Planned debris recovery satellite

[Martin DowingParticipant @martindowing58466]

Debris on low orbit gradually decay due to traces of atmosphere present there. within few decades they would fall into air and burn.

Debris on geostationary orbit would not suffer this fate due to a lack of appreciable quantities of gases causing orbit decay.

If they are of small size (say 1 mm) and released in quantities of many millions, no conceivable technology exist to clear them out (or even to track them) and natural orbit decay could take many millenias.

So such debris are permanent for all practical purposes.

Martin

Edit:

I remember statements that blobs of plasma sufficient to damage satelites are formed when weight of debris is in range of 10-100mg. This would comfortably fit into tungsten ball diameter of 1-2 mm, hence edit of my initial post.

Edited By Martin Dowing on 01/12/2017 10:29:31

[Martin KyteParticipant @martinkyte99762]

Thanks Martin. "(So such debris are permanent for all practical purposes.)"

Just wanted to know what you ment by permanent.

regards Martin

[Chris TriceParticipant @christrice43267]

If anyone is interested enough to seek them out, the National Space Centre in Leicester has pieces of micrometeorite damaged spacecraft parts on display in the tower section. It's frightening how much damage a grain of sand sized particle can do at the impact velocities we're talking about.

[Geoff TheasbyParticipant @geofftheasby]

In the 1950/60s there was a suggestion to place into orbit millions of fine copper needles that would spread out and form a reflecting layer for radio signals. Good job that didn't happen. Now here we are again.

Edit. Oh, they did! Project West Ford. The needles did mostly disperse and fall back to Earth & burn up.

Geoff

Edited By Geoff Theasby on 01/12/2017 11:39:25

[Martin Botting 2Participant @martinbotting2]

Its simple…. just mention you left some redundant copper pipe and old bedstead in the front garden / somewhere near the moon and I can guarantee it will be gone before you blink, well it works here in south London!

[Alan Johnson 7Participant @alanjohnson7]

Moon Landing.

One of my Lecturers in the 70's was an Amateur Radio buff. He was very keen on sattelite dishes – cutting edge technology at the time. He said that in 1969 he had his dish aimed at the Moon, and was watching the "free to air" TV signal coming from the Moon!

Llikewise, I have a friend who is a Doctor of Geology, and therefore not a fool, who is an amateur astronomer, and his comment on the subject is that they – the amateur astronomers (in Australia), where watching the activities on the Moon. He said that " … they could see the "Moon Lander" and the astronaughts moving around on the Moon – with their telescopes"!

I know it happened!

[Andrew TinsleyParticipant @andrewtinsley63637]

Think someone is pulling your leg, no way could an amateur telescope see such fine detail!

With regard to clearing all the space junk, I reckon that it is an almost impossible task, you would need thousands of satellites that were highly agile to even make a dent in the number of objects orbiting the earth.

Andrew.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Mick Charity on 30/11/2017 21:34:16:

I'm wondering if it isn't all just nonsense, like the moon landings.

…

Despite the best efforts of an intelligent disbeliever at work to prove me wrong, I'm happy that the moon landings were genuine.

Such doubts aren't to be discounted lightly because of the number of other facts that are wrong. For instance:

• James Watt did not invent the steam engine
• George Stephenson did not invent the steam locomotive or standard gauge railways
• Alexander Graham Bell did not invent the telephone
• Samuel Morse did not invent Morse Code or the Electric Telegraph
• Marconi did not invent Radio
• Robert Watson-Watt did not invent Radar
• Frank Whittle did not invent the Jet Engine
• John Logie-Baird did not invent television
• Thomas Edison did not invent the filament light bulb
• The Wright Brothers did not invent the aeroplane
• Einstein did not invent the atom bomb

And of course many people had discovered America before Christopher Columbus. It's just that before Columbus it had always been possible to cover it up…

Dave

[Chris TriceParticipant @christrice43267]

I've said this before but just because lots of people lack the intellectual capacity to understand the science that made the Moon landings possible doesn't mean it didn't happen. I find the arrogance of those that say it must be a conspiracy simply because they personally can't get their head around it hard to deal with. It's all part of the "my ignorance is as good as your knowledge".

No it isn't.

I'm afraid Alan that you were indeed having your leg pulled if they claim to have seen the TV signals and heard the radio of the astronauts with an amateur dish. There were only seven or eight dishes in the wold considered good enough to receive and refine the signals to a sufficiently good standard and these were all around 200ft in diameter or more.

[Dod MoleParticipant @georgeclarihew]

Posted by Martin Kyte on 01/12/2017 09:07:45:

It's getting really crowded up there.

This site is quite interesting

**LINK**

The issue is to come up with a way of reducing the risk of serious damage to sattelites before the usefull orbits become untenable. Can you imagine a world without sttelite communication these days. No satnavs, much of telecomms gone, reduced weather monitoring, loss of all sattelite data gathering for earth sciences. Not to mention space telescopes.

regards Martin

Sheer bliss

[Barnaby WildeParticipant @barnabywilde70941]

Posted by Chris Trice on 01/12/2017 17:24:12:

I've said this before but just because lots of people lack the intellectual capacity to understand the science that made the Moon landings possible doesn't mean it didn't happen. I find the arrogance of those that say it must be a conspiracy simply because they personally can't get their head around it hard to deal with. It's all part of the "my ignorance is as good as your knowledge".

No it isn't.

So, all moon landing deniers are idiots then?

Can you bring yourself to believe that they lied to us, as they have with so many other things.

[Alan VosParticipant @alanvos39612]

I do recall, aged 8, being dragged out of bed early on the grounds of "this is history in the making, you will remember this" to watch the first man walk on the moon. According to a popular source that was 02:51 UTC. I think we were on double summer time, so around 5am local.

[Phil WhitleyParticipant @philwhitley94135]

"Frank Whittle did not invent the Jet Engine" Go on then, who did?

[Martin DowingParticipant @martindowing58466]

Re Moon landing deniers.

Russians were closely watching American activities and if there is some credible evidence that Moon claims were false, this would surely be flagged in communistic block but it was not. Hence it is unlikely that Americans cheated.

Some small cheat, where the Eagle could simply make an orbit or few around a Moon and come back on Earth without landing there is still technically possible, particularly in regard to first visits reported.

IMO all these landing deniers are coming from quite unconfortable situation that humans are already post peak in respect to manned space conquest, eg we are not going there anymore, not to the Moon and not anywhere else, due to lack of courage and most imprtantly lack of resources to make it happen again. Basicly reasoning is that if now, after so much progress we are not going there, then initiat claims are surely a lie. Technologically inferior society cannot achieve something what more advanced one cannot. This reasoning is false but nevertheless convincing for many.

So regardless, what the truth is, as long as the venture is not repeated again, school books (or their electronic version) 200 or 300 years from now on will treat Moon landing claims as great myth of XX century, of course provided that peoples 200 or 300 years into the future will still be able to read and write. Our education system is doing all it can to make sure that it will not be the case.

Martin

[Martin DowingParticipant @martindowing58466]

"Frank Whittle did not invent the Jet Engine" Go on then, who did?

Most likely few junior engineers working together with him.

Martin

[Phil WhitleyParticipant @philwhitley94135]

Posted by Ady1 on 01/12/2017 00:39:08:

might be easier to use magnets to reroute junk into a different trajectory away from earth

Even non ferrous metals can be induced to change direction via lenz law stuff, they do it in recycling works

My thoughts exactly!, but then they gave the job to scientists instead of engineers!

[Andrew TinsleyParticipant @andrewtinsley63637]

I was under the impression that the first jet engine to be developed and flown was in Germany and predated Whittle by 2 or 3 years.

But I suppose this doesn't go down too well with the "We won the war brigade".

Andrew.

[Geoff TheasbyParticipant @geofftheasby]

Frank Whittle's design dates from 1928, but didn't fly until 1940. Von Ohain's design came later, but flew in 1936.

Geoff

[Dave HalfordParticipant @davehalford22513]

We wont go back to the moon until there either a money reason or national pride makes someone find the money.

[SillyOldDufferModerator @sillyoldduffer]

First Jet Engine. A little blurred depending on what you define as a 'Jet Engine' but quite a few people involved, including:

• Hero 150BC
• Leonardo da Vinci's Smoke Jack, about 1500, very commonly used to drive roasting spits when cooking was done over an open fire
• Stoltz 1872. Modern form, engine not built until 1900, not successful in an aircraft due to inefficiencies and poor materials.
• Armengaud & Lemale built a 25HP unit around 1901, followed by a 400HP design with a Rateau compressor built by Swiss Brown Bovari. Worked inefficiently due to poor compressor performance and low-quality blades
• Holzwarth in 1905 plus Karavodine and Lorin in 1908 started to develop designs resulting in a 350kW engine in 1923 for the Prussian State Railways and a 5000HP unit for a German Steelworks.
• Coanda 1910. Discovered the 'Coanda Effect' which is the tendency of a fluid flow to stick to a surface. It set fire to his aircraft!
• Small turbine driven superchargers were developed in the 1920s and 1930s by several workers notably Buchi and Moss. Turbo-superchargers increase the power of a piston engine by about 50% and allow the engine to work at high altitude. The work is most significant because it led to the development of heat-resistant steels suitable for turbine blades.
• A large Process Gas Turbine was developed by Brown Bovari in 1936 for use in petroleum cracking. It's success led Brown Bovari to later develop the first gas turbine powered generator and the first locomotive powered only by a gas turbine.

Whittle was inspired work by started by Lorin. He deserves full credit for his 1930 patent describing a turbo-jet intended for use in an aircraft. The patent was a considerable advance on earlier work and it was fairly obvious that Whittle's ideas were practical. The patent appears to have kick-started military funded projects in at least Germany (von Ohain) and Italy. In Germany the Heinkel Hirth HeS3 flew in August 1939. The flight was not a success and development of the engine was transferred to BMW and Junkers. In Italy the Caproni-Campini CC2 with a Lorin based engine flew for about 10 minutes in August 1940, again not very successfully. (A year later the aircraft had a top-speed of less than 200mph).

Whittle's first engine ran in 1937 and had compressor, turbine and combustion chamber issues. Whittle designed the compressor and turbine and the combustion chamber was designed by Laidlaw and Drew. Reviewing results, Whittle redesigned the compressor in line with a revised theory that was independently developed by Griffiths at the RAE at the same time. I think it likely they collaborated. The revised engine was much more successful until destroyed by blade failure on the 9th trial. A combustion problem was allowing over-hot gas into the turbine.

An improved version of the engine ran from the end of 1938 to early 1941, during which time it was updated with an improved combustion chamber developed by Shell. In 1941 a lighter version of the test engine was assembled from spare parts, fitted to a Gloster airframe, and used to test-taxi the aircraft. The engine was not airworthy. They found that the aircraft would not move at all with the turbine at 12000 rpm, and only 20mph at 13000rpm. However, the next day the pilot took the turbine up to 16000 rpm and the plane flew a few feet off the ground for about 200 yards. Two weeks later the plane had been fitted with an airworthy engine and achieved 370mph at 25000 feet, faster than any other fighter aircraft in the world at the time. By 1941 many 'big names' were involved in jet engine development: Rolls Royce, Metropolitan-Vickers, RAE, Armstrong-Siddeley, Bristol and the Americans.

The popular view is that Whittle was a lone wolf who developed the Jet Engine engine despite the RAF. I'm very suspicious of this because he received considerable support from the Royal Aircraft Establishment who – at the same time – had other cards in play. In 1937, before the Whittle engine was tested, Hayne Constant of the RAE obtained approval to start development of the Axial Flow Gas-Turbine, today the most common type. He contracted Metropolitan-Vickers to develop the engine having concluded that the Whittle engine was only suitable for short-range fighters. The engine that powered the prototype Meteor was made by Metropolitan-Vickers, not Whittle. But I don't think the Vickers or Gloster projects would have started without Whittle's 1930 Patent. He energised the issue whilst war-clouds gathered. It was also the first time theory and materials like heat resistant steel were sufficiently advanced to make it possible to build a light powerful efficient engine reliable enough to fly. Great men, all of them.

Dave

Edit can't spell!

Edited By SillyOldDuffer on 02/12/2017 19:31:11

[SillyOldDufferModerator @sillyoldduffer]

Posted by SillyOldDuffer on 02/12/2017 19:27:22:

First Jet Engine. A little blurred depending on what you define as a 'Jet Engine' but quite a few people involved, including:

• Hero 150BC
• Leonardo da Vinci's Smoke Jack, about 1500, very commonly used to drive roasting spits when cooking was done over an open fire
• Stoltz 1872. Modern form, engine not built until 1900, not successful in an aircraft due to inefficiencies and poor materials.
• Armengaud & Lemale built a 25HP unit around 1901, followed by a 400HP design with a Rateau compressor built by Swiss Brown Bovari. Worked inefficiently due to poor compressor performance and low-quality blades
• Holzwarth in 1905 plus Karavodine and Lorin in 1908 started to develop designs resulting in a 350kW engine in 1923 for the Prussian State Railways and a 5000HP unit for a German Steelworks.
• Coanda 1910. Discovered the 'Coanda Effect' which is the tendency of a fluid flow to stick to a surface. It set fire to his aircraft!
• Small turbine driven superchargers were developed in the 1920s and 1930s by several workers notably Buchi and Moss. Turbo-superchargers increase the power of a piston engine by about 50% and allow the engine to work at high altitude. The work is most significant because it led to the development of heat-resistant steels suitable for turbine blades.
• A large Process Gas Turbine was developed by Brown Bovari in 1936 for use in petroleum cracking. It's success led Brown Bovari to later develop the first gas turbine powered generator and the first locomotive powered only by a gas turbine.

Whittle was inspired by work due to Lorin. Whittle deserves full credit for his 1930 patent describing a turbo-jet intended for use in an aircraft. The patent was a considerable advance on earlier work and it was fairly obvious that Whittle's ideas were practical. The patent appears to have kick-started military funded projects in at least Germany (von Ohain) and Italy. In Germany the Heinkel Hirth HeS3 flew in August 1939. The flight was not a success and development of the engine was transferred to BMW and Junkers. In Italy the Caproni-Campini CC2 with a Lorin based engine flew for about 10 minutes in August 1940, again not very successfully. (A year later the aircraft had a top-speed of less than 200mph).

Whittle's first engine ran in 1937 and had compressor, turbine and combustion chamber issues. Whittle designed the compressor and turbine and the combustion chamber was designed by Laidlaw and Drew. Reviewing results, Whittle redesigned the compressor in line with a revised theory that was independently developed by Griffiths at the RAE at the same time. I think it likely they collaborated. The revised engine was much more successful until destroyed by blade failure on the 9th trial. A combustion problem was allowing over-hot gas into the turbine.

An improved version of the engine ran from the end of 1938 to early 1941, during which time it was updated with an improved combustion chamber developed by Shell. In 1941 a lighter version of the test engine was assembled from spare parts, fitted to a Gloster airframe, and used to test-taxi the aircraft. The engine was not airworthy. They found that the aircraft would not move at all with the turbine at 12000 rpm, and only 20mph at 13000rpm. However, the next day the pilot took the turbine up to 16000 rpm and the plane flew a few feet off the ground for about 200 yards. Two weeks later the plane had been fitted with an airworthy engine and achieved 370mph at 25000 feet, faster than any other fighter aircraft in the world at the time. By 1941 many 'big names' were involved in jet engine development: Rolls Royce, Metropolitan-Vickers, RAE, Armstrong-Siddeley, Bristol and the Americans.

The popular view is that Whittle was a lone wolf who developed the Jet Engine engine despite the RAF. I'm very suspicious of this because he received considerable support from the Royal Aircraft Establishment who – at the same time – had other cards in play. In 1937, before the Whittle engine was tested, Hayne Constant of the RAE obtained approval to start development of the Axial Flow Gas-Turbine, today the most common type. He contracted Metropolitan-Vickers to develop the engine having concluded that the Whittle engine was only suitable for short-range fighters. The engine that powered the prototype Meteor was made by Metropolitan-Vickers, not Whittle. But I don't think the Vickers or Gloster projects would have started without Whittle's 1930 Patent. He energised the issue whilst war-clouds gathered. It was also the first time theory and materials like heat resistant steel were sufficiently advanced to make it possible to build a light powerful efficient engine reliable enough to fly. Great men, all of them.

Dave

Edit can't spell!

Edited By SillyOldDuffer on 02/12/2017 19:31:11

[John RuddParticipant @johnrudd16576]

" cant spell"

Boveri……

Yeah nit picking…..

Edited By John Rudd on 02/12/2017 19:51:57

[Ian PParticipant @ianp]

Posted by John Rudd on 02/12/2017 19:50:45:

" cant spell"

Boveri……

Yeah nit picking…..

Edited By John Rudd on 02/12/2017 19:51:57

Nit Nit Picking

can't or cannot

cant is something else, (noun)

Edited By Ian P on 02/12/2017 20:11:04

[Phil WhitleyParticipant @philwhitley94135]

It is also known that Whittles 1930 patent was circulated throughout Europe, including the technical college where Von Ohain was studying, and later taught and did research. As far as I can tell, whittles was the first patent that went on to be a working engine. In the case of most inventions, there are people all over the world working on the same problems, first to the patent office wins, but as can be seen in the above list, first patent is not always first inventor.

[richardandtracyParticipant @richardandtracy]

Don't forget the earlier Tesla Disc turbine. I have forgotten the dates, but 1908 rings a bell.

Regards

Richard

[Author]

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