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Naval Academy Reinstates Teaching of Celestial Navigation
HughPickens.com writes: At the US Naval Academy in Annapolis, midshipmen studied celestial navigation for more than a century -- until 1998, after a decision that came after months of discussion that began with a 1996 curriculum review. Midshipmen were relieved. Celestial calculations were painfully difficult, requiring a nautical almanac and volumes of tables. Now Tim Prudente reports at the Capital Gazette that the Navy has reinstated the teaching of celestial navigation in the manual issued two months ago. The first midshipmen to receive training were juniors during this past summer school. Future classes will learn theories of celestial navigation during an advanced navigation course. And the Class of 2017 will be the first to graduate with the reinstated instruction.
But is there really any point in knowing how to navigate by the stars in a world of GPS? "In the event that we had to go into a national emergency, we would probably have to shut the GPS down because it can be used by potential enemies," says retired Navy Capt. Terry Carraway. "We went away from celestial navigation because computers are great," says Lt. Cmdr. Ryan Rogers, the deputy chairman of the academy's department of seamanship and navigation. "The problem is, there's no backup."
But is there really any point in knowing how to navigate by the stars in a world of GPS? "In the event that we had to go into a national emergency, we would probably have to shut the GPS down because it can be used by potential enemies," says retired Navy Capt. Terry Carraway. "We went away from celestial navigation because computers are great," says Lt. Cmdr. Ryan Rogers, the deputy chairman of the academy's department of seamanship and navigation. "The problem is, there's no backup."
Why wouldn't the military just turn their encryption keys back on so that they can use it but others get worse data? I do agree that teaching your officers celestial navigation is important, but when shit hits the fan, it will be interesting to see which ones actually retain it and can use it without constant practice.
They're not doing this in case they have to turn off the GPS. They're doing this because they realize that the enemy may be able to turn off the GPS (along with everything else that relies on modern microelectronics).
Astro-inertial navigation is old tech for missiles. There's no reason that someone couldn't slap together a similar system as backup for guiding a ship in lieu of GPS. That's not what this is about. This is about weeding dumb people out of the Naval Academy.
It's been done - some nuclear missiles had star-based navigation systems for mid-course corrections, as did the SR-71.
However, it's still a good idea to have people who can do it manually, because anything that will take out GPS has a good chance of taking out your computers as well. It doesn't even have to be a common thing - a dozen people on a ship crewed by five thousand is enough.
On a pitching, rocking ship in the middle of the sea, with a sky that may have cloud coverage so you don't have much choice in the stars that you can shoot? A picture of the sky tells you very little - you need the angle of the celestial object relative to the local horizon. A good human navigator might be able to shoot a few stars through a hole in 9/10ths cloud coverage and get a fix.
Star-trackers work well in space because the platform is relatively stable and you don't have any clouds (usually). Apollo 13 had problems with its star tracker after the explosion because of a cloud of reflective debris around the ship. They had to do a manual burn sighting the Earth's terminator through the reticle.
Not saying a computer couldn't be designed to do it, but getting a robust cel-nav system for sea vessels that can handle the noisy environment that is the sea and sky will be a challenge. Humans still beat computers in some things, this is one of them.
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On the 1991 cruise I was on when in the Navy, our ship's GPS went out. No way to fix it. We had to use compasses and star charts till we got to Pearl Harbor so it could be fixed. If the guys hadn't been trained for it, we'd have been screwed.
What if the issue is not lack of GPS but lack of electrical power? Or, in the case of an EMP, the computers are scrambled? In the time it takes you to work out the issues with the electronics you can also have some people trying to figure out where you are by celestial navigation. That means less down time.
Also, how do you know the computers aren't lying to you? In a sophisticated attack the navigation may not be down but merely rendered inaccurate. Having celestial navigation as an aid means you should be able to correct for electronic navigation errors more quickly.
Also, electronic navigation may only provide one or two points in a triangulation. To complete your triangle of points one might want to know something as simple as which way is north. Reading a compass might seem trivial to you but for some young sailor fresh out of the academy that might not be trivial. Add to that some basics of dead reckoning and just some theory on celestial navigation then we have someone that can get back into the fight more quickly than a sailor ignorant of these things.
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Analog instruments in a typical aircraft "six pack" are quite useful when in the air but mostly useless if floating on water. About the only useful instrument of those would be the magnetic compass. These instruments are also only useful in getting a rough position in the air, close enough to get within visual or radio range of an airport. When on the water one's visible distance is greatly diminished, and in a time of war one might not want to broadcast their position with a radio.
Also, who says that the USNA does not also teach how to use instruments similar to that on an aircraft? I expect that they do. I suspect that those are also just as fragile as GPS in a time of war. Celestial navigation is cheap, readily available, and impossible to "jam", so long as you know how to do it.
You might think it "utterly retarded" but people smarter than both of us disagree with you.
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On the 1991 cruise I was on when in the Navy, our ship's GPS went out. No way to fix it. We had to use compasses and star charts till we got to Pearl Harbor so it could be fixed. If the guys hadn't been trained for it, we'd have been screwed.
Exactly. Tech can fail or be disabled, either deliberately or due to enemy action. Remember how Russia was testing their GPS jamming tech against the US a few years ago in the middle east, by providing it to one of the countries we fought? Similarly, Iran used GPS to bring down a drone. Our guys need to be able to get by without it and, for that matter, to confirm that the computer is right.
It's not like we're requiring every enlisted man to know this stuff--but the officers on a ship of war should damn well know how to navigate by the stars if they have to.
Not if you have a "sun stone". The Vikings used them a few years before I was born. Yeah, I'm that old.
First off you should never completely trust your computers. What happens if a software bug or a hardware problem occurs and says your 10 nautical miles west from where you really are? Not likely but still always good to check to make sure that your systems are running correctly.
The other reason is what if something happens to your ship and you have to abandon it before a distress call could be sent. Quite possible in times of war. You would want to know how to locate where you are so you could paddle the raft in the right direction (if you had a map or knew the location of land) or had some form of communication.
Do you really think military hardware is that fragile? It's built to withstand a close by nuclear explosion. Really, a Navy ship is very, very robust.
As an avid backpacker, I'm amazed how often recent enthusiasts I've come across have little or zero/map and compass skills. Sure, your GPS on your iPhone and hiking app are great, IF you have power, and if it's accurate. But if you lose it, break it, battery dies, then what?
I still travel with Trails Illustrated maps (or other topo maps) and a compass whenever I'm in the backcountry.
I think the Naval Academy made the right decision.
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Allow me to introduce you to the ships gyro. Also referred to as a stable element.
It's the reference plane the fire control systems utilize while plotting a firing solution for the ships guns.
Some of the older manned directors also referenced them and kept the director perfectly stable even in rough seas. Was the best place to be in the event you and the pitching seas didn't get along :)
Assuming it's cloudy, you're GPS systems just went down, all radio navigation aids are lost, and all your compasses were demagnetized, then, yes, I assume one could say they are fucked.
One solution to this problem is like what reboot246 says in a sister post, have a sun stone as part of the celestial navigation gear. Another is to sail into a best guess of a safe direction until one can see a point of reference, be it a celestial object or terrestrial one.
Celestial navigation is not supposed to solve all navigation problems. What it is supposed to do is reduce the reliance on GPS to the point that should it go down you don't have a navy full of ships that can't so much as steer towards a safe harbor.
Having talked with people that sailed at sea, both for pleasure and for the US Navy, every ship has a number of readily available means to navigate. GPS is typically the primary means. Second on the list is likely to be radio navigation of one type or another. Third is typically dead reckoning. If you know where you were, what direction you are heading, and at what speed, you can usually keep sailing with relative safety and ease until you can restore one or the other means of electronic navigation. Those knowledgeable of celestial navigation can go without the electronic navigation for much longer and still reach their destination as scheduled. If it's cloudy while you are without electronic navigation aids then, yes, you will most likely arrive behind schedule.
In war you may not have the luxury of reaching your destination late.
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Back in '72, when I was in the Navy, one of my friends was a Quartermaster's Mate. (Bridge crew, navigation, that kind of thing.) Most of the navigation was done by LORAN, but they still regularly used celestial navigation both to keep in practice and as a backup. And, they still had two different, hand-wound chronometers as the official time source for navigation. The ship used (I think.) steam turbines for propulsion, but we could still navigate if all the electric power was down, or the LORAN equipment was damaged by wind, wave or enemy action.
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When I was learning Celestial Navigation, there were two sets of 'Almanacs' we had to use. One was the Nautical Almanac which gave the positions of the stars, the Sun and the Moon for each minute of each day of the year. These were issued every year by some National Observatory. The other set was just a cookbook of spherical trigonometry. Obviously you can program any modern calculator with the appropriate trig formulas so the Midshipmen would not have to waste time looking up those numbers in the books. I am pretty sure that with modern memory you could put the entire almanac for the year on a USB stick, and so you would not need to look up those numbers either. Add the two together and you can have a rugged, solar powered device that can do the calculations for you. Now all you need to do is get out your sextant and clock, take the sights, plug in the time, the readings and the corrections, and let the pocket calculator do the grunt work.
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Celestial navigation was taught in our Naval Science Navigation course. As naval bridge officers, we were required to learn celestial navigation primarily as tradition and to have a working understanding of the mechanics of the process. That being said, one must know where the ship is at all times. Today, we rely on GPS, inertial navigation systems and the gyroscopic compass (as opposed to a magnetic compass). There have been times when we lost GPS or LORAN C while at sea. We did experience loss of the gyroscopic compass in the middle of ocean and our ship didn't have INS. You have a mission to carry out and that entails safely navigating your vessel.
Basic skills such as dead reckoning and visual position fixes are used when near land. At sea, with no landmarks, knowing where you is just as important. Case in point is that there is an underwater mountain in the Pacific that ships still manage to hit. Avoiding those things is pretty important. Murphy's law will ensure that your ship fill find the underwater mountain or shoal waters if you aren't prepared.
Do navigators take celestial fixes every night the skies are clear? No. They do it from time to time to keep the traditions alive. And, should the skills ever be needed, they will have them. The calculations are tedius and no where as accurate as GPS fix. But, it's an interesting exercise and a time honored tradition.
Mind you, there's a significant difference between hitting a satellite orbiting at slightly more than 300 miles up, and hitting one that's 11,000 miles up.
A lot of the low-earth orbit satellites - which includes some reconnaissance satellites - are vulnerable to common fighter-launched ASATs, but hitting something in geosynchronous orbit is a bit more difficult. It would take large ground-based rockets to reach that altitude, and you would have to launch at least six to disrupt the GPS system over a particular area (and even then, the results would be only temporary as the network can compensate for some losses). Even ICBMs aren't powerful enough to reach them; you would need liquid-fueled rockets that need to be fueled up prior to launch (you don't just keep that stuff sitting around in the rocket's gas tank indefinitely) prior to launch, so your preparations would be very visible and very vulnerable. GPS satellites are also traveling at more than 10,000mph, which makes them a tricky target to hit, so you'll likely need to launch more than one rocket per satellite to ensure a successful interception.
It's not impossible but it is difficult and probably more costly in resources than it is worth.
I'm an officer for the Royal Canadian Navy. I've spent time on the bridge of some of our American friends' warships and it's sometimes a white-knuckle experience. Sailing into northern waters away from large constellations of GPS satellites can easily bring your dilution of precision to the point where you could be almost anywhere, and yet many of my American friends didn't even know what the reading meant on their display. HDOP would be flashing red on the bridge and they would be all fat and happy sailing at full speed. ECPINS put a dot on the electronic chart as to where they were, so that meant that's where they are.
It was with puzzlement that I first learned that Americans didn't teach celestial navigation to its officers. It's not that celestial navigation by itself is really all that necessary, because yes, even without it, there are other methods. But the training of it produces officers that have a better understanding of when their machines are lying to them. It, and all the related skills you need to learn to make it work, gives more useful things in your toolbox to draw from. Because I will tell you from experience, it is not a matter of if a GPS will give you a wrong answer. It's a matter of when.
It's also, if you ask me, not a matter of if but when a shooting war finally breaks out. And if and when it does, you can guarantee that one of the first priorities for the enemy will be to deny NATO (one way or the other) the use of GPS.
Perhaps with a renewed focus on training techniques that don't rely on toys, the USN will stop having the most collision-dented ships in NATO.
Navigation will be the last of your worries then.
Being up shit creek and all I had was a paddle I'd think that knowing where I was would be the first concern.
Let's gather the situation here. Communication is down, weapons down to .50 M2 and small arms, no GPS, no power. Since the ship is likely steam or gas turbine powered the crew should still be able to get the ship to move. I presume as well that there are crew that are injured. This crew is also going to be in need of food, heat, and shelter. I'd think that what a wise captain would want to do is head for the nearest safe harbor for repairs. At a minimum getting to port would mean the crew can find food, heat, and shelter until the ship is repaired or they can be picked up in another.
Given that situation what should a captain do? Head to safe harbor, right? Okay then, to get there they will have to be able to at a minimum know which direction to sail. With a watch, compass, and charts one can do wonderful things. With a sextant and the knowledge to use it, miracles can be performed.
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In the middle of the North Atlantic what is there to hit?
That's exactly what the captain of the Titanic said!
Thank you Sir! Very well said. I am a 68 year old American engineer (retired) who learned his craft using a slide rule and trig tables. During my career I worked with almost every type of computer from Analog behemoths to microprocessors and the one thing I learned is that COMPUTERS WILL LIE TO YOU. You just have to know a bit more than they do to catch them at it.
Also, I wonder if this move is not so much about just loss of GPS but loss of a lot of our electronic infrastructure due to Electromagnetic Pulse, whether man made or from natural events on the Sun. I know of engineers in the US currently working with some of our electric power companies to make contingency plans for such an event. Should we expect any less of the Navy?
"In the event that we had to go into a national emergency, we would probably have to shut the GPS down because it can be used by potential enemies," says retired Navy Capt. Terry Carraway.
Now granted, what you mention might be another reason to reteach celestial navigation. But you are flat wrong in your suggestion that they are not doing this in case they need to turn it off.
When the military discusses in public what they would do in times of enemy action, take it with a grain of salt, yes? It's not their job to accurate describe their plans to their enemies.
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