Difference b/w Air/Land launched missiles

  • Thread starter sorter
  • Start date
  • Tags
    Difference
In summary: Missiles don't use turbofans, they use turbojets.I've seen long-range missiles with small bypass ratio turbofans.
  • #1
sorter
48
0
Provided that we have got two different missiles by name(A & B) but yet they have in common the guidance system as well as the engine say a turbofan; can they be called a single missile having two versions i.e air launched & land launched??

If not does this mean that though both have turbofans but thrust profiles/specific impulses are different for air & land launched missiles??

I do know that there will be some aerodynamic diffences but what about internal makeup??
 
Physics news on Phys.org
  • #2
If the two missiles, you are talking about, are made by the same company then they can be considered a single missile with two versions.
 
  • #3
Missiles don't use turbofans, they use turbojets.
 
  • #4
I've seen long-range missiles with small bypass ratio turbofans.

Aside from that, they could be, but obviously the start sequences will be different. More importantly though, air and surface-launched missiles typically have different missions, and thus aren't suited for the same missile.

It's difficult enough at times to design for one operating point and condition, let alone two different missions.
 
  • #5
I'd say the biggest difference is a surface launched cruise missile often requires a rocket booster.
 
  • #6
Um... Cyrus, what about Tomahawks? AGM-86? AGM-129? Basically any cruise missile will use a turbofan.
 
  • #7
boneh3ad said:
Um... Cyrus, what about Tomahawks? AGM-86? AGM-129? Basically any cruise missile will use a turbofan.

I thought those were turbojets. Interesting...must be low bypass ratio.
 
  • #8
Low-bypass turbofans. There aren't any turbojets used on any American aircraft these days that I am aware of. I am not even sure if other countries still use them. Even fighters use low-bypass turbofans now. Generally, missiles use either a turbofan or a solid rocket engine depending on their mission.

To answer the original question, you can have the same missile that is capable of both air and sea (and land) launches. For example, the Tomahawk could launched from land or sea (though we no longer use the land version) and was designed to be able to launch from the air if needed. It uses a solid rocket to launch and then the turbofan kicks in regardless of the launch method.
 
  • #9
People I believe ht there must be some difference in thrust profiles of a cruise missile that is launched from a aircraft fling at
1) 1.6Mach
2)~16km altitude

compared to a missile launch from sealevel with 0 initial speed
 
  • #10
sorter said:
People I believe ht there must be some difference in thrust profiles of a cruise missile that is launched from a aircraft fling at
1) 1.6Mach
2)~16km altitude

compared to a missile launch from sealevel with 0 initial speed

Did you see russ' comment in Post #5?
 
  • #11
Some clarifications:
-It isn't typical for cruise missiles to be launched from supersonic aircraft.
-Some cruise missiles use turbojets, notably the Harpoon family: http://en.wikipedia.org/wiki/Boeing_AGM-84_Harpoon
-Supersonic cruise missiles aren't all that common, but tend to use rocket-boosted ramjets.
-Yes, the point of the rocket booster is essentially to boost the cruise missile from a standing start into the the launch envelope (a certain speed and altitude) of the air-launched version. This, of course, requires a high thrust for a short period of time.
 
  • #12
  • #13
The AGM-129 and BGM-109 are different cruise missiles.
 
  • #14
jhae2.718 said:
The AGM-129 and BGM-109 are different cruise missiles.
Manufacturer General Dynamics (initially)
Raytheon Missile Systems
 
  • #15
Just because they have the same manufacturer doesn't make them the same missile. The BGM-109 Tomahawk was originally designed as a submarine launched cruise missile. The AGM-129 was intended to be an LO air launched cruise missile with a nuclear warhead. They are different platforms with different missions.
 
  • #16
AGM-129 is also low-observable and has a significantly longer range but could only be launched from a B-52
 
  • #17
jhae2.718 said:
Just because they have the same manufacturer doesn't make them the same missile. The BGM-109 Tomahawk was originally designed as a submarine launched cruise missile. The AGM-129 was intended to be an LO air launched cruise missile with a nuclear warhead. They are different platforms with different missions.

Tht was my basic confusion of whether should i take thm two different missiles or a single missile wth two variants??
BY THE WAY Do you also believe in that perception that only similarly designed missiles can be called as versions of each others...
 
  • #18
In the case of the two missiles above, they are different. There may certainly be some commonalities; somewhat similar guidance and propulsion systems may be used (why reinvent the wheel, after all?). They may be in the same class of missile, but they are different platforms, IMO.

Now, if you were to compare the sea and air launched versions of the Tomahawk, those would be different variants of the same missile.

Of course, I'm not the person who gets to definitively state these things.
 
  • #19
^^Thnx now I understood.
 
  • #20
russ_watters said:
Supersonic cruise missiles aren't all that common, but tend to use rocket-boosted ramjets.

Supersonic cruise missiles do not exist. Supersonic missiles certainly exist, but they're all rockets, from the relatively small and short-range Mach 2.5 Aim-9 Sidewinder to the medium-range AIM-54 Phoenix and the old B-52 http://en.wikipedia.org/wiki/Short-Range_Attack_Missile" to long-range ICBMs.
 
Last edited by a moderator:
  • #21
mugaliens said:
Supersonic cruise missiles do not exist. Supersonic missiles certainly exist, but they're all rockets, from the relatively small and short-range Mach 2.5 Aim-9 Sidewinder to the medium-range AIM-54 Phoenix and the old B-52 http://en.wikipedia.org/wiki/Short-Range_Attack_Missile" to long-range ICBMs.

http://en.wikipedia.org/wiki/Cruise_missile#Categories
 
Last edited by a moderator:
  • #22
mugaliens said:
Supersonic cruise missiles do not exist. Supersonic missiles certainly exist, but they're all rockets, from the relatively small and short-range Mach 2.5 Aim-9 Sidewinder to the medium-range AIM-54 Phoenix and the old B-52 http://en.wikipedia.org/wiki/Short-Range_Attack_Missile" to long-range ICBMs.

That's not true.

OK, I had something typed up, but then realized the missile wasn't listed that wiki website. So, for any confidentiality sake, I'll keep my mouth shut.
 
Last edited by a moderator:
  • #23
russ_watters said:

Poorly written Wikipedia article and more poorly written section.

Let's take the Brahmos as an example. 290 km range at Mach 2.9. That's a 4.9 min time of flight. That's not a "cruise missile," regardless of who chooses to call it that. That's an attack missile, and the velocities, ranges, and time of flight are roughly in the ballpark of the U.S. old SRAMs, which stand for Short-Range Attack Missile. Meanwhile, traditional cruise missiles have ranges measured in the thousands of kilometers, not hundreds.

If they're calling it a "cruise missile" they're doing so for political purposes, as "attack" sounds so war-like...

Realisticially, though, is there any sharp demarcation between a cruise missile and an attack missile? Not really, and all cruise missiles are designed to attack their targets.
 
  • #24
mugaliens said:
If they're calling it a "cruise missile" they're doing so for political purposes, as "attack" sounds so war-like...

Often times "Standoff" is used now, as in JASSM (Joint Air-to-Surface Standoff Missile)
 
  • #25
minger said:
Often times "Standoff" is used now, as in JASSM (Joint Air-to-Surface Standoff Missile)

I find this to be a more accurate term for shorter range, and particularly much faster missiles with shorter time of flight than "cruise."
 
  • #26
mugaliens said:
I find this to be a more accurate term for shorter range, and particularly much faster missiles with shorter time of flight than "cruise."

That isn't really what standoff means. In terms of missiles, standoff is more of a range thing, meaning that the missile can be launched from a range that allows the attacker to evade return fire.
 
  • #27
mugaliens said:
Poorly written Wikipedia article and more poorly written section...

That's not a "cruise missile," regardless of who chooses to call it that. That's an attack missile...
Well it seemed like you were saying supersonic jet powered missiles don't exist - when clearly they do, whether we call them cruise missiles or something else.

And you are implying that the words "supersonic" and "cruise missile" don't even belong in the same sentence, but it's not just the wiki that uses the term. For example, the US DOD has an active program called the "Joint SuperSonic Cruise Missile": http://www.globalsecurity.org/military/systems/munitions/jsscm.htm

And:
Realisticially, though, is there any sharp demarcation between a cruise missile and an attack missile? Not really, and all cruise missiles are designed to attack their targets.
Well right: the SLAM *is* a cruise missile. So basically, you're just arguing against a term that is real but you don't like it. Well, you don't need to like it for it to be real.
 
Last edited:
  • #28
If a supersonic missile isn't a cruise missile but an attack missile, then what do you call a hypersonic missile, mugaliens?
 
  • #29
I have to agree with mugs on this one, the term cruise doesn't lend itself to a missile with such a short flight time.

If it traveled at this speed for a sustained period then yes, but by their definition the F22 attacking a target 100km away could be claimed to be using cruise missiles.

This to me sounds like political correctness for misiles.
 
Last edited:
  • #30
It really has nothing to do with political correctness. It has to do with the mission of the missile. Originally, you had short-range, lightweight missiles fired from planes or the ground that were tasked mainly with shooting down fast-moving targets. However, once they developed technology to put much larger payloads on board and fly them over longer distances and take out slower and larger targets, then the mission of these missiles had changed and they changed to name accordingly. It really doesn't have much to do with the term "cruise" in a traditional aerospace sense. These supersonic cruise missiles fulfill the same mission as a traditional cruise missile, and therefore it isn't ludicrous to continue calling them cruise missiles.
 
  • #31
For the last week I have used my mobile to post on this site (all I've done so far as computing goes), it has fulfilled the same 'mission' as my laptop. I can call it a laptop if I like, but it doesn't make it so. They are two distinct items completing the same tasks.

The PC statement wasn't meant to be taken too seriously, although I do think there is an aspect of it when it comes to naming things such as missiles. To downplay the role so to speak.
 
  • #32
Right, but the real role of ANY weapon is to attack. I don't think that fact is lost on anyone.

jarednjames said:
For the last week I have used my mobile to post on this site (all I've done so far as computing goes), it has fulfilled the same 'mission' as my laptop. I can call it a laptop if I like, but it doesn't make it so. They are two distinct items completing the same tasks.

However, if you wanted, you could call both of them forum posting devices and be completely correct. Still, that isn't the point. The fact that makes computers and cell phones different from missiles in this case is that computers and cell phones each have many different functions. Computers can post on forums but can do a plethora of other things, as I am sure you are aware. Cell phones can also post on forums, but can make calls and do their own collection of tasks. Each of these machines has a very different purpose for being.

With missiles, on the other hand, you have one purpose - to destroy. Whether it is going Mach 0.8 or Mach 2.8, a cruise missile is moving a relatively large payload from point A to point B through the atmosphere to hit a relatively slow or stationary target. The only difference is how fast it is moving. The payload size and delivery method relative to other missiles is what makes it a cruise missile.
 
  • #33
boneh3ad said:
However, if you wanted, you could call both of them forum posting devices and be completely correct.

I'm going to use this point to answer the whole post.

It would be more apt to call both missile types 'attack missiles'. That would be completely correct because, as you have pointed out, that is what all missiles do. However, given that this missile does not 'cruise', it's like me calling my phone a laptop. Although it completes the same job, it does so in a different manner.

There is a difference between supersonic, sustained flight (or supersonic cruise) and going supersonic for a short time. This is why they are now promoting the fact the newest fighter aircraft have supersonic cruise capability and not just 'can go supersonic'.

The fact they have used this terminology, I don't know. But it doesn't make it correct.
 
  • #34
They are using the terminology based on the actual definition of cruise, not the flight definition of cruise.

From Merriam-Webster:
: to move or proceed speedily, smoothly, or effortlessly

The idea behind calling it a cruise missile is because it is flying relatively straight, long distances moving a large payload. You don't see them doing a ton of crazy maneuvers or turns; they usually have fairly easy flight paths and simply "cruise" from point A to point B with their comparatively large payload and accomplish their mission.

It isn't really a misnomer, it is just confusing if you try to think of it in terms of flight regimes. If you think of it in terms of simply what the word cruise means, it makes perfect sense.
 
  • #35
http://dictionary.reference.com/browse/cruise
to fly, drive, or sail at a constant speed that permits maximum operating efficiency for sustained travel.

Now unless the missile is doing none of the above (fly/drive/sail) then the definition applies. (As far as I'm aware, the whole point of a cruise missile is that it's essentially a pilotless aircraft - well bomb)

I have also noted that mirriam webster is the only place I've seen that particular definition (not saying it's wrong). This is just arguing semantics now.

I would however, like to see a reference which shows which definition they are using.
 

Similar threads

  • Aerospace Engineering
2
Replies
43
Views
6K
  • Aerospace Engineering
Replies
14
Views
4K
  • Introductory Physics Homework Help
Replies
3
Views
426
Replies
30
Views
8K
  • Aerospace Engineering
2
Replies
35
Views
3K
  • Aerospace Engineering
Replies
4
Views
3K
  • Sci-Fi Writing and World Building
Replies
30
Views
3K
  • Introductory Physics Homework Help
Replies
1
Views
5K
  • Aerospace Engineering
Replies
5
Views
7K
  • Mechanical Engineering
Replies
4
Views
3K
Back
Top