{"history":[],"article":{"id":"3aced460-7a6f-4b68-9b6f-f4e3d63d2e5a","title":"Rocket candy","slug":"rocket-candy","content":":::summary\n:::\n\n# \n**Rocket candy**, or **R-Candy**, is a type of [rocket propellant](https://bliptext.com/articles/rocket-propellant) for [model rockets](https://bliptext.com/articles/model-rockets) made with a form of [sugar](https://bliptext.com/articles/sugar) as a fuel, and containing an [oxidizer](https://bliptext.com/articles/oxidizer).\nThe propellant can be divided into three groups of components: the fuel, the oxidizer, and the (optional) additive(s).\nIn the past, [sucrose](https://bliptext.com/articles/sucrose) was most commonly used as fuel.\nModern formulations most commonly use [sorbitol](https://bliptext.com/articles/sorbitol) for its ease of production.\nThe most common oxidizer is [potassium nitrate](https://bliptext.com/articles/potassium-nitrate) (KNO3).\n[Potassium nitrate](https://bliptext.com/articles/potassium-nitrate) is most commonly found in [tree stump remover](https://bliptext.com/articles/tree-stump).\nAdditives can be many different substances, and either act as catalysts or enhance the aesthetics of the liftoff or flight.\nA traditional sugar propellant formulation is typically prepared in a 65:35 (13:7) oxidizer to fuel ratio.\nThis ratio can vary from fuel to fuel based on the rate of burn, timing and use.\nThere are many different methods for preparation of a sugar-based rocket propellant.\nDry compression does not require heating; it requires only grinding the components and then packing them into the motor.\nHowever, this method is not recommended for serious experimenting, this is because dry compression is less saturated, and can be dangerous if it falls out the rocket.\nDry heating does not actually melt the KNO3, but it melts the sugar and then the KNO3 grains become suspended in the sugar.\nAlternatively, the method dissolving and heating involves both elements being dissolved in water and then combined by boiling the water off, creating a better mixture.\nThe specific impulse, total impulse, and thrust are generally lower for the same amount of fuel than other composite model rocket fuels, but rocket candy is significantly cheaper.\nIn the United States, rocket candy motors are legal to make, but illegal to transport without a low explosives users permit.\nSince they count as [amateur motors](https://bliptext.com/articles/amateur-rocketry), they are typically launched at sanctioned [Tripoli Rocketry Association](https://bliptext.com/articles/tripoli-rocketry-association) research launches which require users to hold a [Tripoli Rocketry Association](https://bliptext.com/articles/tripoli-rocketry-association) high power [level 2 certification](https://bliptext.com/articles/high-power-rocketry).\nUsers may also launch using these motors by applying for an [FAA](https://bliptext.com/articles/faa) flight waiver.\n\n# Components\nRocket candy can be broken down into three major groups of components: [fuels](https://bliptext.com/articles/fuels), [oxidizers](https://bliptext.com/articles/oxidizers), and additives.\nThe fuel is the substance that burns, releasing rapidly expanding gases that provide thrust as they exit the nozzle.\nThe oxidizer provides oxygen, which is required for the burning process.\nThe additives can be catalysts, to speed up or make the burning more efficient.\nHowever, some additives are more aesthetic, and can add sparks and flames to liftoff, or add smoke for ease of following the rocket in the air.\n\n## Fuels\nMany different sugars are used as the fuel for rocket candy.\nThe most common fuel is typically sucrose, however, [glucose](https://bliptext.com/articles/glucose) and [fructose](https://bliptext.com/articles/fructose) are sometimes used.\nAs an alternative, [sorbitol](https://bliptext.com/articles/sorbitol), a [sugar alcohol](https://bliptext.com/articles/sugar-alcohol) commonly used as a sweetener in food, produces a propellant with a slower burn rate and is less brittle when made into [propellant grains](https://bliptext.com/articles/propellant).\nSugars with a double bonded oxygen, such as fructose and glucose, are less thermally stable and tend to caramelize when overheated.\nSugars that have alcohol groups, like sorbitol, are much less prone to this decomposition.\nSome other commonly used sugars include [erythritol](https://bliptext.com/articles/erythritol), [xylitol](https://bliptext.com/articles/xylitol), [lactitol](https://bliptext.com/articles/lactitol), [maltitol](https://bliptext.com/articles/maltitol), or [mannitol](https://bliptext.com/articles/mannitol).\n\n## Oxidizers\nThe oxidizer most often used in the preparation of sugar motors is [potassium nitrate](https://bliptext.com/articles/potassium-nitrate) (KNO3).\nOther oxidizers can be used as well, such as [sodium](https://bliptext.com/articles/sodium-nitrate) and [calcium](https://bliptext.com/articles/calcium-nitrate) nitrates as well as mixtures of [sodium](https://bliptext.com/articles/sodium-nitrate) and potassium nitrate.\nKNO3 can be acquired through purchasing a granular \"stump remover\" from stores that carry garden supplies.\nOther rarely used oxidizers are ammonium and potassium perchlorate.\nTwo main issues need to be addressed with respect to the oxidizer if one is using potassium nitrate.\nThe most important issue is the purity of the material.\nIf a purchased material does not perform satisfactorily it may be necessary to recrystallize the KNO3.\nThe second important issue with respect to the oxidizer portion of a propellant is its particle size.\nMost propellant makers prefer their KNO3 ground to a small particle size, such as 100 [mesh](https://bliptext.com/articles/mesh-scale) (about 150 μm) or smaller.\nThis can be done using a coffee grinder.\nRock-tumblers can also be used to mill into a fine grained well mixed powder.\n\n## Additives\nAdditives are often added to rocket propellants to modify their burn properties.\nSuch additives may be used to increase or decrease the burn rate of the propellant.\nSome are used to alter the color of the flame or smoke produced.\nThey can also be used to modify a certain physical property of the propellant itself, such as [plasticizers](https://bliptext.com/articles/plasticizers) or [surfactants](https://bliptext.com/articles/surfactant) to facilitate the casting of the formulation.\nThere are many types of experimental additives; the ones listed here are the most commonly used.\nMetal [oxides](https://bliptext.com/articles/oxides) have been found to increase the burn rate of sugar propellants.\nSuch additives have been found to function best at levels from 1 to 5 percent.\nMost often used are iron oxides.\nRed iron oxide is used most often as it is somewhat easier to obtain than the [yellow](https://bliptext.com/articles/iron-iii-oxide-hydroxide), [brown](https://bliptext.com/articles/limonite), or [black](https://bliptext.com/articles/iron-ii-iii-oxide) versions.\nBrown iron oxide exhibits unusual burn rate acceleration properties under pressure.\n[Carbon](https://bliptext.com/articles/carbon) in the form of [charcoal](https://bliptext.com/articles/charcoal), [carbon black](https://bliptext.com/articles/carbon-black), [graphite](https://bliptext.com/articles/graphite), etc; can be and sometimes is used as a fuel in sugar formulations.\nMost often, however, a small amount of carbon is used as an opacifier, making a visible smoke trail.\nThe carbon acts as a heat sink, keeping a portion of the heat of combustion located in the propellant rather than having it transferred quickly to the motor casing.\nIf metallic fuels such as [aluminum](https://bliptext.com/articles/aluminum) or [magnesium](https://bliptext.com/articles/magnesium) are used in a sugar formulation, a danger exists if traces of acids are found in the oxidizer.\nAcidic materials can react readily with the metal, producing [hydrogen](https://bliptext.com/articles/hydrogen) and heat, a dangerous combination.\nThe addition of [weak bases](https://bliptext.com/articles/weak-base) helps to neutralize these acidic materials, greatly reducing their danger.\n[Titanium](https://bliptext.com/articles/titanium) metal in the form of flakes or sponge (about 20 mesh in size) is often added to sugar formulations at levels from 5 to 10% in order to produce a sparking flame and smoke on lift off.\nSurfactants are used to reduce the melting viscosity of sugar propellants.\nFor example, [propylene glycol](https://bliptext.com/articles/propylene-glycol) helps reduce the melt viscosity of sucrose based propellants.\n# [Left is the sample of the basic mixture, right contains 1% of red iron oxide added | upload.wikimedia.org/wikipedia/commons/c/c9/Rocket///candy///samples.jpg]\n\n## Formulations\nA typical sugar propellant formulation is typically prepared in a 13:7 oxidizer to fuel ratio (weight ratio).\nHowever, this formulation is slightly fuel rich, and can be varied by up to 10%.\nThere are other possible formulations that allow for flight in amateur rocketry.\n\n# Preparation\nThere are a number of different methods for preparing a sugar-based rocket propellant.\nThese methods include dry compression, dry heating, and [dissolving](https://bliptext.com/articles/solvation) and heating.\nThe latter two methods involve heating the propellant.\nIn dry compression, the sugar and potassium nitrate are individually ground as finely as possible, and then mixed in a [ball mill](https://bliptext.com/articles/ball-mill) or [tumbler](https://bliptext.com/articles/tumble-finishing) to ensure uniform mixing of the components.\nThis mixture is then compressed into the motor tube, similar to the method for packing black powder into a muzzle loading rifle.\nHowever, this method is rarely used for serious experiments, and careful safety considerations should be made before deciding to employ this method.\nAnother, more common, and safer method of preparing a sugar-based rocket propellant is dry heating.\nFirst, the potassium nitrate is ground or milled to a fine powder, and then thoroughly mixed with powdered sugar which is then heated.\nThis method does not actually melt the potassium nitrate, as the melting temperature of KNO₃ is 323 C, but it melts the sugar and coats the grains of KNO₃ with the melted sugar.\nAn alternative to this method was used by Rick Maschek of the [Sugar Shot to Space](https://bliptext.com/articles/sugar-shot-to-space) project.\nIn which he does not grind or mill the potassium nitrate into a powder which results in a viscosity low enough to make the solution pourable when using sorbitol as the fuel for casting grains.\nThe melting process must be performed using a [heat spreader](https://bliptext.com/articles/heat-spreader), so as to avoid creating autoignition hot-spots.\nJames Yawn advocates for the dissolving and heating method.\nDissolving and heating the propellant actually dissolves both elements of the propellant and combines them.\nFirst, the KNO₃ and sugar are placed in a pot or saucepan.\nThen, just enough water is added to be able to completely dissolve the KNO₃ and the sugar.\nThe mixture is then heated and brought to a boil until the water evaporates.\nThe mixture goes through several stages: first boiling, then bubbling and spitting, then its consistency becomes smooth and creamy.\nThere are several advantages to dissolving the sugar and KNO₃ in water before heating.\nOne advantage is that the KNO₃ and the sugar do not have to be finely powdered, because they both end up completely dissolved.\nIt can be also be prepared at a lower temperature and requires less stirring.\nThis method of preparation also causes the resultant propellant to resist caramelization in the pot, giving more time to pack it into the motors.\nA possible negative is that the resultant propellant is a little thicker (more viscous).\nThe mixture is not pourable and requires scooping into a mold, and won’t ever be as thin as the dry heating method.\n\n# Performance\nSugar based rocket propellants have an average Isp([specific impulse](https://bliptext.com/articles/specific-impulse)) of between 114 and 130 seconds.\nCompare that to the average Isp of an [APCP](https://bliptext.com/articles/ammonium-perchlorate-composite-propellant) ([Ammonium perchlorate](https://bliptext.com/articles/ammonium-perchlorate) composite propellant), which is 180 to 260 seconds.\n[Sorbitol](https://bliptext.com/articles/sorbitol) and KNO3 based propellants with a typical 35:65 ratio are capable of an Isp of between 110 and 125 seconds.\nHowever, sorbitol and KNO3 rockets with additives have been recorded as having specific impulses of up to 128 seconds.\n[Xylitol](https://bliptext.com/articles/xylitol) and KNO3 based rocket propellants are capable of a specific impulse of ~100 seconds.\nThese have an unconfined burn rate of about 1.3 mm/s.\n[Dextrose](https://bliptext.com/articles/glucose) and KNO3 based fuels are capable of an Isp of 137 seconds.\nOverall, the performance characteristics of sugar rockets approach those of professional grade propellants.\n\n# Applications\nRocket candy is also occasionally known as \"caramel candy\", a term that was popularized by [Bertrand R. Brinley](https://bliptext.com/articles/bertrand-r-brinley), in his book on [amateur rocketry](https://bliptext.com/articles/amateur-rocketry), Rocket Manual for Amateurs, published in 1960.\nThis propellant was used in some of the amateur rockets described by [Homer Hickam](https://bliptext.com/articles/homer-hickam) in his best-selling [memoir](https://bliptext.com/articles/memoir) [Rocket Boys](https://bliptext.com/articles/rocket-boys).\nRocket candy was also employed in a small amateur rocket described by Lt. Col. Charles M. Parkin in a lengthy [Electronics Illustrated](https://bliptext.com/articles/electronics-illustrated) article that continued over several issues, beginning in July 1958.\nParkin described how to prepare the propellant mixture by using an electric frying pan as a heat source for the melting operation.\nThis article was reprinted in Parkin's book, The Rocket Handbook for Amateurs, which was published in 1959.\nParkin's article contributed to the increasing popularity of the rocket candy propellant among amateur rocket groups beginning in the late 1950s and early 1960s.\nSugar-fueled rockets have been used as crude weapons of war, such as during [the attacks on Israel](https://bliptext.com/articles/qassam-rocket) by [Hamas](https://bliptext.com/articles/hamas) during 2000-2003.\nThe [Sugar Shot to Space](https://bliptext.com/articles/sugar-shot-to-space) program (SS2S) was formed with the goal \"to loft a rocket powered by a 'sugar propellant' into space\" equivalent to 100 km in altitude.\nThe Double Sugar Shot rocket was expected to reach 33 km, or one third of the goal altitude.\nThe first Mini Sugar Shot rocket, a single-stage dual-pulse design motor prototype of the Extreme Sugar Shot rocket, reached an altitude of 4 km before a catastrophic motor malfunction occurred; contact with the second Mini Sugar Shot rocket was lost at an altitude of nearly 6 km going in excess of Mach 1.\nIn 2017 Rick Maschek and Chris Covany of the SS2S team successfully launched their 150mm potassium nitrate sorbitol propellant rocket at over Mach 2.5 and was followed later that same year by Rick and Eric Beckner of the SS2S team with the first of two successful 300mm KNSB motor static motor tests, largest 'sugar' motors ever, at the Friends of Amateur Rocketry (FAR) facility showing large 'sugar' motors could be made.\nThe Extreme Sugar Shot rocket, now planned as a conventional 2-stage rocket design and the rocket expected to meet the goal of entering space, has not yet been completed.\n# [BATES grain of a simple sorbitol mixture | upload.wikimedia.org/wikipedia/commons/8/85/Rocket///candy///BATES///grain.JPG]","current_revision":null,"created_by":"kACnuQmH5k9Nr5VNVEpVeg7XpvUmMctD","created_at":"2025-01-25T22:38:18.128Z","updated_at":"2025-01-25T22:38:18.128Z","search_vector":"'candi':2 'rocket':1","search_content":" \n \n\n# \n**Rocket candy**, or **R-Candy**, is a type of [rocket propellant](https://bliptext.com/articles/rocket-propellant) for [model rockets](https://bliptext.com/articles/model-rockets) made with a form of [sugar](https://bliptext.com/articles/sugar) as a fuel, and containing an [oxidizer](https://bliptext.com/articles/oxidizer).\nThe propellant can be divided into three groups of components: the fuel, the oxidizer, and the (optional) additive(s).\nIn the past, [sucrose](https://bliptext.com/articles/sucrose) was most commonly used as fuel.\nModern formulations most commonly use [sorbitol](https://bliptext.com/articles/sorbitol) for its ease of production.\nThe most common oxidizer is [potassium nitrate](https://bliptext.com/articles/potassium-nitrate) (KNO3).\n[Potassium nitrate](https://bliptext.com/articles/potassium-nitrate) is most commonly found in [tree stump remover](https://bliptext.com/articles/tree-stump).\nAdditives can be many different substances, and either act as catalysts or enhance the aesthetics of the liftoff or flight.\nA traditional sugar propellant formulation is typically prepared in a 65:35 (13:7) oxidizer to fuel ratio.\nThis ratio can vary from fuel to fuel based on the rate of burn, timing and use.\nThere are many different methods for preparation of a sugar-based rocket propellant.\nDry compression does not require heating; it requires only grinding the components and then packing them into the motor.\nHowever, this method is not recommended for serious experimenting, this is because dry compression is less saturated, and can be dangerous if it falls out the rocket.\nDry heating does not actually melt the KNO3, but it melts the sugar and then the KNO3 grains become suspended in the sugar.\nAlternatively, the method dissolving and heating involves both elements being dissolved in water and then combined by boiling the water off, creating a better mixture.\nThe specific impulse, total impulse, and thrust are generally lower for the same amount of fuel than other composite model rocket fuels, but rocket candy is significantly cheaper.\nIn the United States, rocket candy motors are legal to make, but illegal to transport without a low explosives users permit.\nSince they count as [amateur motors](https://bliptext.com/articles/amateur-rocketry), they are typically launched at sanctioned [Tripoli Rocketry Association](https://bliptext.com/articles/tripoli-rocketry-association) research launches which require users to hold a [Tripoli Rocketry Association](https://bliptext.com/articles/tripoli-rocketry-association) high power [level 2 certification](https://bliptext.com/articles/high-power-rocketry).\nUsers may also launch using these motors by applying for an [FAA](https://bliptext.com/articles/faa) flight waiver.\n\n# Components\nRocket candy can be broken down into three major groups of components: [fuels](https://bliptext.com/articles/fuels), [oxidizers](https://bliptext.com/articles/oxidizers), and additives.\nThe fuel is the substance that burns, releasing rapidly expanding gases that provide thrust as they exit the nozzle.\nThe oxidizer provides oxygen, which is required for the burning process.\nThe additives can be catalysts, to speed up or make the burning more efficient.\nHowever, some additives are more aesthetic, and can add sparks and flames to liftoff, or add smoke for ease of following the rocket in the air.\n\n## Fuels\nMany different sugars are used as the fuel for rocket candy.\nThe most common fuel is typically sucrose, however, [glucose](https://bliptext.com/articles/glucose) and [fructose](https://bliptext.com/articles/fructose) are sometimes used.\nAs an alternative, [sorbitol](https://bliptext.com/articles/sorbitol), a [sugar alcohol](https://bliptext.com/articles/sugar-alcohol) commonly used as a sweetener in food, produces a propellant with a slower burn rate and is less brittle when made into [propellant grains](https://bliptext.com/articles/propellant).\nSugars with a double bonded oxygen, such as fructose and glucose, are less thermally stable and tend to caramelize when overheated.\nSugars that have alcohol groups, like sorbitol, are much less prone to this decomposition.\nSome other commonly used sugars include [erythritol](https://bliptext.com/articles/erythritol), [xylitol](https://bliptext.com/articles/xylitol), [lactitol](https://bliptext.com/articles/lactitol), [maltitol](https://bliptext.com/articles/maltitol), or [mannitol](https://bliptext.com/articles/mannitol).\n\n## Oxidizers\nThe oxidizer most often used in the preparation of sugar motors is [potassium nitrate](https://bliptext.com/articles/potassium-nitrate) (KNO3).\nOther oxidizers can be used as well, such as [sodium](https://bliptext.com/articles/sodium-nitrate) and [calcium](https://bliptext.com/articles/calcium-nitrate) nitrates as well as mixtures of [sodium](https://bliptext.com/articles/sodium-nitrate) and potassium nitrate.\nKNO3 can be acquired through purchasing a granular \"stump remover\" from stores that carry garden supplies.\nOther rarely used oxidizers are ammonium and potassium perchlorate.\nTwo main issues need to be addressed with respect to the oxidizer if one is using potassium nitrate.\nThe most important issue is the purity of the material.\nIf a purchased material does not perform satisfactorily it may be necessary to recrystallize the KNO3.\nThe second important issue with respect to the oxidizer portion of a propellant is its particle size.\nMost propellant makers prefer their KNO3 ground to a small particle size, such as 100 [mesh](https://bliptext.com/articles/mesh-scale) (about 150 μm) or smaller.\nThis can be done using a coffee grinder.\nRock-tumblers can also be used to mill into a fine grained well mixed powder.\n\n## Additives\nAdditives are often added to rocket propellants to modify their burn properties.\nSuch additives may be used to increase or decrease the burn rate of the propellant.\nSome are used to alter the color of the flame or smoke produced.\nThey can also be used to modify a certain physical property of the propellant itself, such as [plasticizers](https://bliptext.com/articles/plasticizers) or [surfactants](https://bliptext.com/articles/surfactant) to facilitate the casting of the formulation.\nThere are many types of experimental additives; the ones listed here are the most commonly used.\nMetal [oxides](https://bliptext.com/articles/oxides) have been found to increase the burn rate of sugar propellants.\nSuch additives have been found to function best at levels from 1 to 5 percent.\nMost often used are iron oxides.\nRed iron oxide is used most often as it is somewhat easier to obtain than the [yellow](https://bliptext.com/articles/iron-iii-oxide-hydroxide), [brown](https://bliptext.com/articles/limonite), or [black](https://bliptext.com/articles/iron-ii-iii-oxide) versions.\nBrown iron oxide exhibits unusual burn rate acceleration properties under pressure.\n[Carbon](https://bliptext.com/articles/carbon) in the form of [charcoal](https://bliptext.com/articles/charcoal), [carbon black](https://bliptext.com/articles/carbon-black), [graphite](https://bliptext.com/articles/graphite), etc; can be and sometimes is used as a fuel in sugar formulations.\nMost often, however, a small amount of carbon is used as an opacifier, making a visible smoke trail.\nThe carbon acts as a heat sink, keeping a portion of the heat of combustion located in the propellant rather than having it transferred quickly to the motor casing.\nIf metallic fuels such as [aluminum](https://bliptext.com/articles/aluminum) or [magnesium](https://bliptext.com/articles/magnesium) are used in a sugar formulation, a danger exists if traces of acids are found in the oxidizer.\nAcidic materials can react readily with the metal, producing [hydrogen](https://bliptext.com/articles/hydrogen) and heat, a dangerous combination.\nThe addition of [weak bases](https://bliptext.com/articles/weak-base) helps to neutralize these acidic materials, greatly reducing their danger.\n[Titanium](https://bliptext.com/articles/titanium) metal in the form of flakes or sponge (about 20 mesh in size) is often added to sugar formulations at levels from 5 to 10% in order to produce a sparking flame and smoke on lift off.\nSurfactants are used to reduce the melting viscosity of sugar propellants.\nFor example, [propylene glycol](https://bliptext.com/articles/propylene-glycol) helps reduce the melt viscosity of sucrose based propellants.\n# [Left is the sample of the basic mixture, right contains 1% of red iron oxide added | upload.wikimedia.org/wikipedia/commons/c/c9/Rocket///candy///samples.jpg]\n\n## Formulations\nA typical sugar propellant formulation is typically prepared in a 13:7 oxidizer to fuel ratio (weight ratio).\nHowever, this formulation is slightly fuel rich, and can be varied by up to 10%.\nThere are other possible formulations that allow for flight in amateur rocketry.\n\n# Preparation\nThere are a number of different methods for preparing a sugar-based rocket propellant.\nThese methods include dry compression, dry heating, and [dissolving](https://bliptext.com/articles/solvation) and heating.\nThe latter two methods involve heating the propellant.\nIn dry compression, the sugar and potassium nitrate are individually ground as finely as possible, and then mixed in a [ball mill](https://bliptext.com/articles/ball-mill) or [tumbler](https://bliptext.com/articles/tumble-finishing) to ensure uniform mixing of the components.\nThis mixture is then compressed into the motor tube, similar to the method for packing black powder into a muzzle loading rifle.\nHowever, this method is rarely used for serious experiments, and careful safety considerations should be made before deciding to employ this method.\nAnother, more common, and safer method of preparing a sugar-based rocket propellant is dry heating.\nFirst, the potassium nitrate is ground or milled to a fine powder, and then thoroughly mixed with powdered sugar which is then heated.\nThis method does not actually melt the potassium nitrate, as the melting temperature of KNO 3 is 323 C, but it melts the sugar and coats the grains of KNO 3 with the melted sugar.\nAn alternative to this method was used by Rick Maschek of the [Sugar Shot to Space](https://bliptext.com/articles/sugar-shot-to-space) project.\nIn which he does not grind or mill the potassium nitrate into a powder which results in a viscosity low enough to make the solution pourable when using sorbitol as the fuel for casting grains.\nThe melting process must be performed using a [heat spreader](https://bliptext.com/articles/heat-spreader), so as to avoid creating autoignition hot-spots.\nJames Yawn advocates for the dissolving and heating method.\nDissolving and heating the propellant actually dissolves both elements of the propellant and combines them.\nFirst, the KNO 3 and sugar are placed in a pot or saucepan.\nThen, just enough water is added to be able to completely dissolve the KNO 3 and the sugar.\nThe mixture is then heated and brought to a boil until the water evaporates.\nThe mixture goes through several stages: first boiling, then bubbling and spitting, then its consistency becomes smooth and creamy.\nThere are several advantages to dissolving the sugar and KNO 3 in water before heating.\nOne advantage is that the KNO 3 and the sugar do not have to be finely powdered, because they both end up completely dissolved.\nIt can be also be prepared at a lower temperature and requires less stirring.\nThis method of preparation also causes the resultant propellant to resist caramelization in the pot, giving more time to pack it into the motors.\nA possible negative is that the resultant propellant is a little thicker (more viscous).\nThe mixture is not pourable and requires scooping into a mold, and won’t ever be as thin as the dry heating method.\n\n# Performance\nSugar based rocket propellants have an average Isp([specific impulse](https://bliptext.com/articles/specific-impulse)) of between 114 and 130 seconds.\nCompare that to the average Isp of an [APCP](https://bliptext.com/articles/ammonium-perchlorate-composite-propellant) ([Ammonium perchlorate](https://bliptext.com/articles/ammonium-perchlorate) composite propellant), which is 180 to 260 seconds.\n[Sorbitol](https://bliptext.com/articles/sorbitol) and KNO3 based propellants with a typical 35:65 ratio are capable of an Isp of between 110 and 125 seconds.\nHowever, sorbitol and KNO3 rockets with additives have been recorded as having specific impulses of up to 128 seconds.\n[Xylitol](https://bliptext.com/articles/xylitol) and KNO3 based rocket propellants are capable of a specific impulse of ~100 seconds.\nThese have an unconfined burn rate of about 1.3 mm/s.\n[Dextrose](https://bliptext.com/articles/glucose) and KNO3 based fuels are capable of an Isp of 137 seconds.\nOverall, the performance characteristics of sugar rockets approach those of professional grade propellants.\n\n# Applications\nRocket candy is also occasionally known as \"caramel candy\", a term that was popularized by [Bertrand R. Brinley](https://bliptext.com/articles/bertrand-r-brinley), in his book on [amateur rocketry](https://bliptext.com/articles/amateur-rocketry), Rocket Manual for Amateurs, published in 1960.\nThis propellant was used in some of the amateur rockets described by [Homer Hickam](https://bliptext.com/articles/homer-hickam) in his best-selling [memoir](https://bliptext.com/articles/memoir) [Rocket Boys](https://bliptext.com/articles/rocket-boys).\nRocket candy was also employed in a small amateur rocket described by Lt. Col. Charles M. Parkin in a lengthy [Electronics Illustrated](https://bliptext.com/articles/electronics-illustrated) article that continued over several issues, beginning in July 1958.\nParkin described how to prepare the propellant mixture by using an electric frying pan as a heat source for the melting operation.\nThis article was reprinted in Parkin's book, The Rocket Handbook for Amateurs, which was published in 1959.\nParkin's article contributed to the increasing popularity of the rocket candy propellant among amateur rocket groups beginning in the late 1950s and early 1960s.\nSugar-fueled rockets have been used as crude weapons of war, such as during [the attacks on Israel](https://bliptext.com/articles/qassam-rocket) by [Hamas](https://bliptext.com/articles/hamas) during 2000-2003.\nThe [Sugar Shot to Space](https://bliptext.com/articles/sugar-shot-to-space) program (SS2S) was formed with the goal \"to loft a rocket powered by a 'sugar propellant' into space\" equivalent to 100 km in altitude.\nThe Double Sugar Shot rocket was expected to reach 33 km, or one third of the goal altitude.\nThe first Mini Sugar Shot rocket, a single-stage dual-pulse design motor prototype of the Extreme Sugar Shot rocket, reached an altitude of 4 km before a catastrophic motor malfunction occurred; contact with the second Mini Sugar Shot rocket was lost at an altitude of nearly 6 km going in excess of Mach 1.\nIn 2017 Rick Maschek and Chris Covany of the SS2S team successfully launched their 150mm potassium nitrate sorbitol propellant rocket at over Mach 2.5 and was followed later that same year by Rick and Eric Beckner of the SS2S team with the first of two successful 300mm KNSB motor static motor tests, largest 'sugar' motors ever, at the Friends of Amateur Rocketry (FAR) facility showing large 'sugar' motors could be made.\nThe Extreme Sugar Shot rocket, now planned as a conventional 2-stage rocket design and the rocket expected to meet the goal of entering space, has not yet been completed.\n# [BATES grain of a simple sorbitol mixture | upload.wikimedia.org/wikipedia/commons/8/85/Rocket///candy///BATES///grain.JPG]","revisionCount":0},"hasMore":false,"nextCursor":null}

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