ISF Logo   IS Forum
Forum Index Register Members List Events Mark Forums Read Help

Go Back   International Skeptics Forum » General Topics » Science, Mathematics, Medicine, and Technology
 


Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.
Tags aircraft

Reply
Old 10th June 2019, 09:52 PM   #201
Trebuchet
Penultimate Amazing
 
Trebuchet's Avatar
 
Join Date: Nov 2003
Location: The Great Northwet
Posts: 21,541
I've a vague recollection of driving through Seattle many years ago and seeing a Sea Dart being hoisted over a fence to the Museum of Flight, then in development and not open yet. It probably wasn't.
__________________
Cum catapultae proscribeantur tum soli proscripti catapultas habeant.
Trebuchet is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 04:40 AM   #202
Dave Rogers
Bandaged ice that stampedes inexpensively through a scribbled morning waving necessary ankles
 
Dave Rogers's Avatar
 
Join Date: Jan 2007
Location: Cair Paravel, according to XKCD
Posts: 29,018
Originally Posted by smartcooky View Post
Anyone know what this one is?

https://www.dropbox.com/s/4qdfa43hro...0.28.jpg?raw=1


I caught a glimpse of this on a History Channel programme about the Battle of Britain. I don't recall seeing anything looking like this in that battle.
Any chance of uploading the image to ISF? For complicated reasons completely unconnected with goofing off at work I can't view Dropbox links.

Dave
__________________
Me: So what you're saying is that, if the load carrying ability of the lower structure is reduced to the point where it can no longer support the load above it, it will collapse without a jolt, right?

Tony Szamboti: That is right
Dave Rogers is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 05:41 AM   #203
Norman Alexander
Philosopher
 
Norman Alexander's Avatar
 
Join Date: Nov 2014
Posts: 5,477
Originally Posted by Captain_Swoop View Post
Don't forget the Shackleton, some of those had contra rotating props but like the Gannet they are turboprop, not piston engines.
IIRC, the Avro Shackleton was the end of the design line that started with the Avro Manchester, then the Lancaster, then the Lincoln.




__________________
...our governments are just trying to protect us from terror. In the same way that someone banging a hornets’ nest with a stick is trying to protect us from hornets. Frankie Boyle, Guardian, July 2015

Last edited by Norman Alexander; 11th June 2019 at 05:43 AM.
Norman Alexander is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 06:46 AM   #204
Giordano
Penultimate Amazing
 
Join Date: Apr 2011
Posts: 15,594
Most of the British WW2 bombers I've seen tend to be boxy (and I know the American B-24 was too). Even had boxy noses and windscreens. Isn't this the opposite of streamlining and didn't it take away from speed and range? What was the main advantage? Ease of construction? I though perhaps it enhanced interior space but I believe a cylinder has the max internal volume per surface area (being a pulled out sphere).

They certainly were successful.
Giordano is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 06:47 AM   #205
Giordano
Penultimate Amazing
 
Join Date: Apr 2011
Posts: 15,594
Originally Posted by Pope130 View Post
You have only to ask. This is the Red Baron Mustang. A modified P-51D with the Rolls Royce Griffon and contra-rotating props.
I can only imagine how noisy it must be.
Giordano is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 10:29 AM   #206
Captain_Swoop
Penultimate Amazing
 
Captain_Swoop's Avatar
 
Join Date: Jun 2010
Posts: 20,797
Originally Posted by Giordano View Post
Most of the British WW2 bombers I've seen tend to be boxy (and I know the American B-24 was too). Even had boxy noses and windscreens. Isn't this the opposite of streamlining and didn't it take away from speed and range? What was the main advantage? Ease of construction? I though perhaps it enhanced interior space but I believe a cylinder has the max internal volume per surface area (being a pulled out sphere).

They certainly were successful.
It allows a bigger bomb bay and proper nose and tail turrets.

Lancaster
Max speed 282 mph at 13,000 ft
Cruise speed: 200 mph Range: 2,530 mi
Bomb load 14,000 lb or a single 22,000 lb Grand Slam with modifications to bomb bay


Flying Fortress
Max speed 287 mph at 13,000 ft
Cruise speed: 182 mph
Range: 2,000 mi with 6,000 lb
Bomb load 8,000 lb or 4,500 on a long range mission
Captain_Swoop is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 10:46 AM   #207
jimbob
Uncritical "thinker"
 
jimbob's Avatar
 
Join Date: Jan 2007
Location: UK
Posts: 20,707
Originally Posted by Giordano View Post
Most of the British WW2 bombers I've seen tend to be boxy (and I know the American B-24 was too). Even had boxy noses and windscreens. Isn't this the opposite of streamlining and didn't it take away from speed and range? What was the main advantage? Ease of construction? I though perhaps it enhanced interior space but I believe a cylinder has the max internal volume per surface area (being a pulled out sphere).

They certainly were successful.
There's volume, and there's usable volume. The two are often different.
__________________
OECD healthcare spending
Expenditure on healthcare
http://www.oecd.org/els/health-systems/health-data.htm
link is 2015 data (2013 Data below):
UK 8.5% of GDP of which 83.3% is public expenditure - 7.1% of GDP is public spending
US 16.4% of GDP of which 48.2% is public expenditure - 7.9% of GDP is public spending
jimbob is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 10:52 AM   #208
Aber
Graduate Poster
 
Join Date: Apr 2011
Posts: 1,442
Originally Posted by Captain_Swoop View Post
It allows a bigger bomb bay and proper nose and tail turrets.
IIRC the design specification included a requirement to carry 2 torpedoes, giving a very long bomb bay.

Last edited by Aber; 11th June 2019 at 10:54 AM.
Aber is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 12:35 PM   #209
COLONEL
Sniper of the Galactic Universe
 
COLONEL's Avatar
 
Join Date: Nov 2006
Location: The many voids of the Universe
Posts: 17,694
Originally Posted by MRC_Hans View Post
OK, here is one. While it says "Danish Experimental" on this one, the general type was built in several places. The idea was the common man's aircraft. A single seater with an engine of about 30hp, it was not aimed for the higher parts of the sky. It was meant to be easy to fly, having only three controls:

- Rudder
- The angle of the main wing
- Throttle

They could fly, but as already the Brothers Wright found out, you really cannot do without ailerons: There are simply too many situations you cannot get yourself out of, and indeed several of these things crashed. Now they sit in museums here and there.

Hans
I saw something similar to this on the Smithsonian channel , It was a home built with a snowmobile engine
__________________

Major Ashley-Pitt: In our experience, Americans are uncouth misfits who should be run out of their own barbaric country. Matthew Quigley: Well, Lieutenant...
Major Ashley-Pitt: Major. Matthew Quigley: Major. We already run the misfits outta our country. We sent 'em back to England.
COLONEL is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 12:39 PM   #210
Jack by the hedge
Safely Ignored
 
Jack by the hedge's Avatar
 
Join Date: Oct 2009
Posts: 9,503
As I recall, the tall narrow front profile of the Halifax allowed a full-sized front turret, but it was only when that was deleted in favour of a simpler perspex nose and the aerodynamics cleaned up that the Halifax gained the speed and ceiling to operate with the other 4-engined bombers.
Jack by the hedge is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 01:07 PM   #211
Norman Alexander
Philosopher
 
Norman Alexander's Avatar
 
Join Date: Nov 2014
Posts: 5,477
See if you can tell why this was a rare kite: Avro Lancaster B.II.

__________________
...our governments are just trying to protect us from terror. In the same way that someone banging a hornets’ nest with a stick is trying to protect us from hornets. Frankie Boyle, Guardian, July 2015
Norman Alexander is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 01:13 PM   #212
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Posts: 22,079
Originally Posted by Norman Alexander View Post
See if you can tell why this was a rare kite: Avro Lancaster B.II.

https://cdn-live.warthunder.com/uplo...6b6460fc88.jpg
Hercules radial engines. There was a huge demand for Merlins, and especially before Packard started building them in the US on license, they were in short supply. So they made a version with the radials. Incidentally, that version performed nicely.

Hans
__________________
Experience is an excellent teacher, but she sends large bills.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 01:16 PM   #213
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Posts: 22,079
Originally Posted by COLONEL View Post
I saw something similar to this on the Smithsonian channel , It was a home built with a snowmobile engine
Some used the Citročn 2CV engine (two cylinder boxer, aircooled, about 500cc, in a car it yielded about 18 hp, but without muffler and cooling fan, I suppose it could have made 25).

Drove several of the cars in my time.

Hans
__________________
Experience is an excellent teacher, but she sends large bills.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 01:23 PM   #214
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Posts: 22,079
Originally Posted by Captain_Swoop View Post
It allows a bigger bomb bay and proper nose and tail turrets.

Lancaster
Max speed 282 mph at 13,000 ft
Cruise speed: 200 mph Range: 2,530 mi
Bomb load 14,000 lb or a single 22,000 lb Grand Slam with modifications to bomb bay


Flying Fortress
Max speed 287 mph at 13,000 ft
Cruise speed: 182 mph
Range: 2,000 mi with 6,000 lb
Bomb load 8,000 lb or 4,500 on a long range mission
One reason for the seemingly inferior performance of the B17 was its far heavier defensive armament, up to 13 cal 50 machine-guns. The Lanc had far less and relied on operating at night.

Hans
__________________
Experience is an excellent teacher, but she sends large bills.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 01:32 PM   #215
Norman Alexander
Philosopher
 
Norman Alexander's Avatar
 
Join Date: Nov 2014
Posts: 5,477
Originally Posted by Giordano View Post
Most of the British WW2 bombers I've seen tend to be boxy (and I know the American B-24 was too). Even had boxy noses and windscreens. Isn't this the opposite of streamlining and didn't it take away from speed and range? What was the main advantage? Ease of construction? I though perhaps it enhanced interior space but I believe a cylinder has the max internal volume per surface area (being a pulled out sphere).

They certainly were successful.
The design aims were simple: Maximise bomb load and range per aircraft. Speed and altitude were not major factors. Tonnage delivered was the goal. So they were very basic freighters.

The Lanc was essentially a flying bomb-bay with fuel-tanks for wings. The bomb bay was designed to easily carry a variety of ordnance without needing modification: Mines, napalm, small, medium and large standard design bombs, the various sizes of HC bombs (finless, basically big round canisters), Tallboys and 10-ton Grand Slams (these did require some major aircraft modifications). Even torpedoes could be carried although I don't think they ever were.

It was not until the much bigger US B-29 went into action that the US had an equivalent bomber. It was bigger, faster and flew higher for a longer range - a very new and modern breed of aircraft. But it still had a slightly less maximum carrying capacity than the Lanc.

Factoid: a Lancaster was initially considered for the atomic raids on Japan as it could definitely lift that size bomb. But it did not have the range or altitude ability needed to get there and survive the blast. It would have been a one-way suicide mission.
__________________
...our governments are just trying to protect us from terror. In the same way that someone banging a hornets’ nest with a stick is trying to protect us from hornets. Frankie Boyle, Guardian, July 2015

Last edited by Norman Alexander; 11th June 2019 at 01:34 PM.
Norman Alexander is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 01:35 PM   #216
Captain_Swoop
Penultimate Amazing
 
Captain_Swoop's Avatar
 
Join Date: Jun 2010
Posts: 20,797
Originally Posted by MRC_Hans View Post
One reason for the seemingly inferior performance of the B17 was its far heavier defensive armament, up to 13 cal 50 machine-guns. The Lanc had far less and relied on operating at night.

Hans
Plus the tiny bomb bay and narrow fuselage.
Captain_Swoop is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 11th June 2019, 02:27 PM   #217
abaddon
Penultimate Amazing
 
abaddon's Avatar
 
Join Date: Feb 2011
Posts: 18,618
Originally Posted by Dave Rogers View Post
Any chance of uploading the image to ISF? For complicated reasons completely unconnected with goofing off at work I can't view Dropbox links.

Dave
Ask and ye shall recieve



Or
Attached Images
File Type: jpg 2019-06-01 16.00.28.jpg (113.7 KB, 3 views)
__________________
Who is General Failure? And why is he reading my hard drive?


...love and buttercakes...
abaddon is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 12th June 2019, 12:55 AM   #218
Dave Rogers
Bandaged ice that stampedes inexpensively through a scribbled morning waving necessary ankles
 
Dave Rogers's Avatar
 
Join Date: Jan 2007
Location: Cair Paravel, according to XKCD
Posts: 29,018
That's definitely a Fulmar; the section of fuselage skin between the front and rear cockpits means it's not a Battle or the P4/34, that's a Merlin not a Griffon so it isn't a Firefly, and the chin radiator is pretty distinctive too.

Dave
__________________
Me: So what you're saying is that, if the load carrying ability of the lower structure is reduced to the point where it can no longer support the load above it, it will collapse without a jolt, right?

Tony Szamboti: That is right
Dave Rogers is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 12th June 2019, 09:08 AM   #219
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Posts: 22,079
Originally Posted by Dave Rogers View Post
That's definitely a Fulmar; the section of fuselage skin between the front and rear cockpits means it's not a Battle or the P4/34, that's a Merlin not a Griffon so it isn't a Firefly, and the chin radiator is pretty distinctive too.

Dave
I agree on the Fulmar, but I'm curious: How can you discern a Merlin from a Griffon on such a fuzzy shot? I know the Griffon is larger, still ...

Hans
__________________
Experience is an excellent teacher, but she sends large bills.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 12th June 2019, 09:22 AM   #220
Dave Rogers
Bandaged ice that stampedes inexpensively through a scribbled morning waving necessary ankles
 
Dave Rogers's Avatar
 
Join Date: Jan 2007
Location: Cair Paravel, according to XKCD
Posts: 29,018
Originally Posted by MRC_Hans View Post
I agree on the Fulmar, but I'm curious: How can you discern a Merlin from a Griffon on such a fuzzy shot? I know the Griffon is larger, still ...
Well, really I suppose it's the difference between the nose shapes of the Firefly and the Fulmar really, but the underside of Griffon installations tends to be a lot less sharply curved than a Merlin, as well as it being noticeably longer.

Dave
__________________
Me: So what you're saying is that, if the load carrying ability of the lower structure is reduced to the point where it can no longer support the load above it, it will collapse without a jolt, right?

Tony Szamboti: That is right
Dave Rogers is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 12th June 2019, 10:25 AM   #221
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Posts: 22,079
Originally Posted by Dave Rogers View Post
Well, really I suppose it's the difference between the nose shapes of the Firefly and the Fulmar really, but the underside of Griffon installations tends to be a lot less sharply curved than a Merlin, as well as it being noticeably longer.

Dave
The Griffon does appear a bit "fatter", but since Fairy designs were generally not very sleek, I wonder if it would show up on the outside. Just the other day had a look at a Firefly (there's one in a Danish museum), and it looks like a tractor compared to a spitfire. Of course, it was meant for a different purpose, but it still comes over as big and clumsy.

Hans
__________________
Experience is an excellent teacher, but she sends large bills.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 13th June 2019, 04:25 AM   #222
Chris_Halkides
Philosopher
 
Chris_Halkides's Avatar
 
Join Date: Dec 2009
Posts: 9,361
Originally Posted by Trebuchet View Post
I've a vague recollection of driving through Seattle many years ago and seeing a Sea Dart being hoisted over a fence to the Museum of Flight, then in development and not open yet. It probably wasn't.
Maybe it was. There was a Sea Dart in Seattle, but it was later moved to Lakeland, FL. "In the last half of the 1960s, YF2Y-1 Sea Dart number 135765 was secured by the Pacific Northwest Aviation Historical Foundation for possible inclusion in the Museum of Flight. This Sea Dart had been at Seattle’s Sand Point Naval Air Station until the museum moved it to the Renton, Washington, airport as seen." BTW Lakeland and Kissimmee are less than 60 miles apart, and that might be the reason why there is some confusion about the location of one of the Sea Darts. Besides Lakeland, there are also Sea Darts in San Diego, CA and Willow Grove, PA.
__________________
“Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing had
happened.” – Winston Churchill

Last edited by Chris_Halkides; 13th June 2019 at 04:32 AM.
Chris_Halkides is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 06:50 AM   #223
Giordano
Penultimate Amazing
 
Join Date: Apr 2011
Posts: 15,594
Does the Lockheed D-21 reconnaisance drone (unmanned, disposable, and originally designed to be launched from the M-21 Blackbird) fit within the OP?
https://en.wikipedia.org/wiki/Lockheed_D-21

Mach >3.3 and operational altitude of 90,000 feet.

Not very successful.

One is in the Museum of Flight in Seattle WA.

Last edited by Giordano; 14th June 2019 at 06:54 AM.
Giordano is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 07:16 AM   #224
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Posts: 22,079
Originally Posted by Giordano View Post
Does the Lockheed D-21 reconnaisance drone (unmanned, disposable, and originally designed to be launched from the M-21 Blackbird) fit within the OP?
https://en.wikipedia.org/wiki/Lockheed_D-21

Mach >3.3 and operational altitude of 90,000 feet.

Not very successful.

One is in the Museum of Flight in Seattle WA.
And made obsolete by satellites.

Hans
__________________
Experience is an excellent teacher, but she sends large bills.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 08:29 AM   #225
3point14
Pi
 
3point14's Avatar
 
Join Date: Nov 2005
Posts: 17,654
Originally Posted by Giordano View Post
Does the Lockheed D-21 reconnaisance drone (unmanned, disposable, and originally designed to be launched from the M-21 Blackbird) fit within the OP? .
Yup.


Originally Posted by MRC_Hans View Post
And made obsolete by satellites.

Hans
I remember (I think) the US having to dig out the old U2s when they realised that you can't just have a satellite stay on station. Has that been solved?
__________________
Up the River!

Anyone that wraps themselves in the Union Flag and also lives in tax exile is a [redacted]
3point14 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 08:33 AM   #226
The Great Zaganza
Maledictorian
 
The Great Zaganza's Avatar
 
Join Date: Aug 2016
Posts: 8,259
I'm going to mention the Boeing X-37 here, because remarkably few people are aware of its existence:

https://en.wikipedia.org/wiki/Boeing_X-37
__________________
Opinion is divided on the subject. All the others say it is; I say it isn’t.
The Great Zaganza is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 09:55 AM   #227
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Posts: 22,079
Originally Posted by 3point14 View Post

I remember (I think) the US having to dig out the old U2s when they realised that you can't just have a satellite stay on station. Has that been solved?
That has to be a myth. First of all, you can (geostationary orbit). Also the trick with spy satellites was (and is) to have them in a low, highly declined orbit, so they will sweep as much of the planet as possible, really fast.

However, the problem at the time of the cold war was the quality of pictures. Transmitting bandwidth from satellites was still rather limited, and the resolution of electronic cameras was low, actually deplorably by our present standards. So it was still used to take analog pictures on film, then have the satellite develop them and either drop them back down on Earth or transmit them by a telefax-like slow scanning method.

- So in certain instances, the U2 might still have been preferable. Especially when not over central enemy territory, so the risk of getting shot down was lower.

Hans
__________________
Experience is an excellent teacher, but she sends large bills.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 10:40 AM   #228
Trebuchet
Penultimate Amazing
 
Trebuchet's Avatar
 
Join Date: Nov 2003
Location: The Great Northwet
Posts: 21,541
Originally Posted by The Great Zaganza View Post
I'm going to mention the Boeing X-37 here, because remarkably few people are aware of its existence:

https://en.wikipedia.org/wiki/Boeing_X-37
And, linked from that article, the NF-104A, which famously nearly killed Chuck Yeager.
__________________
Cum catapultae proscribeantur tum soli proscripti catapultas habeant.
Trebuchet is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 10:48 AM   #229
theprestige
Penultimate Amazing
 
Join Date: Aug 2007
Posts: 35,007
Originally Posted by MRC_Hans View Post
That has to be a myth. First of all, you can (geostationary orbit). Also the trick with spy satellites was (and is) to have them in a low, highly declined orbit, so they will sweep as much of the planet as possible, really fast.
The other reason you want them in a low orbit, rather than geostationary, is because there's an upper limit to the size of the optics you can launch into space. For reconnaissance and espionage, you'll want to those optics to be close up for maximum resolution and detail.
theprestige is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 10:49 AM   #230
Elagabalus
Illuminator
 
Join Date: Dec 2013
Posts: 4,491
Originally Posted by Trebuchet View Post
And, linked from that article, the NF-104A, which famously nearly killed Chuck Yeager.
From your link.

Boeing X-20 Dyna-Soar?

Way to name a plane, Boeing!
Elagabalus is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 10:51 AM   #231
theprestige
Penultimate Amazing
 
Join Date: Aug 2007
Posts: 35,007
Originally Posted by 3point14 View Post
I remember (I think) the US having to dig out the old U2s when they realised that you can't just have a satellite stay on station. Has that been solved?
What is this? I can't even... Do you seriously believe this?

Do you seriously believe that anyone actually involved in aerial or orbital reconnaissance, at any point in the history of those disciplines, was ever under the impression that planes wouldn't be needed because satellites in LEO could hover?

---

I remember (I think) the US ending up keeping U2s in service because sometimes you need a plane and the U2 is often more cost-effective option for aerial reconnaissance than the SR-71.

The SR-71 being a great example of the kind of "peak effectiveness" you get when there's a military need that dismisses cost as a consideration. When it absolutely, positively, has to be photographed right now, in a denied airspace... Use a satellite if you have one coming up. Or use an SR-71. For everything else, there's the U2.

One advantage to aerial reconnaissance is that satellite schedules are known, and peer enemies will schedule their operations to avoid making pretty pictures for the orbital cameras. If they're going to move when the satellites are away, you want to at least be able to get a plane there for coverage while the action is happening.

Last edited by theprestige; 14th June 2019 at 10:57 AM.
theprestige is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 10:52 AM   #232
3point14
Pi
 
3point14's Avatar
 
Join Date: Nov 2005
Posts: 17,654
Originally Posted by MRC_Hans View Post
That has to be a myth. First of all, you can (geostationary orbit). Also the trick with spy satellites was (and is) to have them in a low, highly declined orbit, so they will sweep as much of the planet as possible, really fast.

However, the problem at the time of the cold war was the quality of pictures. Transmitting bandwidth from satellites was still rather limited, and the resolution of electronic cameras was low, actually deplorably by our present standards. So it was still used to take analog pictures on film, then have the satellite develop them and either drop them back down on Earth or transmit them by a telefax-like slow scanning method.

- So in certain instances, the U2 might still have been preferable. Especially when not over central enemy territory, so the risk of getting shot down was lower.

Hans
I have to tell you, I really don't think you're right that satellites make spyplanes/drones obsolete. The U2 is still in service. I'm pretty sure that the US does have global, 24hr satellite coverage and that they like the ability of the U2 to observe a specific area at a specific time which, I believe, cannot always be done by satellite.
__________________
Up the River!

Anyone that wraps themselves in the Union Flag and also lives in tax exile is a [redacted]
3point14 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 10:56 AM   #233
3point14
Pi
 
3point14's Avatar
 
Join Date: Nov 2005
Posts: 17,654
Originally Posted by theprestige View Post
What is this? I can't even... Do you seriously believe this?

Do you seriously believe that anyone actually involved in aerial or orbital reconnaissance, at any point in the history of those disciplines, was ever under the impression that planes wouldn't be needed because satellites in LEO could hover?

No, I was being florid (however, while none of those you list would be unaware of the limitations, I do not have the same confidence that elected officials would grasp the limitations). I do believe, however, that the US authorities, at one point, overestimated the effectiveness of their satellite network and that spyplanes are still an extremely useful thing.

The SR71 was reactivated after it was retired and the U2 is still in service.
__________________
Up the River!

Anyone that wraps themselves in the Union Flag and also lives in tax exile is a [redacted]

Last edited by 3point14; 14th June 2019 at 10:57 AM.
3point14 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 10:59 AM   #234
Trebuchet
Penultimate Amazing
 
Trebuchet's Avatar
 
Join Date: Nov 2003
Location: The Great Northwet
Posts: 21,541
Originally Posted by Chris_Halkides View Post
Maybe it was. There was a Sea Dart in Seattle, but it was later moved to Lakeland, FL. "In the last half of the 1960s, YF2Y-1 Sea Dart number 135765 was secured by the Pacific Northwest Aviation Historical Foundation for possible inclusion in the Museum of Flight. This Sea Dart had been at Seattle’s Sand Point Naval Air Station until the museum moved it to the Renton, Washington, airport as seen." BTW Lakeland and Kissimmee are less than 60 miles apart, and that might be the reason why there is some confusion about the location of one of the Sea Darts. Besides Lakeland, there are also Sea Darts in San Diego, CA and Willow Grove, PA.
Interesting, thanks for that! I'm not so sure that the picture was actually taken in Renton, due to what appears to be the first prototype 747 in the background. I was of the impression that the Renton airport is too small for 747's. I'll have to dig a bit.

ETA: Boeing did operate some 747's to Renton early on, for refurbishment after the flight test program. One landed a bit short and ripped the landing gear off.
__________________
Cum catapultae proscribeantur tum soli proscripti catapultas habeant.

Last edited by Trebuchet; 14th June 2019 at 11:17 AM.
Trebuchet is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 12:53 PM   #235
abaddon
Penultimate Amazing
 
abaddon's Avatar
 
Join Date: Feb 2011
Posts: 18,618
Originally Posted by theprestige View Post
One advantage to aerial reconnaissance is that satellite schedules are known, and peer enemies will schedule their operations to avoid making pretty pictures for the orbital cameras. If they're going to move when the satellites are away, you want to at least be able to get a plane there for coverage while the action is happening.
One can, if required, alter a spy satellites orbit at need to get it where you need it to be. Down side of that is the sat's useful life dwindles rapidly every time such a thing might occur, and there is a delay before you get to the intended result.

Altering a sat's orbit is a big decision. You invalidate it's primary mission, wipe years off it's effective lifespan in a jot and have to repeat the exercise again to get it back on mission. Satellites don't carry a whole bunch of RCS fuel in the first place.

Easier to send a plane if it is urgent.
__________________
Who is General Failure? And why is he reading my hard drive?


...love and buttercakes...
abaddon is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 02:05 PM   #236
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Posts: 22,079
Originally Posted by 3point14 View Post
I have to tell you, I really don't think you're right that satellites make spyplanes/drones obsolete. The U2 is still in service. I'm pretty sure that the US does have global, 24hr satellite coverage and that they like the ability of the U2 to observe a specific area at a specific time which, I believe, cannot always be done by satellite.
Actually it was a specific unmanned supersonic drone we were talking about. The advantage of things like the U2 is to get in in a specific place at a specific time, but at a risk.

Drones are back for that, but an entirely different kind.

Hans
__________________
Experience is an excellent teacher, but she sends large bills.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 03:40 PM   #237
ceptimus
puzzler
 
Join Date: May 2003
Posts: 5,625
Geostationary can only be stationary (relative to a point on the ground) above the equator. You could launch a satellite into a 24-hour circular orbit inclined relative to the equator, but then it would trace out a repeated figure-8 path over the ground going through the crossing point of the 8 above the equator twice per day.

Also, geostationary is about 22,000 miles up, and you don't tend to get very good resolution photos of the ground from that high. Most reconnaissance satellites are in much lower, much faster orbits and pass overhead real fast - so you need a lot of them if you want to get regular updates of what's happening on the ground at one particular location.

Last edited by ceptimus; 14th June 2019 at 03:53 PM.
ceptimus is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 03:48 PM   #238
theprestige
Penultimate Amazing
 
Join Date: Aug 2007
Posts: 35,007
Hence the need for aerial reconnaissance to supplement satellite reconnaissance.
theprestige is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 04:17 PM   #239
smartcooky
Penultimate Amazing
 
smartcooky's Avatar
 
Join Date: Oct 2012
Location: Nelson, New Zealand
Posts: 11,676
Originally Posted by MRC_Hans View Post
That has to be a myth. First of all, you can (geostationary orbit).
No. Satellites in geostationary orbit cannot be used for optical surveillance. They are 36,000 km away from the earths' surface.

The angular size of an object at a distance is calculated by the formula

d / D x 206265 = R

where
d is the actual size of an object in meters
D distance to that object in meters
R is the resulting angular size in arc-seconds

So a 1m object at a distance of 36,000 km is

1/36,000,000 x 206265 = 0.0057 arc-seconds

To put that into perspective, the Hubble Space Telescope (which is equipped with a 2.4m mirror) has a resolution of 0.1 arc-seconds (I have posted the formula and calculations at the bottom of the post)

Hubble is 17.5 times too small to resolve a 1m object from geostationary distance. If it were possible to use Hubble at geostationary distance, its best resolution would show objects smaller than 18m as a single pixel! To put it another way, for a geostationary optical surveillance satellite to resolve a 1m object at ground level, its optical element (mirror or lens) would have to be 42 metres in diameter!!

Originally Posted by MRC_Hans View Post
Also the trick with spy satellites was (and is) to have them in a low, highly declined orbit, so they will sweep as much of the planet as possible, really fast.
Unfortunately the downside is that satellites have to follow orbits, and those orbits are precise, predictable, and cannot be kept secret. This means that the countries you are spying on know precisely when those satellites will be over the installation you are trying to photograph right down to the hours, minutes and seconds, so they can act accordingly. This is what Lockheed Skunk Works at Area 51 knew when they were developing the SR-71/YF-12A (then known as OXCART) while the Soviets were spying on them. They knew not to have the prototypes and testing models outside at certain times of the day. (Even so, they still boobed in a rather amusing way https://news.nationalgeographic.com/...ed-a-12-plane/) *scroll down to "Shadows of Area 51"

Originally Posted by MRC_Hans View Post
However, the problem at the time of the cold war was the quality of pictures. Transmitting bandwidth from satellites was still rather limited, and the resolution of electronic cameras was low, actually deplorably by our present standards. So it was still used to take analog pictures on film, then have the satellite develop them and either drop them back down on Earth or transmit them by a telefax-like slow scanning method.

- So in certain instances, the U2 might still have been preferable. Especially when not over central enemy territory, so the risk of getting shot down was lower.
It doesn't matter how advanced digital imagery gets, the Laws of Physics has limits, and one of those limits is the wavelength of visible light - it requires "X" amount of optical element diameter to get "Y" amount of resolution and there is no way around it.



* * * * * *
Formula and calculation
The theoretical resolution of a telescope is calculated using the formula

R = 11.6 / D

where R is the the angular size of the object in arc-seconds and D is the diameter of the mirror in centimetres. The HST mirror is 2.4 meters (240 cm), so we can calculate that its theoretical resolution is 11.6 / 240 = 0.05 arc-seconds. (For comparison, the diameter of the moon as viewed from the Earth is half a degree, about 1800 arc-seconds

There is a slight problem with this however. Due to factors involving interference patterns and the wavelength range of visible light, the smallest resolvable object is about twice the theoretical resolution. This is given using something called Nyquist's Theorem; you can read about it here.

http://en.wikipedia.org/wiki/Optical..._.28spatial.29

So effectively, the HST's resolution is about 0.1 of an arc-second.
__________________
#THEYAREUS
The Mueller Report must be released to Congress in full - If Trump has nothing to hide, then he should also have nothing to fear!

Last edited by smartcooky; 14th June 2019 at 05:53 PM.
smartcooky is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 14th June 2019, 06:08 PM   #240
Delvo
الشيطان الأبيض
 
Delvo's Avatar
 
Join Date: Jul 2008
Location: Harrisburg, PA
Posts: 7,929
U-2 never got decommissioned & then resurrected. At least into the 1990s, they had been in continuous use since their start, including for some other countries.

SR-71 did get temporarily brought back once. I have the idea stuck in my head that it was for one of the wars in Iraq, but that might be because I know the same thing happened with battleships at that time and the memory leaked over.

It might seem like the simplest solution for surveillance from above would be to just have enough satellites up there that when one gets too far from the subject another gets close enough. A dozen, for example, would be enough to put them only 30° apart from each other, which would put any point on Earth in line of site to 5-6 of them at all times. A low orbit might mean each one zips by in under an hour, but the job can just be handed off to the next one in line. I long presumed that that must be the way it is these days, although not during most of the life spans of U-2 & SR-71. But it turns out that the number and orbits of satellites that we've actually launched haven't been arranged that way. Given that there are lots & lots of other satellites for civilian functions (or both, like GPS) up there, this can't be because better military coverage would cost too much, so I wonder why...
Delvo is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Reply

International Skeptics Forum » General Topics » Science, Mathematics, Medicine, and Technology

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 01:54 PM.
Powered by vBulletin. Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.

This forum began as part of the James Randi Education Foundation (JREF). However, the forum now exists as
an independent entity with no affiliation with or endorsement by the JREF, including the section in reference to "JREF" topics.

Disclaimer: Messages posted in the Forum are solely the opinion of their authors.