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Navy Uses Railgun To Launch Fighter Jet

samzenpus posted more than 3 years ago | from the quick-launch dept.

The Military 314

Phoghat writes "In 2015 the aircraft carrier USS Gerald R. Ford will take to the seas and the plan is to use a railgun to launch planes, instead of steam powered catapults. From the article: 'The Navy developed its Electromagnetic Aircraft Launch System as a replacement for the steam catapults currently used on aircraft carriers. The EMALS is a linear induction motor that's capable of accelerating a 100,000 pound aircraft to 240 miles per hour in the space of 300 feet. Compared to a steam catapult, the railgun catapult is much smaller, more efficient, simpler to maintain, gentler on airframes, and can deliver up to 30% more power. It's also capable of being cranked down a whole bunch, meaning that it can also launch smaller (and more fragile) unmanned drones.'"

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First psot (-1, Troll)

Hognoxious (631665) | more than 3 years ago | (#34648830)

Eaten by wolves. It was delicious.

A linear induction motor is not a railgun. (5, Informative)

John Hasler (414242) | more than 3 years ago | (#34648846)

n/t

Re:A linear induction motor is not a railgun. (2, Interesting)

icebike (68054) | more than 3 years ago | (#34648874)

Same accelerator concept though. Maybe what they have built is flexible enough to handle both roles.

Linear induction motor that's capable of accelerating a 100,000 pound aircraft to 240 miles per hour in the space of 300 feet.

One wonders how is that any easier on the airframe?

Anyone know how you calculate G-forces in this kind of acceleration?

Re:A linear induction motor is not a railgun. (4, Insightful)

blackraven14250 (902843) | more than 3 years ago | (#34648890)

I would guess it's easier on the airframe because it can have a different acceleration curve. I imagine a steam driven catapult as having high power at the onset, but lower power at the end, while an electronic method like this can have a more gradual push.

Re:A linear induction motor is not a railgun. (3, Interesting)

Pharmboy (216950) | more than 3 years ago | (#34648928)

I also wonder if it is simply a smoother curve, with less bumps and jarring. This would seem to be much better for a controlled acceleration, not just at G force or final speed, but for the entire range in between. With steam, it would seem they just pushing it at full throttle for the whole distance.

Re:A linear induction motor is not a railgun. (1)

noidentity (188756) | more than 3 years ago | (#34649038)

In other words, constant acceleration, so that there are the same G-forces on the airframe during the entire run, rather than more at the beginning than end.

Re:A linear induction motor is not a railgun. (4, Interesting)

Brett Buck (811747) | more than 3 years ago | (#34649222)

Perhaps. But depending on the capacity of the steam reservoir - which is presumably huge on a nuclear aircraft carrier - the pressure drop is almost certainly negligible. What the motor permits (just looking at the performance aspects) is the acceleration curve to be tailored to the airplane.

Re:A linear induction motor is not a railgun. (5, Informative)

kindbud (90044) | more than 3 years ago | (#34649336)

Perhaps. But depending on the capacity of the steam reservoir - which is presumably huge on a nuclear aircraft carrier - the pressure drop is almost certainly negligible.

It's not. I've manned the steam generator control station on an aircraft carrier, and the drop in water level and steam pressure is dramatic and it takes several minutes to recover. Of course, we had 16 steam generators on the USS Enterprise in the 80's. Perhaps the newer carriers with just 4 steam generators (2 per reactor) are more efficient. But I do recall flight ops were a very very busy time for the MMs in the hole.

This looks like a big improvement. Electricity generation is a much closer to a steady-state kind of operation for a naval nuclear power plant.

Re:A linear induction motor is not a railgun. (-1, Flamebait)

Anonymous Coward | more than 3 years ago | (#34648894)

Same accelerator concept though. Maybe what they have built is flexible enough to handle both roles.

Linear induction motor that's capable of accelerating a 100,000 pound aircraft to 240 miles per hour in the space of 300 feet.

One wonders how is that any easier on the airframe?

Anyone know how you calculate G-forces in this kind of acceleration?

The same way you calculate G-forces in any other kind of acceleration, dumbass.

Did you imagine that there are separate equations for G-forces caused by gasoline engines, diesel engines, jet engines, and railguns? No. G-force is purely a matter of meters per second per second. Acceleration. That is all. Next time don't comment if you don't know what the fuck you're talking aboot and a 10-second Google search would easily answer it. It's a total waste of bandwidth. Dumbass.

Re:A linear induction motor is not a railgun. (-1)

Anonymous Coward | more than 3 years ago | (#34648932)

Amen! Someone mod this shit up!

Re:A linear induction motor is not a railgun. (3, Interesting)

fuzzyfuzzyfungus (1223518) | more than 3 years ago | (#34649068)

While the question could have been phrased better, it isn't as simple as you make it out to be.

You know that the starting velocity is zeroish(maybe a little bit of taxiing; but negligible) and that the end velocity is 240mph; this makes calculating average acceleration over those 300 feet trivial; but it doesn't much help you in determing the actual shape of the acceleration/time graph.

It is quite possible, for instance, that an electrical system has a nearly perfectly constant acceleration, while getting the same out of a steam driven system(whose volume is presumably changing continuously) would be some fairly tricky plumbing.

From an airframe maintenance perspective, I assume that it is the sharp spikes of peak acceleration that cause the most trouble, and those are what a system capable of neatly constant acceleration could avoid...

Re:A linear induction motor is not a railgun. (4, Informative)

BitterOak (537666) | more than 3 years ago | (#34649370)

You know that the starting velocity is zeroish(maybe a little bit of taxiing; but negligible) and that the end velocity is 240mph; this makes calculating average acceleration over those 300 feet trivial;

Actually, it doesn't. Average acceleration is defined as the change in velocity divided by the time interval over which the velocity changes: a_avg = delta v / delta t. The problem here is that you aren't given delta t, but rather the distance through which the jet accelerates. Now, if you know the acceleration is constant, it is easy to calculate the acceleration by means of the formula v_f^2 = v_i^2 + 2a delta x, but for non-constant acceleration, delta t over a fixed distance will depend on the shape of the acceleration curve. Therefore the average acceleration will also depend on the shape of the curve.

Re:A linear induction motor is not a railgun. (1)

elfprince13 (1521333) | more than 3 years ago | (#34649136)

Not really. Acceleration with non-zero jerk will involve different calculations than constant acceleration. There's a reason Hooke's law isn't the first thing they teach you in a high school physics class. The physical interpretation of the calc

Re:A linear induction motor is not a railgun. (1)

Antimatter Beam Core (1892512) | more than 3 years ago | (#34648946)

Same accelerator concept though. Maybe what they have built is flexible enough to handle both roles.

No it isn't.
A rail gun uses two charged rails and a conductive projectile. The projectile is introduced between the rails, strikes an arc, and and is propelled down the barrel by Lorentz force.
A linear induction motor, on the other hand, uses coils to produce magnetic fields which propel the projectile.
Rail guns require maintenance to their rails every few shots, or they will become too eroded to use. Plus, they need another type of gun to start the projectile moving, or you just weld the projectile to the rails. All these factors make a linear induction motor a much better choice for aircraft launch.

Linear induction motor that's capable of accelerating a 100,000 pound aircraft to 240 miles per hour in the space of 300 feet.

One wonders how is that any easier on the airframe?

Anyone know how you calculate G-forces in this kind of acceleration?

The Nimitz class aircraft carriers' steam catapults already do the same thing.

Re:A linear induction motor is not a railgun. (1)

Hognoxious (631665) | more than 3 years ago | (#34648998)

Yeah, I was wondering what advantages this has over steam. Maybe it's easier to route cables than pipes? On the other hand, you're already producing steam for the engines and steam pipes don't short when they get wet.

Re:A linear induction motor is not a railgun. (2)

wiredlogic (135348) | more than 3 years ago | (#34649028)

They are switching to the linear motors for the reliability. Steam catapults need extensive maintenance on a regular basis which cuts down on the available capacity to launch planes

Re:A linear induction motor is not a railgun. (1)

noidentity (188756) | more than 3 years ago | (#34649058)

The electromagnets use insulated wire where it matters. Anywhere there isn't insulation, a little water would vaporize if it were conducting any significant portion of the energy running through the couls.

Re:A linear induction motor is not a railgun. (4, Informative)

Wyatt Earp (1029) | more than 3 years ago | (#34649094)

A lot fewer moving parts and better control over the stroke energy

Looks like they've done over 220 test fires of this already in 2010

http://www.navair.navy.mil/NewsReleases/index.cfm?fuseaction=home.view&id=4468 [navy.mil]

http://en.wikipedia.org/wiki/Electromagnetic_Aircraft_Launch_System#Advantages [wikipedia.org]

Re:A linear induction motor is not a railgun. (2)

John Hasler (414242) | more than 3 years ago | (#34649156)

I was wondering what advantages this has over steam. Maybe it's easier to route cables than pipes?

Much easier.

On the other hand, you're already producing steam for the engines

They are producing steam for the generators that produce electricity for the engines.

...steam pipes don't short when they get wet.

The Navy has been using large electrical machines on shipboard for over 100 years. I think they know how to keep seawater out of them.

Re:A linear induction motor is not a railgun. (4, Interesting)

kindbud (90044) | more than 3 years ago | (#34649402)

They are producing steam for the generators that produce electricity for the engines.

Are you sure about that? Isn't the Gerald Ford one of the Nimitz class carriers? Those have steam turbines to turn the screws. ...after Wikipedia lookup...

Nope, it's the first of a new class. How about that. Last time I saw an electric motor turning a screw was at prototype training following nuclear power school.

Damn! They're going to launch it with systems installed that only use half the available generating capacity. They expect to be able to put lasers on it in the future and have the juice to fire them. Sci Fi is no longer Fi.

Re:A linear induction motor is not a railgun. (2)

apoc.famine (621563) | more than 3 years ago | (#34649484)

If you've got seawater on your flight deck, there's a pretty good chance you're not launching airplanes off it...

Re:A linear induction motor is not a railgun. (3, Informative)

afidel (530433) | more than 3 years ago | (#34649458)

The advantage is they are building in massive electrical generation and distribution into this generation of carrier. They are looking forward to railgun and solid state laser point defense systems to replace the current CIWS which is thought to be outclassed by today's best surface skimming missiles and will surely be outclassed during the 50+ year horizon for the class. Add in reduced maintenance and increased availability during peak operating times (all jets scramble) and you have an easy sell. It's also much easier to patch a damaged electrical system, all you need is the right gauge spare cable and a few tools. With a steam system you have to find the leak (no TDR) and patch it to a high pressure steam fight finish, a much more difficult task.

Re:A linear induction motor is not a railgun. (2)

0100010001010011 (652467) | more than 3 years ago | (#34648966)

Jerk [wikipedia.org] is probably what you should look at, not acceleration.

Re:A linear induction motor is not a railgun. (1)

krygny (473134) | more than 3 years ago | (#34648982)

... Anyone know how you calculate G-forces in this kind of acceleration?

No details provided but I'd assume you can vary the current with a high degree of [computer] control. Increasing the inertia gradually, rather than an instantaneous kinetic release of steam.

Re:A linear induction motor is not a railgun. (3, Informative)

GloomE (695185) | more than 3 years ago | (#34649000)

v = 400km/h = 111m/s
s = 100m

v^2 = 2as

a = v^2/2s

a = 12321/200

a = 61m/s^2

g = 9.8m/s^2

a = 6.3g

Re:A linear induction motor is not a railgun. (1)

jklovanc (1603149) | more than 3 years ago | (#34649174)

This calculates the average acceleration over the distance. What if the acceleration is not constant. As has been stated by another poster, steam catapults accelerate better at the start than at the end. What if the initial acceleration was 8.3g at the start and linearly declined to 4.3G at the end. The final velocity would be the same and the average acceleration would be the same but the stress on the aircraft and pilot would be higher.

Another poster touched on a valid point about jerk. Nothing instantaneously goes from at rest to 6.3g acceleration. There is a small space in time that the acceleration changes. By controlling that transition stress on the airframe and pilot is reduced.

Re:A linear induction motor is not a railgun. (5, Informative)

Anonymous Coward | more than 3 years ago | (#34649042)

Same accelerator concept though.

No, it is not. It is far more similar in concept to a mass driver.

A railgun consists of two parallel, electrically conductive rails, each connected to one terminal of a charge storage device (usually a capacitor, but if you've got something better, go with it). The charge storage device is charged to full power, and then a conductive projectile is placed across the rails, completing a circuit.

The completed circuit resembles a large inductor, in that it is a large conductive loop with current flowing through it, whose inductance is proportional to the area enclosed by the loop. The magnetic field generates a force upon all the components of the railgun, but since the projectile is the only part not rigidly fixed, it is moved by the force. The force acts to increase the size of the inductive loop, driving the projectile away.

The key component to note here is that the projectile needs to be conductive, not ferromagnetic, and the rails must be exposed in order to pass current. This limits military applications because the presence of dirt in the rails could break the circuit, causing an electric arc flash, causing the system to act more like an arc welder. Also, the rails wear out due to the heating caused by the lack of superconductivity.

Read the Wikipedia articles for Railgun and Mass Driver more details.

Re:A linear induction motor is not a railgun. (0)

Anonymous Coward | more than 3 years ago | (#34649072)

Anyone know how you calculate G-forces in this kind of acceleration?

First you metricise: 240 m/h ~= 107 m/s , 300 feet ~= 91 m. First assume Uniform acceleration (probably not, but then g is constant during the acceleration).

Then for some math, solving the time over which this takes place: s(displacement)=0.5(u(inital speed)+v(end speed))t -> 91=0.5(0+107)t t ~=1.68s

Then solve the acceleration: s(displacement)=0.5a(acceleration)t(time)^2 -> 91=0.5a(1.68^2) -> a~=63.6 m*s^-2
1 g is approx 9.8 m*s^-2 so dividing by these yields it in g-forces: approx 6.49g

Re:A linear induction motor is not a railgun. (1)

LetterRip (30937) | more than 3 years ago | (#34649138)

One wonders how is that any easier on the airframe?

Anyone know how you calculate G-forces in this kind of acceleration?

It isn't the total acceleration, it is the change in acceleration (jerk) that stresses the airframe. The steam catapult has a lot of jerk, the induction system can minimal jerk.

Re:A linear induction motor is not a railgun. (1)

MattskEE (925706) | more than 3 years ago | (#34649158)

Same accelerator concept though. Maybe what they have built is flexible enough to handle both roles.

No, they're not the same concept, and the electromagnetic plane launcher that they are building here cannot readily be re-purposed as a railgun.

The EMALS [navy.mil] (electromagnetic air launch system) is a Linear Induction Motor which works just like a standard AC motor except it has been laid out flat instead of in a circle. The launch carriage has a set of alternating magnetic poles (the stator) and it is driven by a series of series of coils which are driven with the appropriate AC waveform as the carriage passes overhead.

A Railgun [wikipedia.org] contains no permanent magnets, it uses a current through the projectile (or through a projectile carrier) to create a Lorentz force with the current in the rails which propels the projectile.

In principle one could attempt to design a linear induction motor as a weapon, but since the point of a railgun is to achieve extremely high exit velocity (current Navy efforts have achieved on the order of 2.5km/s, shooting for 5km/s) it will be very challenging to achieve the appropriate rise/fall times in the driving coils. The need for permanent magnets in the projectile are also a problem, and I imagine there would be issues with magnetic fields saturating the projectile unless the magnitudes are limited, meaning the weapon must be longer.

I could see a role for LIM directly as a weapon only if there were some application where you need to launch a relatively very heavy projectile at relatively small exit velocity.

Re:A linear induction motor is not a railgun. (2)

John Hasler (414242) | more than 3 years ago | (#34649188)

The EMALS [navy.mil] (electromagnetic air launch system) is a Linear Induction Motor...

Actually, it's a linear synchronous motor.

Re:A linear induction motor is not a railgun. (1)

MattskEE (925706) | more than 3 years ago | (#34649202)

>The EMALS [navy.mil] (electromagnetic air launch system) is a Linear Induction Motor...

Actually, it's a linear synchronous motor.

Right you are, thanks for the correction. A linear induction motor would actually be closer to a railgun, although still not quite there.

Re:A linear induction motor is not a railgun. (1)

MorePower (581188) | more than 3 years ago | (#34649246)

Cooool! How do you put field current into the, um, rotor? (carriage, I guess)? I guess metal wheels would work.

Re:A linear induction motor is not a railgun. (1)

nospam007 (722110) | more than 3 years ago | (#34649210)

"I could see a role for LIM directly as a weapon only..."

It fires armed airborne bomb/missile launchers, sounds like a weapon to me.

Re:A linear induction motor is not a railgun. (2)

fluffy99 (870997) | more than 3 years ago | (#34649256)

"I could see a role for LIM directly as a weapon only..."

It fires armed airborne bomb/missile launchers, sounds like a weapon to me.

Actually they are developing railguns for launching projectiles and weapons. If the weapon doesn't need to have a chemical propellant it makes it much smaller and you can carry a lot more. All electric propulsion is being worked on as well. This is all part of the larger Navy initiative towards all-electric ships. Electricity is cheap and plentiful when you have up to 8 reactors onboard.

As a side note, the Navy did a study for converting smaller ships to nuclear instead of oil. The cross-over point for total cost of ownership/operations was at $140/barrel for oil.

Re:A linear induction motor is not a railgun. (1)

afidel (530433) | more than 3 years ago | (#34649478)

I could see a role for LIM directly as a weapon only if there were some application where you need to launch a relatively very heavy projectile at relatively small exit velocity.

I wonder if you could get a LIM up to enough velocity to launch shore bombardment shells? Then again I'm not sure enough electro-chemical storage for such a system would be any less dangerous than a powder magazine if it should be hit =)

Re:A linear induction motor is not a railgun. (0)

Anonymous Coward | more than 3 years ago | (#34649076)

Yeah, had to laugh / call bullshit as soon as I read the first sentence. If it were a railgun launcher you'd maybe see part of the front wheel go shooting down the runway at mach 5, but the rest of the plane wouldn't go anywhere and just fall over nose down.

Re:A linear induction motor is not a railgun. (-1)

Anonymous Coward | more than 3 years ago | (#34649298)

How about I use a beef gun to launch my semen at your tonsils?

Very cool (2)

O('_')O_Bush (1162487) | more than 3 years ago | (#34648848)

Now they only need a more efficient way of catching the planes when they land.

Re:Very cool (2)

radish (98371) | more than 3 years ago | (#34648908)

I'm imagining a giant electro magnet.... :)

Re:Very cool (1)

nanospook (521118) | more than 3 years ago | (#34648970)

Jello..

Re:Very cool (1)

Mordie (1943326) | more than 3 years ago | (#34649008)

200 kilos of ferrous + 1 sabot + 1 300f launcher = very very big gun

Re:Very cool (1)

Anonymous Coward | more than 3 years ago | (#34649070)

Now they only need a more efficient way of catching the planes when they land.

According to wikipedia, It will have an electromagnetic arresting system to stop the planes. See http://en.wikipedia.org/wiki/USS_Gerald_R._Ford_(CVN-78)#Launch_systems

Re:Very cool (4, Interesting)

reaper (10065) | more than 3 years ago | (#34649098)

When I was working on the arrestor portion in 2001, we had a system controlling two linear induction motors attached to the arrestor cable. Turns out that yes, you can use this type of system to stop planes, it is effective in many situations where planes come in at odd angles (the system pulls the plane towards the center of the deck), and you can recover power from it.

However, if you wire the position encoders backwards, the motor cores eject quite violently as soon as the control system is turned on. Thankfully, interns are surprisingly good at dodging.

Interns are surprisingly good at dodging. (-1)

Anonymous Coward | more than 3 years ago | (#34649328)

Thankfully, interns are surprisingly good at dodging.

Re:Very cool (1)

Centurix (249778) | more than 3 years ago | (#34649412)

As with some other technologies, I think they could take a hint from nature. In particular the frog where we fit-out every air-craft carrier with a giant sticky tongue which shoots out when the plane gets within striking distance.

Rail Gun Weld (1)

Anonymous Coward | more than 3 years ago | (#34648856)

Isn't one of the problems with railguns that sometimes the projectile will weld itself to the rail? What happens if that occurs with a jet launcher on the rail, and a plane hooked to that?

Re:Rail Gun Weld (2)

osu-neko (2604) | more than 3 years ago | (#34648886)

Isn't one of the problems with railguns that sometimes the projectile will weld itself to the rail?

Only at sufficient speeds/friction. There's no reason a railgun-based aircraft launcher would be more prone to this problem than a steam-based one.

What happens if that occurs with a jet launcher on the rail, and a plane hooked to that?

Same thing that happens now if the thing gets stuck.

Re:Rail Gun Weld (5, Informative)

Rakishi (759894) | more than 3 years ago | (#34649110)

Only at sufficient speeds/friction. There's no reason a railgun-based aircraft launcher would be more prone to this problem than a steam-based one.

As I understand the issue, it has nothing to do with friction. In fact it's probably more likely to get welded if it's going too slowly.

A rail gun is basically an arc welder in a way, you're passing massive amount of energy in the form of electricity through the interface between the rails and projectile. A high power rail gun has enough energy passing through to basically vaporize nontrivial amounts of metal off the rails every time it's fired. If you're unlucky on the other hand it'll simply weld the projectile to the rails.

Re:Rail Gun Weld (2)

Nefarious Wheel (628136) | more than 3 years ago | (#34649450)

As I understand the issue, it has nothing to do with friction. In fact it's probably more likely to get welded if it's going too slowly.

A rail gun is basically an arc welder in a way, you're passing massive amount of energy in the form of electricity through the interface between the rails and projectile.....

Think of a long, overpowered Jacob's Ladder with a slug where you'd expect the expanding arc.

Re:Rail Gun Weld (4, Informative)

causality (777677) | more than 3 years ago | (#34648918)

Isn't one of the problems with railguns that sometimes the projectile will weld itself to the rail? What happens if that occurs with a jet launcher on the rail, and a plane hooked to that?

As another poster pointed out [slashdot.org] , this technically isn't a railgun. It's a linear motor. This is more like a mag-lev train. The other big advantage is that in a real railgun, the rails need frequent replacement.

If you were expecting technical accuracy from our esteemed professional Slashdot editors, that day has not yet arrived. They're still trying to figure out how to work a spell-checker and how to use basic English grammar. As long as the ad revenues and the paid account revenues keep on flowing, I suppose they don't feel much pressure to get these things right.

Re:Rail Gun Weld (0)

Anonymous Coward | more than 3 years ago | (#34649378)

Specifically, it's a linear synchronous motor.

After all, a railgun is also a linear motor, specifically a linear homopolar motor.

Really, though, this goof isn't particularly disappointing; it seems like everyone gets railguns wrong, so at least the editors have an excuse. However, they routinely pass far more obvious errors...

Re:Rail Gun Weld (0)

Anonymous Coward | more than 3 years ago | (#34648926)

This is not a rail gun. It's a plain old electric motor in linear form.

Re:Rail Gun Weld (1)

Nefarious Wheel (628136) | more than 3 years ago | (#34649428)

Isn't one of the problems with railguns that sometimes the projectile will weld itself to the rail? What happens if that occurs with a jet launcher on the rail, and a plane hooked to that?

The pilot is in for a short, yet highly interesting flight.

Space Flight? (1)

bl4nk (607569) | more than 3 years ago | (#34648902)

I've always wondered, why haven't electromagnets been utilized for escaping Earth's atmosphere? It's cheaper and more

Re:Space Flight? (1)

cheater512 (783349) | more than 3 years ago | (#34649116)

Rockets output power evenly over the entire take off. Electromagnets need a structure around the projectile to continue propelling it but there is no way to make it that tall.

Re:Space Flight? (1)

Nefarious Wheel (628136) | more than 3 years ago | (#34649470)

Rockets output power evenly over the entire take off. Electromagnets need a structure around the projectile to continue propelling it but there is no way to make it that tall.

You don't need "tall". You can make do with a straight, horizontal structure tangent to the planetary (or lunar) sphere. You have to punch through more atmosphere (if from the Earth, and let's not talk about noise ordinances), but you can certainly achieve orbit from a horizontal electronic accelleration structure. From the Moon, no-brainer. Less structure, make it longer. As long as it's straight enough at the muzzle you'll get your escape velocity.

Re:Space Flight? (2)

fuzzyfuzzyfungus (1223518) | more than 3 years ago | (#34649134)

The concept has been advanced; but my understanding is that(beyond the capital costs of building a gigantic magnetic accelerator) there are issues, for most payloads because of the incredible acceleration needed.

A rocket enjoys continuous thrust, so it can be relatively leisurely about reaching escape velocity. A magnetically accelerated pod has only the length of its accelerator track(and, unless you want that track to be very short or very expensive, you are likely launching at an angle other than vertical, thus travelling through more atmosphere to reach orbit). This means that your accelerator pod ends up pulling some hundreds of Gs for a few seconds, which cuts down on the sort of payloads you can launch. Water? sure. Food? some forms. Crew? only if you like meat paste...

Re:Space Flight? (4, Interesting)

Nyeerrmm (940927) | more than 3 years ago | (#34649258)

Don't forget fuel. The least 'sci-fi' way to really open up the solar system is to use something like railguns to get fuel (and water too) to orbit for cheap, and get the crew and food to orbit using cheap things like the Dragon/Dream Chaser/Orion Lite capsules.

Most of the Saturn V stack was fuel. If we can get a reliable on-orbit refueling infrastructure in place, you could launch a moon landing on a Saturn I and do it easily within the current NASA budget. No heavy lift needed.

Re:Space Flight? (1)

Albinoman (584294) | more than 3 years ago | (#34649270)

If you want a space launch vehicle capable of escape velocity, that's 11,200m/s. The space shuttle is about 3Gs or 9.8*3=29.4m/s^2. It would take just under 6 1/2 minutes at that acceleration and needs a rail over 1,300 miles long! Now the problem is you are pointing at the horizon. No sudden turns at 7mi/s.

Couldn't wedge an "I" in there? (2)

RyuuzakiTetsuya (195424) | more than 3 years ago | (#34648916)

"Dear Gaddafi, I sent you some EMAILS. I hope you get them."

-- President Sarah Palin.

Carrier stumbles over chair, 1000's Embarresed (2, Funny)

Usagi_yo (648836) | more than 3 years ago | (#34648920)

USS Gerald R. Ford? You have to be kidding me. What's next. USS Chevy Chase?

Re:Carrier stumbles over chair, 1000's Embarresed (1)

ilo.v (1445373) | more than 3 years ago | (#34648980)

USS Gerald R. Ford? You have to be kidding me. What's next. USS Chevy Chase?

They wanted to name one after Bush, but they didn't want it to look bad. Solution: name a different one after Gerald.

Re:Carrier stumbles over chair, 1000's Embarresed (2)

rossdee (243626) | more than 3 years ago | (#34649018)

They did name one after Daddy Bush though. (And fair enough because he did fight in WWII in the Navy. Carter got a sub named after him because he was a sub captain.

Re:Carrier stumbles over chair, 1000's Embarresed (1)

DesScorp (410532) | more than 3 years ago | (#34649054)

They did name one after Daddy Bush though. (And fair enough because he did fight in WWII in the Navy. Carter got a sub named after him because he was a sub captain.

There's a great political cartoon that came out when the Carter was commissioned... "An attack submarine???".

Re:Carrier stumbles over chair, 1000's Embarresed (4, Informative)

LWATCDR (28044) | more than 3 years ago | (#34649120)

Carter was never a sub captan. He served on a submarine but was not a commander.
Actually the shouldn't have named the sub after Jimmy Carter or the Carrier after Bush. It is tradition that no Navy ship is named after a living person. It was broken by the Burke class. It was unintentional because it takes so long to design a new ship that the Navy was sure that Burke would have passed on by the time the Burke was launched. He lived to a very ripe old age and mess up tradition.
There is no reason to not name a ship after a President of the US and what most people don't know is that Gerald R. Ford was actually a very good president under considering what he had to work with. He as also a very good and honorable man as politicians go. I don't think you can find a single blemish on his record and historians today say his pardon of Nixon was the right thing to do.

Re:Carrier stumbles over chair, 1000's Embarresed (1)

Col. Klink (retired) (11632) | more than 3 years ago | (#34649334)

> Ford was actually a very good president under considering what he had to work with.

Yeah! I mean, unless you consider the fall of Saigon or "Whip It Now" failures...

I'd say his greatest achievement was picking Stevens for the Supreme Court. But that only worked out so well because Stevens utterly betrayed Ford.

Re:Carrier stumbles over chair, 1000's Embarresed (0)

Anonymous Coward | more than 3 years ago | (#34649454)

Yep, he was the best president to never appear on a presidential ballot.

Re:Carrier stumbles over chair, 1000's Embarresed (1)

Wyatt Earp (1029) | more than 3 years ago | (#34649152)

Jimmy Carter left the navy as a Lieutenant, he didn't command a submarine but was part of the nuclear engineering department of USS Seawolf SSN-575

Re:Carrier stumbles over chair, 1000's Embarresed (2)

ilo.v (1445373) | more than 3 years ago | (#34649224)

They did name one after Daddy Bush though ... fair enough because he did fight in WWII in the Navy.

My apologies, I assumed everyone would know that, but you are right, we should explain that here.

In the US Navy's defense, they do have a "theme" where many aircraft carriers are named after U.S. Presidents:

USS John F Kennedy
USS Dwight D Eisenhower
USS Thodore Roosevelt
USS Abraham Lincoln
USS George Washington
USS Harry S. Truman
USS Ronald Reagan
USS George H.W. Bush
USS Gerald R. Ford

"Daddy Bush" was indeed a real honest-to-god carrier pilot, and actually did real honest-to-god fighting. He had already been admitted to Yale, with the war time draft deferment to go with it, but joined the Navy instead. He became the Navy's youngest pilot. He was shot down while bombing a Japanese radio tower on Chichi Jima, winning the Distinguished Flying Cross. (His plane was hit and on fire but he finished his bombing run first before bailing out).

My not so funny joke was pointing out that things were going to get a lot less defensible if they continued to follow the calendar and named the next two after Clinton and Baby Bush. (See, ma, bipartisan dissing!)

Re:Carrier stumbles over chair, 1000's Embarresed (1)

ilo.v (1445373) | more than 3 years ago | (#34649244)

Oops, missed one:

USS Franklin D. Roosevelt CV 42

Re:Carrier stumbles over chair, 1000's Embarresed (0)

Anonymous Coward | more than 3 years ago | (#34648994)

Only after someone elects Chevy president.

Re:Carrier stumbles over chair, 1000's Embarresed (0)

Anonymous Coward | more than 3 years ago | (#34649036)

http://en.wikipedia.org/wiki/USS_George_H.W._Bush

Re:Carrier stumbles over chair, 1000's Embarresed (5, Informative)

DesScorp (410532) | more than 3 years ago | (#34649040)

USS Gerald R. Ford? You have to be kidding me. What's next. USS Chevy Chase?

Trust me, many Navy vets (including this one, who served on a carrier) are tired of the Navy naming our biggest capital ships after politicians. Layups like George Washington or Thomas Jefferson, no problem. But Gerald Ford? Really? There's a feeling in the Navy that we should stick to traditional names.... the Essex, the Hornet, the Lexington, etc, for our most prominent ships. But don't look for this practice to end, because appealing to political egos helps grease the Congressional appropriation machine.

Re:Carrier stumbles over chair, 1000's Embarresed (1)

binaryseraph (955557) | more than 3 years ago | (#34649460)

Could be worse... Just wait for the USS Jimmy Carter!

Re:Carrier stumbles over chair, 1000's Embarresed (1)

Mt._Honkey (514673) | more than 3 years ago | (#34649528)

The USS Jimmy Carter already exists, as an attack submarine. wikilink [wikipedia.org]

Re:Carrier stumbles over chair, 1000's Embarresed (3, Interesting)

Wyatt Earp (1029) | more than 3 years ago | (#34649128)

You know that Gerald Ford had a naval career right? He lead a fire control team that saved the escort carrier USS Monterey.

Ford, Carter and George H.W. Bush all had naval careers, both Ford and Bush were on carriers and have carriers named for them, Carter was in the submarine service and has a submarine named for him.

Re:Carrier stumbles over chair, 1000's Embarresed (-1)

Anonymous Coward | more than 3 years ago | (#34649338)

You know that Gerald Ford had a naval career right? He lead a fire control team that saved the escort carrier USS Monterey.

Ford, Carter and George H.W. Bush all had naval careers, both Ford and Bush were on carriers and have carriers named for them, Carter was in the submarine service and has a submarine named for him.

Isn't the Navy full of fags? I mean they can call it "hot bunking" all they want. All they want. It's still two men. Sleeping. In one bed. It goes on even when not strictly necessary. 'Nuff said amirite?

The USS Gerald R. Ford was sunk today (1)

riker1384 (735780) | more than 3 years ago | (#34649286)

The aircraft carrier Gerald Ford was sunk today, and eaten by a pack of senseless sea-wolves. It was delicious.

Elcromagnetic (0)

Anonymous Coward | more than 3 years ago | (#34648958)

But how does it work?

Re:Elcromagnetic (0)

Anonymous Coward | more than 3 years ago | (#34649106)

I don't know. The scientific personnel were upsetting me.

But why have a catapult at all? (1)

Colonel Sponsz (768423) | more than 3 years ago | (#34649044)

What I'm curious about is why they're using catapults at all - the Russians [wikimedia.org] and the Brits [wikimedia.org] , for example, use a "ski jump" instead. And I read somewhere (unfortunately, I can't remember where - damn you, source blindness!) that that approach is actually better, in terms of aircraft launch rate, as you don't have a complex catapult system that has to be reset for every plane.

So... why are US carriers using catapults, when they seem to me to be just another point of failure? Can someone enlighten me?

Re:But why have a catapult at all? (2)

Spy Handler (822350) | more than 3 years ago | (#34649090)

because US Navy needs to launch large aircraft with significant payload (unlike the brits or russians)

Re:But why have a catapult at all? (1)

Anonymous Coward | more than 3 years ago | (#34649114)

Only special airplanes can take off using a ski jump. The airplane must be built for short takeoff, which forces compromises elsewhere. The jump itself doesnt give the plane any airspeed at all, it just helps give it an upward vector. With a catapult you can launch a wide variety of more conventional airplanes because the catapult gives them the airspeed needed for flight.

Re:But why have a catapult at all? (4, Insightful)

icegreentea (974342) | more than 3 years ago | (#34649150)

The maximun launch weight on pure ski-jump systems are much much lower than catapult launches. The old British carriers for example were stuck launching Sea Harriers which had a max take off weight of 12000kg. The F-18 (the original one... they've all been replaced by heavier planes) had an EMPTY weight just 1000kg less than that. It's max take off weight from a US Carrier was almost over twice that of the Sea Harrier.

The new British carriers (suppose to launch Eurofighter variant) will also have a catapult.

The catapult is another point of failure. That's one reason there's 4 on a ship. And that's reason why US had an advantage. They had an unbroken string of experience designing, building, and maintaining catapult systems since the end of WW2.

Re:But why have a catapult at all? (0)

Anonymous Coward | more than 3 years ago | (#34649154)

US Carrier aircraft tend to be heavier than most other currently operating naval aircraft. CATOBAR (catapult launch and arrested recovery) allows that, while ski jumps or vertical takeoff, which is the alternative, does not. This allows Navy carrier aircraft to perform about as well as land based planes, which things like a harrier do not. Don't expect to see something like an F-18 with a significant number of bombs or a lot of fuel take off from a ski jump- it can't do it. I would expect that whatever the Russians are flying off of their carriers has either a short range or a very light payload. The advantages of the CATOBAR aircraft are significant enough that the Royal Navy is going to build two carriers with catapults in the near future so they can operate them.

Re:But why have a catapult at all? (5, Informative)

LWATCDR (28044) | more than 3 years ago | (#34649162)

Yes because cats are a better solution.
You can launch heavier aircraft with a cat than with a ski jump. The Russians and UK can not operate aircraft like the E-2. Also the UK is going to put cats on their latest carrier because the F-35b may fail.
Also a Ski jump can not launch while the carrier as at a stop which can be useful.

So yes the sky jump has one benefit but a lot of drawbacks. The Russians used them because it was a low risk for their first real carrier. The brits used them because they only had the Harrier. It did work very well for the Harrier but the Harrier was not as good of a fighter as the F-14 or F-18. It also was not as good of an attack aircraft as the F-18, A-6, or A-7. But it was better than nothing.

Re:But why have a catapult at all? (5, Informative)

jklovanc (1603149) | more than 3 years ago | (#34649322)

Where fighter and bombers get all the glory there are a few equally important heavy aircraft that need catapults to launch:

AEW:
Aircraft such as the the E-2 Hawkeye http://en.wikipedia.org/wiki/Northrop_Grumman_E-2_Hawkeye [wikipedia.org] are critical to hiding the location of the fleet. If the enemy sees a ship based radar they know where the ship and usually the fleet is. If they see an airborne radar the fleet could be very far away. Also airborne radar can see further.

COD;
Carier Onboad Delivery, Need those critical parts or personel delivered outside of helicopter range? Need to evacuate critically injured personnel? You need a long range aircraft to do it.

Tankers;
Need to extend range to a target? Need to loiter for long periods on CAP. Need a sip of fuel to get back to the carrier because you used to much afterburners in the fight? Tankers are your friend. This role is currently done in the US Navy by the F/A-18E/F http://en.wikipedia.org/wiki/F/A-18E/F_Super_Hornet#Tanker_role [wikipedia.org]

Without catapults none of these aircraft would get off the deck.

Steam Power for the Win (1)

gnapster (1401889) | more than 3 years ago | (#34649052)

I am immensely tickled to hear that steam power is still being used in some modern context, even if I only learn of it as it is being phased out. I had never realized that this was how aircraft carrier slingshots worked. Are there any other interesting uses of steam power these days, outside of electricity production?

Re:Steam Power for the Win (1)

Kral_Blbec (1201285) | more than 3 years ago | (#34649272)

Its the bread and butter of hospital sterilization, but i dont know how interesting that is.

Re:Steam Power for the Win (1)

Timothy Brownawell (627747) | more than 3 years ago | (#34649410)

Steam turbines are basically the way to turn an external heat source into mechanical energy. Typically this is just used to generate electricity since it's so much more convenient to work with, but for a few applications the turbine will be attached directly to something other than a generator (say, a propeller on a big boat). Steam can also be used even more directly; as a heat source / heat transfer mechanism (say, for heating groups buildings particularly in colder climates), for cleaning carpets, for sterilizing things, in industrial chemical processes, apparently as a replacement for liquid water in some kinds of modern clothes-washing machines, ... .

Sure whatever (0)

Anonymous Coward | more than 3 years ago | (#34649124)

This is mega old news. I'm sure I did exactly this in Roller Coaster Tycoon.

Of course, those carts full of people didn't fly quite as well as I'd expect a proper fighter jet would.

is it 13 g's or are my calculations off? (0)

Anonymous Coward | more than 3 years ago | (#34649300)

I haven't done this in decades but here's the calculations as best as I can remember. Ahhh physics in customary units and fractions, enjoy:

vi = 0
vf = 240 mph = 352 ft/s
dx = 300 ft

dv = vf - vi

dt = dx / dv
dt = ( 300 ft ) / ( 352 ft/s )
dt = 75/88 seconds

a = dv / dt
a = ( 352 ft/s ) / ( 75/88 s )
a = ( 30976 / 75 ft/s^2 )

approximately 413 ft/s^2 or about 13 G's

Re:is it 13 g's or are my calculations off? (1)

GreenTom (1352587) | more than 3 years ago | (#34649366)

I think you're off by a factor of 2: dt = dx / (average V). Since it goes from 0 to 352 ft/s, v-bar is 176 ft/s, and dt is 75/44 sec.

Anyone been to Cedar Point? (1)

GreenTom (1352587) | more than 3 years ago | (#34649304)

The amusement park in Ohio? They've got a roller coaster [wikipedia.org] that uses the same technology to launch, and it's pretty incredable. There are also a few [wikipedia.org] rides [wikipedia.org] in other parks that use liner induction motros to basically fling you straight up...I havent had a chance to ride those, but I imagine that's about as close most of us will get to a carrier fighter launch. Riding Maverick is what made me realize that being a figher pilot must be kind of like trying to use a computer while riding a roller coaster.

Re:Anyone been to Cedar Point? (1)

NekSnappa (803141) | more than 3 years ago | (#34649392)

Actually it's more like taking a physics exam, programming you GPS, and talking on the phone. All while driving a Formula 1 car.
And since we're talking about carrier based planes here. Imagine that you stop the car by catching the axels on a cable while going full speed.

Quake (1)

timestride (1660061) | more than 3 years ago | (#34649330)

But can it be used for headshots?

Oh please, gundams have been using them for years. (1)

BobSixtyFour (967533) | more than 3 years ago | (#34649512)

Old news, time to join us in the Cosmic Era/Universal Century time standards :)

Fighters - Railguns (1)

LongearedBat (1665481) | more than 3 years ago | (#34649518)

Fighters of the future...
We use railguns to shoot them up.
We use railguns to shoot them down.
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