1 MOSCOW, 30 October 2009 (Itar‐Tass) ‐‐ The self‐induced blast of a Tochka‐U tactical missile during the Thursday (Oct 29) shooting practice at the Leningrad military district's Luga training range might have resulted from the missile's engine failure, Rocketry and Artillery Forces Commander Lt. Gen. Sergei Bogatinov said. "The missile really blasted shortly after the takeoff. No one was hurt, and there was no damage. The launcher is intact. The main theory of this incident is a failure of the missile's engine," he said...
2 1. A missile is a collection of systems, subsystems, and components working toward a common purpose, just like an automobile or any other piece of complex machinery •The various subsystems are typically designed, developed and tested independently, and then integrated into a final product •Designers want the newest and best, but often settle for what works, what’s available and what they can afford. 2. We will address the major subsystems that comprise a missile, and consider the materials and equipment needed for production •The STRUCTURE supports and protects the warhead, and provides the carriage by which the warhead is delivered to its destination. Designers want this to be as strong and light as possible, all balanced against cost (materials, availability, manufacturability, supportability, lifespan). •The GUIDANCE system contains those subsystems needed to guide the weapon to its intended target. Designers want these to be as compact, reliable, accurate and efficient as possible. This is again balanced against cost, availability, and complexity. [“Rockets” have no guidance; “Scuds” barely have guidance.] •The PROPULSION system drives the weapon to its target. Designers want high thrust and propulsion efficiency (Specific Impulse, or Isp), but there are limits to how much propellant can be carried, how much internal pressure and heat can be withstood, and how long the engine‐motor can function. 3. Last but not least are the TEST EQUIPMENT needed to ensure the missile will work, and the LAUNCH SUPPORT equipment needed to field, support, and launch these systems.
3 • Rockets and missiles have a finite life span. Well‐made rockets and missiles can last for ten to 20 years, perhaps extended by another five to ten years after robust examination and testing. Poorly‐made rockets and missiles have a much shorter life span; perhaps cut in half. • “Time” inescapably moves us along the missile’s life timeline; “Damage” reduces the length of the timeline. We will talk about that damage and its affects, such as environmental and handling factors, or the fundamental nature of the rocket itself. • Beyond “age” factors, we must be reminded that there are agreements, treaties, or political decisions under which unneeded, expired, or otherwise unsafe rockets and missiles can be demolished.
4 (Flood Photo: Hnin Maung) (Mist photo: Quang‐Tuan Luong )
• What decreases rocket and missile life? • First, there are the environmental factors of heat and water. • Heat dramatically alters the burn behavior of the propellants (liquid or solid). • Heat boosts the chamber pressure and temperature, sometimes higher than the capacity of the motor case. • Solid motors absorb water. When the burn surface approaches the water, the water boils or flash steams, causing surface blow‐outs, increasing the burn pressure, flashing more water, etc. • This can cause high‐frequency pressure fluctuations that can break off chunks of propellant, or fail the nozzle or motor case structure. • Temperature fluctuations damage motor grains by inducing internal stresses. • Motor grain is a rubber‐like insulator. Temperature jumps from up‐down on aircraft, or mountain excursions, or day‐night cycles repeatedly subject the motor to these stresses (I’ll show an illustration in a moment). • Salt hurts everything, by corrosion. • Design margins driven as low as possible to save weight, or compromised by poor‐quality construction, don’t allow for much in the way of strength reduction. • Oh, and liquid propellants collect environmental contaminants from supply tanks, feed lines, etc.
5 • Let’s talk about solid propellants. • Basically, they are explosive compounds that burn at a very rapid rate, but not nearly as fast as “detonation.” • For rocket and missile propellant, there are two basic types: • Homogeneous –essentially all in the same large molecule • These are air‐to‐air missiles, surface‐to‐air missiles, most rockets… • Heterogeneous –remain as separate molecules, bound together • These are ballistic missiles, some rockets… • Higher performing, but a smoky plume… • In addition to temperature and humidity damage, the elastic propellant sloughs due to the constant pull of gravity; the chemical ingredients decompose into original molecules; plasticizer (the ingredient giving it the elastic texture) tends to migrate through and out of the grain. • Look at the figure to the right, which shows how even a few months can cause propellant ingredients to migrate sufficient to be observed in X‐rays. • All of this damage is irreversible; plus motors are damaged by rough handling.
6 • The left figure (a slice through the solid propellant grain) shows how a grain burns back from the original star‐shaped perforation/void, out to the motor case liner.
• A different grain is shown on the right to illustrate how internal defects, as small as they might be, can affect burn back. The investigators burned the motor for a brief span, and then rapidly extinguished the burn. • The red line is the original star shape. • The yellow‐green line is what the burn line should look like. • You can see where the burn surface deviates from that yellow‐green line. • These are areas where density differences, voids, cracks, or other defects have locally affected the burn. • If there are enough defects, or severe enough defects, motor grain failure results, which vastly over‐pressurizes the motor case, leading to motor case rupture.
• Defects, such as these, occur as a result of the mixing, casting, curing –the quality of the production process. They also occur as a consequence of age.
7 • So, you thought liquid‐propelled rocket systems can avoid problems… I assure you that they cannot.
• Liquids are just as problematic, especially sensitive to the quality of manufacture, plus time remains an enemy. • Parts that should slip, slide, and roll are subject to corrosion or foreign particle contamination. • Rubber and plastic parts become brittle and crack or split. Connectors and wire insulators fail. • Springs attain a set (out of calibration). • Explosives used to drive valves that start and stop the engine can become overly sensitive.
8 • Propulsion system failures remain the easiest to point to in terms of quality, age, and environmental degradation, but any of us who’ve repaired old cars or aircraft know, the other systems, subsystems, components also can be compromised.
• You gradually face more risk that your weapon system will fail than the target faces a risk of equipment success. The result is that you lose trust in your equipment. You must come to terms with
• Other easy examples:
• Warheads: Materials swelling, organic components reacting, corrosion, material incompatibilities, plasticizer migration, binder degradation
9 • 9k52 Luna (70 with air brake) • 9k58 Smerch (90 w/o air brake; 70 with air brake) • HY‐1 (Silkworm) • Bal‐E with Kh‐35E
• Independent of the hazards of environment, age, build quality, and handling…
• We must also recognize the realities of obsolescence combined with decisions to eliminate old, unsafe, and obsolete missile and rocket systems.
• In light of what we’ve discussed, I hope you have a new appreciation for why I say that there is no need to retain old and unsafe equipment, especially as it jeopardizes your own crews and civilians.
• Whether your decisions are driven by commitments to agreements or treaties, political or military signaling (e.g., acts of good faith), or purely safety and security rationale –decisions to eliminate are sound and practical.
10 • Missile KSAs are an enabler for long‐range WMD delivery. • This is also true for unguided and guided rockets, cruise missiles and other unmanned aerial systems. • The Hague CoC addresses the two principal paths of proliferation. 1. Vertical –A country acquiring or building better or more missiles; and 2. Horizontal –A country spreading the knowledge, technologies, production infrastructure, and materials to design, construct, and field missile systems. • Combating proliferation can occur at many levels, from entire systems down to the smallest component. • Standing at the forefront or assisting partners. • Fighting knowledge and technology transfers as much as physical goods. • Fighting financial transfers among members of the proliferation networks CONSISTENCY – • Consistent application of pressure on proliferators –eliminate bypasses • Consistent interpretation of treaties, regimes, agreements –eliminate potential gaps • Global implementation of same –plug any remaining holes
11 12 HCoC subscribing states make voluntary commitments… General Measures: Abide by HCoC principles and accede to UN Space Treaties & Declarations Transparency Measures: Submit an annual declaration of the country’s ballistic missile and space‐launch vehicle programs Confidence‐Building Measures: Provide pre‐ launch notifications on ballistic missile and space‐launch vehicle launches and test flights
• As agreed by the conference in The Hague, Austria serves as the Immediate Central Contact (Executive Secretariat) and therefore coordinates the information exchange within the HCOC framework. • Austria has been named Immediate Central Contact (ICC) for collecting and disseminating Confidence Building Measures submissions, as well as for receiving
13 and announcing subscription of additional states. • The Hague Code of Conduct is a not legally binding instrument. Participation to this code is voluntary and open to all states. • Recognizing the rights of all states to use the benefit of outer space for peaceful purposes, subscribing states are required to implement some general measures, transparency measures (among them annual declarations about their national Ballistic Missiles programmes) and confidence building measures (exchange of pre‐launch notifications on their Ballistic Missiles, Space Launch Vehicles launches and test flights). • For more information please contact the Immediate Central Contact (Executive Secretariat): Austrian Federal Ministry for Europe and Integration and International Affairs Department of Arms Control, Disarmament, and Non‐Proliferation Minoritenplatz 8 1014 Vienna (Austria) ph: +43 5 01150 3247 fax: +43 5 01159 3247 e‐mail: hcoc(at)bmeia.gv.at http://www.hcoc.at
13 • MTCR • www.mtcr.info
14 • MTCR • www.mtcr.info
15 • Wassenaar Arrangement • www.wassenaar.org
16 • MTCR • www.mtcr.info • Wassenaar Arrangement • www.wassenaar.org
17 18 19 20 21 22 Meyer, R; Explosives; 3rd Edition; Essen, Germany; WASAGCHEMIE; 1987
• Here’s where propellants fall under explosive compounds. • They have a lower combustion rate than explosives, when pressure is controlled by way of nozzle out‐flow. • It is that nozzle out‐flow that separates the behavior on the lower left from the lower right. • It is the pristineness of, the lack of internal or external damage to, the rocket motor that also aids to prevent the behavior on the lower right.
• It is important to recognize that rockets and missiles also contain other explosive components that also experience age‐, environmental‐, and handling‐related damage. • Example: Fuze – Initiator(s) – Booster(s) –Main Explosive Charge • Example: Stage separation charges • Example: Main engine ignitors • Example: Solid propellant gas generators to start liquid engines or drive pneumatics, hydraulics, etc.
23 Meyer, R; Explosives; 3rd Edition; Essen, Germany; WASAGCHEMIE; 1987
• And here a the breakdown of rocket propellants. • Example: Pechora (SA‐3) uses a cartridge‐loaded double‐base solid‐propellant rocket motor to rapidly boost the system and a cartridge‐loaded slower‐burning double‐base solid‐propellant sustainer stage. • Example: Volga (SA‐2) uses a multi‐stick double‐base solid‐propellant booster to quickly get the missile up to speed, and starts the hypergolic storable‐liquid‐ propellant sustainer engine.
24 • Missile and rocket users tend to think of solids as something they buy and can forget about until it’s time to launch them. I assure you that these systems require consistent care and attention to ensure they function as desired rather than explode like a bomb. • This figure applies to most of your artillery rockets and SAM systems.
• Solid‐propellant rocket motors may seem to be simple, but they have many complicated features needed to provide required thrust while mitigating explosion risk. • Keep the pressure inside the motor case • Smoothly flow the effluent out the nozzle • Prevent over‐stress • Prevent melt‐ or burn‐through
• High‐stress regions can suffer damage over time, and as a consequence of rough handling.
• Failure at any feature in this motor can cause catastrophic motor failure.
25 • This figure illustrates how damage accumulates over time. Starting at perfect (lower figure, zero value).
• Referring to the upper figure, the motor acquires internal damage from internal stresses, exacerbated by temperature fluctuations, the constant pull of gravity, handling stresses, and finally, the firing process itself.
• Back to the lower figure, thus even the perfect motor (i.e., there were no production defects) acquires damage gradually, but this is an irreversible process. Damage to the grain does not self‐heal. • The difference between high‐quality/well‐cared‐for and low‐quality/poorly‐ cared‐for is the rate of damage accumulation
26 • Lapse rate (dry air) ~ 10C / km altitude • Lapse rate (moist air) is a lower rate (thicker air retains temperature easier than dry air)
• Solar flux raises temperature of the motor case to even higher temperatures –perhaps another 10‐25 degreeC • How much does temperature affect motor burn characteristics? • In this (British) study, propellant conditioned to room temperature (22C) is subjected to 43C (110F) for varying time, then burned to measure chamber pressure. The results are shown in this plot. • Measured temperature indicates the time needed to penetrate the grain (it is a rubber‐like insulator –pencil eraser, but black to block radiative pre‐heating • Mostly, this illustrates that a typical design margin (1.15 to 1.25) can be used up in 2 to 4 hours. Higher margins are possible, but at much heavier weight. • After a few days, the grain must be re‐conditioned –of course adding to the accumulated damage.
27 For this example, • 100psi shear stress fails in ~14 hours • 10psi shear stress fails in ~19 hours • 1psi shear stress fails in ~26 hours • 0.1psi shear stress fails in ~37 hours • 0.01shear stress fails in ~50 hours
• Here, we illustrate damage due to gravity, or any other nearly‐continuous loading.
• Sutton shows that a constant shear load leads to mechanical failure of the bond, irrespective of the shear magnitude.
• It is for this reason that special care must be taken in the storage and handling of solid rocket motors.
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