benefit from such an agreement.


Why is Oppo making strange choices with its flagship Reno series? We discuss this on Orbital, the Gadgets 360 podcast. Orbital is available on Spotify, Gaana, JioSaavn, Google Podcasts, Apple Podcasts, Amazon Music and wherever you get your podcasts.

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Mathematical Model to Determine if Astronauts Can Safely Land on Mars Developed by Researchers

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After conducting successful Mars missions and sending rovers to explore the Red Planet, scientists are investigating the possibility of a human landing on Mars. A team of space medicine experts has proposed a mathematical model that could be used to predict if an astronaut can safely reach Mars and carry out missions after stepping on the planet’s surface. The experts tried to examine if the human body can tolerate the gravitational force of Mars without fainting or experiencing a medical emergency. They have simulated the impact of prolonged exposure to zero gravity on the cardiovascular system through the model.

According to experts at The Australian National University (ANU), the mathematical model could come in handy while determining the impact of short and long flights to Mars on the bodies of astronauts in future human missions to the Red Planet.

As Mars has weaker gravity than Earth, experts believe that continuous exposure to microgravity or near zero gravity can take a toll on the bodies of astronauts. According to Dr Lex van Loon, a Research Fellow from the ANU Medical School, exposure to zero gravity combined with damaging radiation from the sun poses the biggest risk to space travellers on the journey to Mars.

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“We know it takes about six to seven months to travel to Mars and this could cause the structure of your blood vessels or the strength of your heart to change due to the weightlessness experienced as a result of zero gravity space travel,” explained Dr van Loon. He is also the lead author of the paper published in npj Microgravity

The researcher added that the mathematical model can be used to assess if people are fit to be sent to Mars. The model uses an algorithm that is based on astronaut data collected from past space missions.

Describing the effects of zero gravity on our bodies, astrophysicist and emergency medicine registrar Dr Emma Tucker said that the fluid in our body shifts to the top half due to lack of gravity in space. This, according to her, prompts the body to think that there is too much fluid in the system. “As a result, you start going to the toilet a lot, you start getting rid of extra fluid, you don’t feel thirsty and you don’t drink as much, which means you become dehydrated in space,” Tucker added.

Hence, the new model can help determine if astronauts can safely reach the Red Planet and perform the duties they are sent for.


Do the Galaxy Z Fold 4 and Z Flip 4 offer enough over last year’s models? We discuss this on Orbital, the Gadgets 360 podcast. Orbital is available on Spotify, Gaana, JioSaavn, Google Podcasts, Apple Podcasts, Amazon Music and wherever you get your podcasts.

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New Phase of Matter Created in Quantum Computer, Could Act as Long-Term Quantum Information Storage

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Beaming a laser pulse sequence based on Fibonacci numbers at atoms inside a quantum computer, physicists have created a previosuly undetected phase of matter. What is fascinating about the phase is that it behaves as if it has two dimensions of time despite having a singular flow of time. The researchers used 10 atomic ions of an element called ytterbium, which are individually held and controlled by electric fields produced by an ion trap. These ions can be manipulated (or measured) using laser pulses. The scientists believe that this would help them in storing information in a more error-free manner. This is likely to pave way for the development of quantum computers that can hold information for a long time without distortion or loss of data.

The physicists behind the discovery did not aim their study at creating a phase with theoretical extra time. Instead, they were interested in making a new phase of matter besides the existing ones like liquid, solid, and gas.

The team set out to build a new phase in the quantum computer called the H1 quantum processor. It consists of 10 ytterbium ions that are precisely controlled by lasers inside a vacuum chamber. In the study, the team explored a special set of phases called topological phases. While moving from one phase to another, the breaking of the physical symmetries appears as the key hallmark. Even creating a new topological phase inside a quantum computer relies on symmetry breaking. However, in the new phase matter, the symmetry was observed to be breaking across time rather than space.

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In conducting the experiment, researchers used the Fibonacci sequence in which the next number in the sequence is created by adding the previous two. The Fibonacci pulsing created a time symmetry that was ordered without ever repeating just like a quasicrystal in space.

“The system essentially gets a bonus symmetry from a nonexistent extra time dimension,” said researchers from the Center for Computational Quantum Physics at the Flatiron Institute in New York. The observations have been described in a paper published in Nature.

The team has observed that the new quasiperiodic Fibonacci pulse resulted in a topographic phase that prevented data loss from the system for the entire 5.5 seconds. This meant that they had drummed up a phase that was immune to decoherence for much longer.


Do the Galaxy Z Fold 4 and Z Flip 4 offer enough over last year’s models? We discuss this on Orbital, the Gadgets 360 podcast. Orbital is available on Spotify, Gaana, JioSaavn, Google Podcasts, Apple Podcasts, Amazon Music and wherever you get your podcasts.

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NTPC Lowers Carbon Footprint; Plans Projects to Light Up 2 Lakh Households, Reduce CO2 Emissions

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NTPC Limited, India’s largest integrated energy company achieved 69454 MW of group installed and commercial capacity with the commissioning of 56 MW Kawas Solar PV Project at NTPC Kawas, Gujarat on Monday. The Ministry of Power in a statement said that NTPC is steadily lowering its carbon footprint by reducing greenhouse gas emissions through the installation of renewable energy projects in its existing stations as well as putting up green field RE projects.

The company has planned 262 MW floating solar on over 1300 acres of its reservoir area by installing over 9,50,000 PV modules at its various stations out of which 242 MW has been commissioned.

“This includes the country’s largest floating solar of 100 MW at Ramagundam in Telangana, 92 MW at Kayamkulam in Kerala, and 25 MW each at Simhadri, Andhra Pradesh, and Kawas in Gujarat,” the Ministry of Power said.

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The ministry further said that these projects would light more than 2,00,000 households and would be instrumental in reducing over half a million tonnes of CO2 emissions on an annual basis. Besides these, the projects would entail a saving of 5 trillion litres of water per annum, sufficient to meet the yearly water requirements of 15,000 households.

NTPC has become the world’s first energy major to declare its Energy Compact goals. Recently it has collaborated with NITI Aayog to achieve ‘net zero’ targets. The NTPC Group plans to achieve 60 GW of renewable energy by 2032.

Presently, NTPC has 2.3 GW of commissioned renewable capacity with 3.9 GW under implementation and execution. NTPC also has 4.9 GW of renewable energy capacity under tendering process which will further bolster the green energy portfolio of India’s largest power producer.


Do the Galaxy Z Fold 4 and Z Flip 4 offer enough over last year’s models? We discuss this on Orbital, the Gadgets 360 podcast. Orbital is available on Spotify, Gaana, JioSaavn, Google Podcasts, Apple Podcasts, Amazon Music and wherever you get your podcasts.

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