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davieG

Technology, Science and the Environment.

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I've heard of Rolls-Royce and Boeing's plans for a nuclear rocket engine. They must have money. But these companies can hardly be called space companies.
A good solution would be to combine a good team with a large company. But there can be unpredictable consequences for startups and small companies that need investment. On the other hand, limited means can lead to the invention of a method to make a launch vehicle (engine, space tug, etc.) at a minimal cost.

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23 hours ago, leicsmac said:

I think the way companies like SpaceX have changed the industry in a pretty short space of time has been fairly revolutionary tbh. The problem is that money talks, and the reason they've been able to do that is because Musk was able to use a big chunk of his PayPal wedge to get them started up properly.

 

That is a problem for most of the British companies, sadly - Reaction Engines, for instance, is doing some fantastic stuff with rocket tech but because cash is thin they're doing it really, really slowly.

What do you think of this company https://www.skyrora.com/?
Some of their statements seem to me to be quite ambitious. Although, if you want to send something into space, you probably have to be ambitious.
The company has already built and tested several rockets, a space tug, Ecosene fuel, and more.
The first launch of their Skyrora XL rocket is scheduled for 2023. Not long to wait. Hopefully nothing gets delayed as it often does.

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On 26/02/2021 at 05:52, leicsmac said:

https://www.bbc.com/news/technology-56168844

 

A sobering look at how short-term self-interest can be so damaging.

Hmm. With such news, orbital security cameras seem like a great idea. Why isn't it actually tracked? Humans can track the whale population from a satellite, but they cannot track deforestation. Something is wrong here.

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https://www.bbc.co.uk/news/science-environment-56274183

 

I'd far sooner be perched atop of a Falcon that this thing which has always reminded me of something out of a 1930s Buck Rodgers/Flash Gordon film or the Eagle comic. Early days still, but I can't comprehend the wisdom of something so tall attempting a lunar touchdown. Even in 0.17g, and taking into account the low centre of gravity of the LEM, there was concern about it landing at an oblique angle with one pad in a crater - or worse still toppling over altogether. 

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3 hours ago, Line-X said:

https://www.bbc.co.uk/news/science-environment-56274183

 

I'd far sooner be perched atop of a Falcon that this thing which has always reminded me of something out of a 1930s Buck Rodgers/Flash Gordon film or the Eagle comic. Early days still, but I can't comprehend the wisdom of something so tall attempting a lunar touchdown. Even in 0.17g, and taking into account the low centre of gravity of the LEM, there was concern about it landing at an oblique angle with one pad in a crater - or worse still toppling over altogether. 

You'd think that better mapping to find flatter sites would mean that designs like this would be easier to land as opposed to the days of Apollo.

 

But yes, I'm curious as to why a shorter or stouter design wasn't used when such things are often so critical for that landing.

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Tomorrow will be when a 1/4-mile wide lump of rock will pass close by Earth, travelling at 19 miles per second. Apophis has a 324-day solar orbit, which takes it from beyond Earth's orbit and in as far as Venus's orbit. In 8 years time, it will be much closer to us and could knock out geosychronous satellites. It's possible that this asteroid could eventually hit Earth as a result of tiny perturbations in its orbit. If it were to do so, it would be like every single one of the 15,000 nuclear weapons across the globe being detonated simultaneously.

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58 minutes ago, String fellow said:

Tomorrow will be when a 1/4-mile wide lump of rock will pass close by Earth, travelling at 19 miles per second. Apophis has a 324-day solar orbit, which takes it from beyond Earth's orbit and in as far as Venus's orbit. In 8 years time, it will be much closer to us and could knock out geosychronous satellites. It's possible that this asteroid could eventually hit Earth as a result of tiny perturbations in its orbit. If it were to do so, it would be like every single one of the 15,000 nuclear weapons across the globe being detonated simultaneously.

"Close" here is a relative term. The asteroid will remain a healthy 0.11 astronomical units (the average distance between the Earth and the sun, or about 93 million miles or 150 million km). That's nearly 44 times the distance between Earth and the moon. However, as this says, in 2029 it will come within 19,800 miles from the earth - but scientists cannot completely eliminate the albeit negligible chance that it could collide with the planet in 2068. 

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1 hour ago, String fellow said:

Tomorrow will be when a 1/4-mile wide lump of rock will pass close by Earth, travelling at 19 miles per second. Apophis has a 324-day solar orbit, which takes it from beyond Earth's orbit and in as far as Venus's orbit. In 8 years time, it will be much closer to us and could knock out geosychronous satellites. It's possible that this asteroid could eventually hit Earth as a result of tiny perturbations in its orbit. If it were to do so, it would be like every single one of the 15,000 nuclear weapons across the globe being detonated simultaneously.

 

9 minutes ago, Line-X said:

"Close" here is a relative term. The asteroid will remain a healthy 0.11 astronomical units (the average distance between the Earth and the sun, or about 93 million miles or 150 million km). That's nearly 44 times the distance between Earth and the moon. However, as this says, in 2029 it will come within 19,800 miles from the earth - but scientists cannot completely eliminate the albeit negligible chance that it could collide with the planet in 2068. 

 

WTF? :o Why am I only hearing about this now?

 

I'd made plans...

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2 hours ago, Line-X said:

"Close" here is a relative term. The asteroid will remain a healthy 0.11 astronomical units (the average distance between the Earth and the sun, or about 93 million miles or 150 million km). That's nearly 44 times the distance between Earth and the moon. However, as this says, in 2029 it will come within 19,800 miles from the earth - but scientists cannot completely eliminate the albeit negligible chance that it could collide with the planet in 2068. 

And it's thanks to the wonders of modern tech that we know it's out there at all - and be able to do something about it if it was on a more direct path.

 

Asteroid mitigation is a (darkly) fascinating area of study.

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7 hours ago, leicsmac said:

And it's thanks to the wonders of modern tech that we know it's out there at all - and be able to do something about it if it was on a more direct path.

 

Asteroid mitigation is a (darkly) fascinating area of study.

The Arecibo collapse has left us more vulnerable though. 

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The orbit of Apophis will change over time as a result of a collision with another object in space (which is unlikely), through the gravitational effect of other asteroids, or through the Yarkovsky effect. This is caused by radiation from the sun heating only one side of it. Asteroids which are prograde (solar orbit and axial rotation in the same direction) will speed up due this effect over time, increasing their solar orbits. Retrograde asteroids (solar orbit and axial rotation in opposite directions) will slow down over time, reducing their solar orbits. Apophis is prograde, as are all the planets except Venus and Uranus.  

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My son ordered an item from Amazon at 10:30 this morning, it has just arrived! :o

I bet this is replicated many times a day, all over the country.

I remember not that long ago it seems, when deliveries were usually 7 to 14 days!

I know Amazon are aiming for carbon neutral but crickey, the current effect on the environment must be colossal with all these vehicles whizzing around.

 

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On 05/03/2021 at 18:39, Free Falling Foxes said:

My son ordered an item from Amazon at 10:30 this morning, it has just arrived! :o

I bet this is replicated many times a day, all over the country.

I remember not that long ago it seems, when deliveries were usually 7 to 14 days!

I know Amazon are aiming for carbon neutral but crickey, the current effect on the environment must be colossal with all these vehicles whizzing around.

 

How would he have purchased it if not from Amazon? I'm guessing getting in a car and driving to a shop assuming there's a shop within driving distance.  If so is there that much difference as the Amazon delivery could have included others in the neighbourhood. I guess I'm saying the equation is not that simple.

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https://www.bbc.co.uk/news/science-environment-56404803

 

Plastic bags recycled into fabric to fight pollution
By Helen Briggs
BBC environment correspondent

Published17 hours ago

Scientists have made fabrics from polythene in a move they say could reduce plastic pollution and make the fashion industry more sustainable.

Polythene is a ubiquitous plastic, found in everything from plastic bags to food packaging.

The new textiles have potential uses in sports wear, and even high-end fashion, according to US researchers.

The plastic "cloth" is more environmentally-friendly than natural fibres, and can be recycled, they say.

Dr Svetlana Boriskina, from the department of engineering at the Massachusetts Institute of Technology (MIT) in Cambridge, US, said plastic bags that nobody wants can be turned into high-performance fabrics with a low environmental footprint.


"There's no reason why the simple plastic bag cannot be made into fibre and used as a high-end garment," she told BBC News.

"You can go literally from trash to a high-performance garment that provides comfort and can be recycled multiple times back into a new garment."


The fabric is made from fibres of polythene woven on industrial looms into textiles that are designed to be comfortable to wear.

Crucially, the fibres are designed to allow water to escape, rather than repelling water like conventional polythene.

The researchers say the fabric is less damaging to the environment than the likes of wool, cotton, linen, silk, nylon and polyester, and can be washed in cold water, further reducing the environmental footprint.

The plastic can be dyed in different colours before being woven into fabric. Because it is made up of only one type of plastic - polythene - it can be recycled into new garments time and time again.

The fabric has potential for use in sportswear, such as trainers, vests and leggings, they say.

In the long-term, it could also have applications as a high-performance space suit, engineered to be protect against cosmic radiation.


Commenting on the study, published in Nature Sustainability, Dr Mark Sumner of the University of Leeds said it remained to be seen if such a fabric might catch on.

He said the typical mechanical properties of polythene - such as strength and melting temperature - tend to limit its use in textiles, as does its very low moisture absorption.

"The fundamental challenge I see with this development, as we have seen with many other 'new fibre' developments, is how well the fibre aligns with comfort, feel and drape requirements of the consumer," he said.

"If the fabric feels waxy, or stiff and lacks comfort then consumers won't buy the product, and therefore, the fibre has limited use for clothing."

The fashion industry is one of the most polluting industries in the world. Textile manufacturing consumes huge amounts of water and generates millions of tonnes of waste, as well as 5-10% of global greenhouse gas emissions annually.

Washing and drying clothes often consumes even more energy and water than the production phase.

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8 hours ago, davieG said:

How would he have purchased it if not from Amazon? I'm guessing getting in a car and driving to a shop assuming there's a shop within driving distance.  If so is there that much difference as the Amazon delivery could have included others in the neighbourhood. I guess I'm saying the equation is not that simple.

I think you would acknowledge as well as I do that more and more goods are being shipped locally, nationally and globally and thus can only have a detrimental effect on the environment.

As regards jumping in a car: well people are still doing that, if the traffic on the roads this 'lockdown' is anything to go by and the full car park at our local Tesco and so on.

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3 minutes ago, Free Falling Foxes said:

I think you would acknowledge as well as I do that more and more goods are being shipped locally, nationally and globally and thus can only have a detrimental effect on the environment.

As regards jumping in a car: well people are still doing that, if the traffic on the roads this 'lockdown' is anything to go by and the full car park at our local Tesco and so on.

Of course and I'm one of them being in lockdown/housebound for over a year but I do it in the knowledge that I'm off the road. So I was just pointing out that it's not a simple equation for example when I have my food shopping delivered, for which I'm most grateful that's two journeys saved and delivered by someone who is also supplying someone else nearby as I can see that when I book my delivery.

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28 minutes ago, davieG said:

Of course and I'm one of them being in lockdown/housebound for over a year but I do it in the knowledge that I'm off the road. So I was just pointing out that it's not a simple equation for example when I have my food shopping delivered, for which I'm most grateful that's two journeys saved and delivered by someone who is also supplying someone else nearby as I can see that when I book my delivery.

If there is an overall net reduction in car travel/use due directly, even indirectly, because of home delivery then great, However I strongly suspect that isn't the case. Hence my original point about the effect on the environment.

 

To me, it would seem ordering whatever from where ever and having it delivered in hours or even a few days in the case of overseas, is unsustainable in an environmental view.

 

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