# Difference between rockets and missiles?
**URL:** https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117
**Category:** Factual Questions
**Created:** [July 26, 2014, 8:21pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117 "2014-07-26T20:21:36Z")
**Posts on this page:** 20
**Page:** 2
### Author:  [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)
#### Post date: [July 28, 2014, 2:36am UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/21 "2014-07-28T02:36:53Z")
> [@Terr](#):
>
> Not target. Purpose.
назначения (naznacheniya) can be translated as purpose or as target. Or as destination or assignment or application or function or designation, depending on the context.
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### Author:  [@Terr](https://boards.straightdope.com/u/Terr)
#### Post date: [July 28, 2014, 4:15am UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/22 "2014-07-28T04:15:56Z")
> [@Little\_Nemo](#):
>
> назначения (naznacheniya) can be translated as purpose or as target. Or as destination or assignment or application or function or designation, depending on the context.
🙂 Well in this case it is purpose or designation. Translating “naznachenie” as “target” is a big stretch. There is already a perfectly good word for “target” in Russian.
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### Author:  [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)
#### Post date: [July 28, 2014, 7:09am UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/23 "2014-07-28T07:09:55Z")
The only accurate word is назначения. Everything else, including all English translations, are approximations.
I agree that the more usual translation for target would be цель or мишень. And devoid of all context, the most usual translation for назначения would be destination.
But, as I said, all translations are approximations. I figured the best approximation for назначения when you’re talking in the context of “destination that you’re aiming a nuclear missile at” is “target”.
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### Author:  [@Terr](https://boards.straightdope.com/u/Terr)
#### Post date: [July 28, 2014, 7:21am UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/24 "2014-07-28T07:21:04Z")
> [@Little\_Nemo](#):
>
> But, as I said, all translations are approximations. I figured the best approximation for назначения when you’re talking in the context of “destination that you’re aiming a nuclear missile at” is “target”.
Except that’s not the context. The context is strategic purposes of the rockets. The targets are incidental to that.
Look, I lived in Russia for 16 years, at the time that the “RVSN” existed. Russian is my native tongue. I think I know what the phrase means.
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### Author:  [@Bozuit](https://boards.straightdope.com/u/Bozuit)
#### Post date: [July 29, 2014, 12:42pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/25 "2014-07-29T12:42:48Z")
> [@bump](#):
>
> For example, a RPG is a rocket-propelled grenade, but acts essentially like a rocket.
Slight hijack question: I don’t see how an RPG is a “rocket-propelled grenade [that] acts … like a rocket”. In what sense is it a grenade (it seems like one would have to stretch the definition) and in what sense is it _not_ a rocket? I mean, I know “grenade” is there in the name (even in the original Russian), but a grenade is supposed to be a handheld bomb. A “normal” grenade launcher at least approximates a really good throw, but in the case of an RPG, can the definition really be extended that far?
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### Author:  [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)
#### Post date: [July 29, 2014, 1:20pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/26 "2014-07-29T13:20:31Z")
> [@Bozuit](#):
>
> Slight hijack question: I don’t see how an RPG is a “rocket-propelled grenade [that] acts … like a rocket”. In what sense is it a grenade (it seems like one would have to stretch the definition) and in what sense is it _not_ a rocket? I mean, I know “grenade” is there in the name (even in the original Russian), but a grenade is supposed to be a handheld bomb. A “normal” grenade launcher at least approximates a really good throw, but in the case of an RPG, can the definition really be extended that far?
Mr. Webster says a grenade is " a small missile…thrown or launched by another method, such as a rifle or small rocket."
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### Author:  [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)
#### Post date: [July 29, 2014, 1:29pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/27 "2014-07-29T13:29:53Z")
> [@bump](#):
>
> In modern usage, it’s pretty simple. Rockets are unguided, while missiles are guided.
>
> Ballistic missiles are guided, but for all intents and purposes follow a ballistic trajectory and the guidance is intended to tweak the ballistic trajectory so that the missile hits the target. There’s no actual maneuvering like there is with say… a AIM-9 Sidewinder.
>
> Rockets are pretty much ballistic by nature, while missiles aren’t necessarily.
None of this is strictly correct, and in overall in this thread there seems to be a general tendency to define the terms in some vague, colloquially fashion rather than to use the existing and consistent definitions.
Generically speaking, a rocket is a propulsion system (sometimes applied to the entire vehicle, other times just the booster system and its onboard guidance and navigation systems) which is powered by purely internal heating (typically chemical combustion of onboard exothermic propellants, although externally heated rockets are possible as well) which ejects material through one or more nozzles which accelerate the flow and allow it to expand to gain maximum thermodynamic efficiency. This is distinguished from ducted (air-breathing) propulsion systems which take the working fluid from the surrounding environment and typically use it as the oxidizer as well, thus reducing carried propellants and substantially increasing specific impulse.
What we colloquially term rockets are composed of (generally) cylindrical stages which are either stacked one on top of the other or in parallel which ascend in an initial upward direction with minimal contribution of aerodynamic lift although there are a handful of exceptions such as the air-launched Orbital Pegasus vehicle which “launches” horizontally and has a small delta wing that provides some modest amount of lift early in flight. Rockets, and in particular those used for medium-to-long range ballistic missiles and for orbital launch (which are similar to and often based upon or derived from MRBMs and ICBMs) definitely maneuver and in fact have inertial guidance systems which are much more complex and precise than any short range missile such as the Sidewinder. Rockets which do not have onboard guidance and thrust control vectoring (TVC) systems require some kind of aerodynamic (fins) or gyroscopic (spinning) stabilization which is often undesirable in terms of performance and accuracy.
In generic terms, a missile is a projectile which may be guided or unguided, powered or unpowered, and equipped with any type of weapon or warhead or none at all but intended to be or deliver a weapon to destroy a target. Some missiles are rocket powered or at least initially launched by a first stage rocket motor, and then fly via ducted propulsion such as the BGM-109 ‘Tomahawk’ cruise missile. Others are purely rocket propelled delivery systems such as the Ikara anti-submarine missile, the AIM-120 AMRAAM air-to-air missile, or the FIM-92 ‘Stinger’. Some are unpowered like the “Brilliant Pebbles” interceptor. Ballistic missiles are a known by that name not because the missile itself flies on a ballistic path–it does not–but rather it puts the payload (reentry vehicle or RV) on an arcing, ellipsoidal trajectory which is governed purely by external ballistic forces, e.g. gravity and aerodynamic interactions, although some modern RVs known as MaRVs have control surfaces and adjustable mass properties to effect considerable maneuverability.
One point of note on nomenclature that people working outside the propulsion field often get confused about (aided by errors propagated by hobbyists); on vehicles using solid propellents, the propulsive element is called a _ **motor** _, while with liquid and hybrid powered systems they are _ **engines** _. Of course, many space launch vehicles use a combination, with strap-on solid motors making the “zero stage(s)” and main propulsive stages having liquid engines, and then kick/apogee/insertion upper stages which may be propelled by solid motors (Orbus-21, Star-48) or liquid engines (Centaur, HAPS).
Stranger
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### Author:  [@Bozuit](https://boards.straightdope.com/u/Bozuit)
#### Post date: [July 29, 2014, 1:35pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/28 "2014-07-29T13:35:54Z")
> [@carnivorousplant](#):
>
> Mr. Webster says a grenade is " a small missile…thrown or launched by another method, such as a rifle or small rocket."
I can’t find the word “rocket” on [this page](http://www.merriam-webster.com/dictionary/grenade).
Would anyone have said that’s what a grenade means before someone came up with the idea of referring to RPGs as “grenades”? Perhaps they were only referred to as grenades by analogy.
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### Author:  [@Diceman](https://boards.straightdope.com/u/Diceman)
#### Post date: [July 29, 2014, 1:49pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/29 "2014-07-29T13:49:59Z")
In common usage, any non-military application is a rocket. Those things that put satellites into space are most certainly guided to a specific point, but they’re not called “missles.” Military ordinance is a missle if it’s a guided weapon, and a rocket if it’s unguided.
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### Author:  [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)
#### Post date: [July 29, 2014, 2:59pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/30 "2014-07-29T14:59:13Z")
> [@Bozuit](#):
>
> I can’t find the word “rocket” on [this page](http://www.merriam-webster.com/dictionary/grenade).
>
> Would anyone have said that’s what a grenade means before someone came up with the idea of referring to RPGs as “grenades”? Perhaps they were only referred to as grenades by analogy.
Sorry, the Ninth Collegiate does indeed say “or by another method.”
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [July 29, 2014, 4:49pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/31 "2014-07-29T16:49:18Z")
“Webster” is not a particular dictionary company. Many different dictionaries, from different publishers and used for different purposes, use the Webster name.
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### Author:  [@Keeve](https://boards.straightdope.com/u/Keeve)
#### Post date: [July 29, 2014, 5:28pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/32 "2014-07-29T17:28:03Z")
> [@Exapno\_Mapcase](#):
>
> The word rocket zooms up [starting in WWII](https://books.google.com/ngrams/graph?content=rocket%2Cmissile&year_start=1800&year_end=2000&corpus=15&smoothing=3&share=&direct_url=t1%3B%2Crocket%3B%2Cc0%3B.t1%3B%2Cmissile%3B%2Cc0) and missile lags by about a decade, not getting common until the concept of intercontinental war via missile became a hot topic. Willy Ley’s classic book on the subject appeared as \*Rockets \*in 1944, as _Rockets and Space Travel_ in 1947, and finally as _Rockets, Missiles, and Space Travel_ in 1951, and I consider him a leading indicator.
I won’t argue about the increase in usage. I just want to point out that the word “rocket” was indeed in use long before that.
> [@Francis Scott Key](#):
>
> … and the Rockets’ red glare, the Bombs bursting in air …
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### Author:  [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)
#### Post date: [July 29, 2014, 5:50pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/33 "2014-07-29T17:50:38Z")
> [@Keeve](#):
>
> I won’t argue about the increase in usage. I just want to point out that the word “rocket” was indeed in use long before that.
Really? What deep knowledge. Thanks for sharing it with us.
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### Author:  [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)
#### Post date: [July 29, 2014, 7:19pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/34 "2014-07-29T19:19:50Z")
> [@Chronos](#):
>
> “Webster” is not a particular dictionary company. Many different dictionaries, from different publishers and used for different purposes, use the Webster name.
Merriam-Webster 9th New Collegiate, 1987.
They have a disclaimer to that fact in the book. 🙂
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### Author:  [@gnoitall](https://boards.straightdope.com/u/gnoitall)
#### Post date: [July 29, 2014, 7:28pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/35 "2014-07-29T19:28:06Z")
> [@Keeve](#):
>
> I won’t argue about the increase in usage. I just want to point out that the word “rocket” was indeed in use long before that.
Right. The rockets glaring red while bursting were the famous Congreve rockets.
In fact, “rocket artillery” was a commonly-used phrase for unguided rocket-propelled ballistic combat missiles, even in modern examples as the M270 Multiple Launch Rocket System.
In modern US military usage, the absence of precision terminal guidance makes it a rocket, rather than a missile. As far as I know, though, the name doesn’t change if someone mates an M270A with an MGM-140B or MGM-168 ATacMS\* canister, which uses GPS-guided missiles.
\*Army Tactical Missile System… a missile launched from a rocket launcher. Go figure.
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### Author:  [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)
#### Post date: [July 29, 2014, 8:21pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/36 "2014-07-29T20:21:46Z")
> [@gnoitall](#):
>
> Right. The rockets glaring red while bursting were the famous Congreve rockets.
I have read that they were very inaccurate, and used often to fire along the ground and frighten cavalry horses.
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### Author:  [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)
#### Post date: [July 29, 2014, 9:17pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/37 "2014-07-29T21:17:48Z")
> [@Stranger\_On\_A\_Train](#):
>
> One point of note on nomenclature that **people working outside the propulsion field** often get confused about (aided by errors propagated by hobbyists); on vehicles using solid propellents, the propulsive element is called a _ **motor** _
Or, say, [NASA](http://www.grc.nasa.gov/WWW/k-12/rocket/rktengine.html)?
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### Author:  [@cmdrpiffle](https://boards.straightdope.com/u/cmdrpiffle)
#### Post date: [July 29, 2014, 9:55pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/38 "2014-07-29T21:55:50Z")
Back to the OP’s question:
Generally in the terms that are commonly used… A rocket is unguided, a missile is guided
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### Author:  [@wolfpup](https://boards.straightdope.com/u/wolfpup)
#### Post date: [July 29, 2014, 10:00pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/39 "2014-07-29T22:00:18Z")
> [@Dr.Strangelove](#):
>
> Or, say, [NASA](http://www.grc.nasa.gov/WWW/k-12/rocket/rktengine.html)?
Ahh, the subtle differentiations in the meanings of words! That NASA page is talking about something subtly different than what **Stranger** was talking about. It’s not referring to the combustion chamber and nozzle at the end of a solid rocket (a “motor” in the sense that it produces thrust and hence motion) but rather to the complete system of solid fuel + motor assembly than can be purchased as a unit and installed in the shell of a rocket.
The distinction between “motor” and “engine” seems to be that a motor is anything that produces motion while engine is a more general term for machinery that creates mechanical power from latent energy. So “engine” seems appropriate for that entire cartridge-like assembly that you can buy to power amateur solid-fuel rockets.
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### Author:  [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)
#### Post date: [July 29, 2014, 10:19pm UTC](https://boards.straightdope.com/t/difference-between-rockets-and-missiles/694117/40 "2014-07-29T22:19:51Z")
> [@wolfpup](#):
>
> The distinction between “motor” and “engine” seems to be that a motor is anything that produces motion while engine is a more general term for machinery that creates mechanical power from latent energy. So “engine” seems appropriate for that entire cartridge-like assembly that you can buy to power amateur solid-fuel rockets.
I’m not so sure about that. The Estes site seems to use “motor” and “engine” interchangeably for their complete solid-fuel assemblies. And “motor”, when used to refer to boosters for launch vehicles, definitely refers to the entire assembly and not just the nozzle. Furthermore, I don’t think you can really separate out the “motor” part on a solid-fuel rocket, as there’s no combustion chamber as such; the entire length of the assembly acts as the chamber (which grows as the fuel is consumed).
The motor vs. engine debate is wider than just rockets and just as fruitless IMHO. Engine _tends_ to be applied to propulsion devices that are more machinery-like, but there are just too many exceptions, even among terms used by experts.
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