"It isn't exactly Rocket Science" The artsy science of rocket propulsion

Distributed Nonlinear MPC Formation Control with Limited Bandwidth

It isn't exactly Rocket Science

The artsy science of rocket propulsion

Bilal A. Siddiqui October 07, 2016Invited Lecture Session

IntroductionPublishing and ProducingScience is necessarily innovative. It cannot stagnate.Research in many Pakistani universities has stagnated to Publishing.Its publish of perish, for individuals.But publishing for the sake of publishing is perishing the society.We need to selfish collectively, not individually.Zalimaa Science Pila day!

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Distributed NMPC Formation Control with Limited Bandwidth3

Science SellsWe are consumers of technology, not producers.We spend money ON technology, not FROM it.Universities have huge resources which can make commercializable products.But Pakistani universities are more interested in teaching standard curricula with little out of the box thinking.To change this, we need to change the way we think.Education needs to be student centered, soft wired.

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www.hearlihy.com Briefly about propulsionIt is a simple reaction engine, much like any other aviation engine.A mass of fluid is accelerated somehowThis propelled mass exerts an equal and opposite force on the engine6

Jet Propulsion ClassificationsAir-Breathing SystemsAlso called duct propulsion.Vehicle carries own fuel; surrounding air (an oxidizer) is used for combustion and thrust generationGas turbine engines on aircraft

Rocket PropulsionVehicle carries own fuel and oxidizer, or other expelled propellant to generate thrust:Can operate outside of the Earths atmosphereLaunch vehicles, upper stages, Earth orbiting satellites and interplanetary spacecraft or

www.gadgets-reviews.com or go karts!

www.the-rocketman.com a rocket powered scooter!

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Early HistoryChina, 1232Chinese history in the use of primitive rockets spans centuriesArmies fired flaming rockets at enemiesBattle of Kai-fung-fu, rockets launched could be heard for 15 miles when launched and upon impact devastated everything in all directions for 2,000 feetCarried incendiary materials and iron shrapnelEssntially bamboo filled with gunpowderArmies started preferring cannons to Chinese rockets

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Early History Tipu SultanNext breakthrough came in IndiaMysorean rockets were the first iron-cased rockets successfully deployed for military use. Hyder Ali and son Tipu Sultan used them against the British during the 1780s. This exposed the British to this technology, which was then used to advance European rocketry with the development of the Congreve rocket in 1804.Rocket became in vogue again!


History British and the US

British developed a rocket program. Used this program on United StatesBombed Baltimore for 25 hoursFrancis Scott Key wrote poem ...and the rockets red glare...gave proof through the night that our flag was still there...Confederate States of America, 186412 foot long rocket, 10 pounds of gunpowderLaunched from Richmond, VirginiaIntended to be first ballistic missileTarget was Washington, D.C.Brass case marked C.S.A.Roar out of sightNever found


So what was the point?Rockets = weapons

No real thought on how they worked or functioned

No control, just light it and hope it doesnt return

Someone changed all that

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Jules Verne 1866, published, From the Earth to the Moon

He changed the thinking of rockets

He saw them as method of travel

He presented the world with a glimpse of the futureDeeply affected the course of rockets

Also published Time travel

Makes you wonder why beards were fashionable back in the day?

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Russia 1883 School Teacher, Konstantin Tsiolkovsky, published famous Rocket Equation in 1903 Considered mad at time now a monument stands in MoscowInfluenced by VerneVery poor and nearly deafWas self educatedPublished over 500 papersTalked about multistage rockets, liquid rockets

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Tsiolkovskys Rocket Equation16

Mission Delta-V RequirementsMission (duration)Delta-V (km/sec)Earth surface to LEO7.6LEO to Earth Escape3.2LEO to Mars (0.7 yrs)5.7LEO to Neptune (29.9 yrs)13.4LEO to Neptune (5.0 yrs)70LEO to alpha-Centauri (50 yrs)30,000

LEO = Low Earth orbit (approx. 274 km)

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Anatomy of the Chemical RocketTsiolkovsky got depressed since it was impossible to him how could one produce so much thrust as required by Verne (moon guy) Until he met Mendeleyev (periodic table guy)They decided the best way is to burn things.All chemical rockets requireOxidizerFuelAll of these guys wore beards

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Modern RocketryChina (300 B.C.)Earliest recorded use of rocketsBlack powderRussia (early 1900s)Konstantin TsiolkovskyOrbital mechanics, rocket equationUnited States (1920s)Robert GoddardFirst liquid fueled rocket (1926)Germany (1940s)Wernher von BraunV-2Hermann Oberth

Wan-Hu who tried to launch himself to the moon by attaching 47 black powder rockets to a large wicker chair!onenew.wordpress.com

Prof. TsiolkovskyDr. Goddard

goddard.littletonpublicschools.net Dr. von Braun

www.britannica.com www.geocities.com

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Space Propulsion System ClassificationsStored GasChemicalElectricAdvanced Electrothermal Electrostatic Electrodynamic Nuclear Solar thermal Laser Antimatter

LiquidSolidHybridPump FedPressure FedMonopropellantBipropellant

Space propulsion systems are classified by the type of energy source used.

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Stored Gas PropulsionPrimary or auxiliary propulsion.High pressure gas (propellant) is fed to low pressure nozzles through pressure regulator.Release of gas through nozzles (thrusters) generates thrust.Currently used for momentum management of the Spitzer Space telescope.Propellants include nitrogen, helium, nitrous oxide, butane.Very simple in concept.

PGas

FillValvePressureGageHigh Pressure IsolationValvePressureRegulatorFilterThrusterPropellant Tank

Low Pressure IsolationValve

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Chemical Propulsion ClassificationsLiquid PropellantPump FedLaunch vehicles, large upper stagesPressure FedSmaller upper stages, spacecraftMonopropellantFuel onlyBipropellantFuel & oxidizerSolid PropellantLaunch vehicles, Space Shuttle, spacecraftFuel/ox in solid binderHybridSolid fuel/liquid oxSounding rockets, X Prize

www.aerospaceweb.org

en.wikivisual.com

news.bbc.co.uk

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Monopropellant SystemsHydrazine fuel is most common monopropellant.N2H4Decomposed in thruster using catalyst to produce hot gas for thrust.Older systems used hydrogen peroxide before the development of hydrazine catalysts.Typically operate in blowdown mode (pressurant and fuel in common tank).

PFuel Fill ValvePressureGageIsolation ValveFilterThrustersPropellant Tank

Nitrogen or helium

Hydrazine

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Monopropellant Systems

www.ampacisp.com

www.aerojet.com

Bipropellant SystemsA fuel and an oxidizer are fed to the engine through an injector and combust in the thrust chamber.Hypergolic: no igniter needed -- propellants react on contact in engine.Cryogenic propellants include LOX (-423 F) and LH2 (-297 F).Igniter requiredStorable propellants include kerosene (RP-1), hydrazine, nitrogen tetroxide (N2O4), monomethylhydrazine (MMH)

FUEL

OX

P

P

Isolation ValvesEngineChamberNozzle

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Liquid Propellant SystemsPump fed systemsPropellant delivered to engine using turbopumpGas turbine drives centrifugal or axial flow pumpsLarge, high thrust, long burn systems: launch vehicles, space shuttleDifferent cycles developed.

Photos history.nasa.govF-1 Engine Turbopump

H-1 Engine TurbopumpF-1 engine turbopump: 55,000 bhp turbine drive 15,471 gpm (RP-1) 24,811 gpm (LOX)A 35x15x4.5 (ave. depth) backyard pool holds about 18,000 gallons of water. How quickly could the F-1 pump empty it?Ans: In 27 seconds!

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Rocket Engine Power CyclesGas Generator CycleSimplestMost commonSmall amount of fuel and oxidizer fed to gas generatorGas generator combustion products drive turbineTurbine powers fuel and oxidizer pumpsTurbine exhaust can be vented through pipe/nozzle, or dumped into nozzleSaturn V F-1 engine used gas generator cycle

www.aero.org/publications/ crosslink/winter2004/03_sidebar3.html

www.answers.com

Rocket Engine Power Cycles - contExpanderFuel is heated by nozzle and thrust chamber to increase energy contentSufficient energy provided to drive turbineTurbine exhaust is fed to injector and burned in thrust chamberHigher performance than gas generator cyclePratt-Whitney RL-10


science.nasa.gov

Rocket Engine Power Cycles - contStaged CombustionFuel and oxidizer burned in preburners (fuel/ox rich)Combustion products drive turbineTurbine exhaust fed to injector at high pressureUsed for high pressure enginesMost complex, requires sophisticated turbomachineryNot very commonSSME (2700 psia)


www.rocketrelics.com

shuttle.msfc.nasa.gov

The Big Engines

F-1 EngineSaturn V1.5 million lbs thrust (SL)LOX/Kerosenewww.flickr.com

Main EngineSpace Shuttle374,000 lbs thrust (SL)LOX/H2 spaceflight.nasa.gov

RD-1701.78 million lbs thrust (SL)LOX/Kerosenewww.aerospaceguide.net

www.nationalmuseum.af.mil Solid Propellant MotorsFuel and oxidizer are in solid binder.Single use -- no restart capability.Lower performance than liquid systems, but much simpler.Applications include launch vehicles, upper stages, and space vehicles.

www.aerospaceweb.org

www.propaneperformance.com

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Ignition SystemLarge solid motors typically use a three-stage ignition systemInitiator: Pyrotechnic element that converts electrical impulse into a chemical reaction (primer)Booster chargeMain charge: A charge (usually a small solid motor) that ignites the propellant grain. Burns for tenths of a second with a mass flow about 1/10 of the initial propellant grain mass flow.

Propellant GrainTwo main catagoriesDouble Base: A homogeneous propellant grain, usually nitrocellulose dissolved in nitroglycerin. Both ingredients are explosive and act as a combined fuel, oxidizer and binderComposite: A heterogeneous propellant grain with oxidizer crystals and powdered fuel held together in a matrix of synthetic rubber binder.Less hazardous to manufacture and handle

Conventional CompositeFuel5-22% Powdered AluminumOxidizer65-70% Ammonium Perchlorate (NH4ClO4 or AP)Binder8-14% Hydroxyl- Terminated Polybutadiene (HTPB)

FuelsAluminum (Al)Molecular Weight: 26.98 kg/kmolDensity: 2700 kg/m3Most commonly usedMagnesium (Mg)Molecular Weight: 24.32 kg/kmolDensity: 1750 kg/m3Clean burning (green)Beryllium (Be)Molecular Weight: 9.01 kg/kmolDensity: 2300 kg/m3Most energetic, but extremely toxic exhaust products

OxidizersAmmonium Perchlorate (AP)Most commonly usedCl combining with H can form HClToxicDepletion of ozoneAmmonium Nitrate (AN)Next most commonly usedLess expensive than APLess energeticNo hazardous exhaust products

BindersHydroxyl Terminated Polybutadiene (HTPB)Most commonly usedConsistency of tire rubberPolybutadiene Acrylonitrile (PBAN)Nitrocellulose (PNC)Double base agent

AdditivesUsed to promoteCuringEnhanced burn rate (HMX)BondingReduced radiation through the grain (darkening)Satisfactory agingReduced cracking

Some More MathsRocket IgnitionEnergy Harnessing SolutionNewtons 3rd LawPerformance calculated through quantities of temperature and pressureCombustion Thermodynamics

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Rocket Performance CalculationsThrust & Specific ImpulseThrust is the amount of force generated by the rocket.Specific impulse is a measure or engine performance (analogous to miles per gallon)Units are seconds

Rocket Equation

Rocket equation assumes no losses (gravity effects, aerodynamic drag). Actually very accurate for short burns in Earth orbit or in deep space!

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Specific Impulse ComparisonStored gasMonopropellant hydrazineSolid rocket motorsHybrid rocketsStorable bipropellantsLOX/LH260-179 sec185-235 sec280-300 sec290-340 sec300-330 sec450 secSpecific impulse depends on many factors: altitude, nozzle expansion ratio, mixture ratio (bipropellants), combustion temperature.This thruster was used on the Viking Lander. It has a specific impulse of about 225 seconds.

www.rocketrelics.com

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COMMON LIQUID ROCKET FUELSMost Common Liquid OxidizersLOXHydrogen PeroxideNitric AcidNitrogen TetroxideLiquid Florine

Most Common Liquid FuelsHydrocarbon fuels (RP1, kerosense, methane)Liquid hydrogenHydrazine (also mono)Unsymmetrical Dimethylhydrazine

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Propellant Calculation ExerciseDetermine the mass of propellant to send a 2500 kg spacecraft from LEO to Mars (0.7 yr mission).Assume the 2500 kg includes the propellant on-board at the start of the burn.Assume our engine has a specific impulse of 310 sec (typical of a small bipropellant engine).Use the rocket equation:

Most of our spacecraft is propellant! Only 383 kg is left for structure, etc! How could we improve this?

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SUMMARY OF KEY EXIT VELOCITY EQUATIONS

For high Ue (for all thermal rockets), desire:Propellants with low molecular weight, MPropellant mixtures with large QR/MHigh combustion chamber pressure, P02

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Rocket Science Govt or Pvt?Rocket science is well.rocket scienceModern Rockets actually started from universitiesSince then, governments have monopolized the field..until recentlyIn 1999, Stanford professors started a startup SPG based on an old rocket technology they made commercially viable..Hybrid Rocket Technology.NASA is now fighting for its spaceSpace flight is now a venture capitalist away

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Types of Rockets3 types of rockets based on fuelsSolid Rocket Motor (SRM)

Liquid Rocket Engine

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Hybrid Rocket EnginesOxidizer is liquid and fuel is solidmostly

So whats so innovative?Well, you can use anything as fuel:Rubber, wax, plastic and even your old Bata shoes47

AdvantagesMechanically simpler, less plumbing, less partsThey are very safe (solid rockets tend to )They are throttlable, restart-able They are very cost effectiveAlmost military application, therefore open to universities and private sector.Still not fully saturated in terms of innovationA hot ;) area of research, easily publishable.A lot of customers (more on this later)

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Hybrid Rockets at DSU49Inspired by my background in Aerospace and SUPARCO, I convinced a group of junior students to design and manufacture Pakistans first hybrid rocket engine.It is now their FYP.It is reusable. Three test fires so far.It is among about 20 rocketry programs in top world universities (MIT, Stanford, TU-M etc)The 2nd Program in Asia!

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Business Oppurtunities51We have in advanced negotiations with three venture capitalists for commercializing this technologyThe current state of TR is at the technology demonstrator stageRocket Assisted Takeoff (RATO) is one application investors have taken keen interest in.Another application is small satellite launch. Hybrids offer a very cheap and affordable way of reaching space and securing orbits (SUPARCO?)

Questions and Comments Welcome52Making science make money is rocket science, but we can do it through FYPs.

Entire project cost PKR 25K. We hacked a lot of university equipment to make ends meet.

Thank you for your patience.

We look forward to your questions.

Engineering

"It isn't exactly Rocket Science" The artsy science of rocket propulsion