SNS COLLEGE OF TECHNOLOGY (An Autonomous Institution) DEPARTMENT OF AERONAUTICAL ENGINEERING Subject Code & Name: 16AE409 ROCKETS AND MISSILES Date: 16.08.19 DAY: 01 UNIT: 4: STAGING OF ROCKETS AND MISSILES TOPIC: 1: TWO MARK QUESTION & ANSWER 1. Define multistage rocket. A multistage (or) multistep rocket is a series of individual vehicles or stages each with its own structure, tanks and engines. The stages are so connected that each operates in turn accelerating the remaining stages and the payload before being detached from them. 2. Nomenclature of the multistage rocket. 3. Write the different types of stage separation techniques. 1. By helical compression springs 2. By short duration solid propellant rockets. 4. Separation of stages with in the atmosphere The burnout of the first stage generally occurs within the upper region of the atmosphere i) Firing in the hole technique ii) Ullage rocket techniques. 5. Advantages of Multistage rocket design. Higher payload Enough to accelerate the initial mass Long-range Easy thrust programming K.NEHRU, M.Tech.,(Ph.D) Assistant Professor 16AE409 ROCKETS AND MISSILES 6. Write the expression for sub rocket 1 and (i+1). Sub rocket 1 = Complete rocket Sub rocket (i+1) = sub rocketi - stagei 7. Write the expression for payload of sub rocket 1 and N. Payload sub rocket i = Sub rocket (i+1) Payload sub rocket N = Actual payload 8. Sketch the thrust to time variation graph of stage separation techniques. i) Firing in the hole technique i) Ullage rocket techniques. 9. Drawbacks of firing in the hole techniques. K.NEHRU, M.Tech.,(Ph.D) Assistant Professor 16AE409 ROCKETS AND MISSILES 1. Care must be taken that adequate ventilation holes 2. Risk of tanks 10. Define thrust to weight ratio. Thrust to weight ratio = Lift off thrust / Initial launch vehicle = Tlo / Wo 11. Define Growth factor. Growth factor = Initial launch weight / Payload weight = W0 / Wfl Growth factor gives the efficiency of the design. 12. Write about GSLV. Geosynchronous Satellite Launch Vehicle Mark II (GSLV Mk II) is the largest launch vehicle developed by India, which is currently in operation. This fourth generation launch vehicle is a three stage vehicle with four liquid strap-ons. The indigenously developed cryogenic Upper Stage (CUS), which is flight proven, forms the third stage of GSLV Mk II. From January 2014, the vehicle has achieved four consecutive successes. 13. List the GSLV vehicle specification. Vehicle Specifications Height : 49.13 m Number of Stages : 3 Lift Off Mass : 414.75 tonnes First Flight : April 18, 2001 14. Write the technical specification of GSLV Payload to GTO. Payload to GTO: 2,500 kg GSLV's primary payloads are INSAT class of communication satellites that operate from geostationary orbits and hence are placed in Geosynchronous Transfer Orbits by GSLV. K.NEHRU, M.Tech.,(Ph.D) Assistant Professor 16AE409 ROCKETS AND MISSILES 15. Write the technical specification of GSLV Payload to LEO. Payload to LEO: 5,000 kg Further, GSLV's capability of placing up to 5 tone’s in Low Earth Orbits broadens the scope of payloads from heavy satellites to multiple smaller satellites. 16. Write the technical specification of GSLV third stage. Third Stage: CUS Developed under the Cryogenic Upper Stage Project (CUSP), the CE-7.5 is India's first cryogenic engine, developed by the Liquid Propulsion Systems Centre. CE-7.5 has a staged combustion operating cycle. Fuel : LOX + LH2 Max. Thrust : 75 kN Burn-time : 720 sec 17. Write the technical specification of GSLV second stage. Second Stage: GS2 One Vikas engine is used in the second stage of GSLV. The stage was derived from the PS2 of PSLV where the Vikas engine has proved its reliability. Engine : Vikas Fuel : UDMH + N2O4 Max. Thrust : 800 kN Burntime : 150 sec 18. Write the technical specification of GSLV first stage. First Stage: GS1 The first stage of GSLV was also derived from the PSLV's PS1. The 138 tonne solid rocket motor is augmented by 4 liquid strap-ons. Engine : S139 Fuel : HTPB Max. Thrust : 4700 kN Burntime : 100 sec 19. Write the technical specification of GSLV Engine. Strap-on Motors K.NEHRU, M.Tech.,(Ph.D) Assistant Professor 16AE409 ROCKETS AND MISSILES The four liquid engine strap-ons used in GSLV are heavier derivatives of PSLV's PS2, and use one Vikas engine each. Fuel : UDMH + N2O4 Max. Thrust : 680 kN Burntime : 160 sec 20. Define. i) Payload ratio (λ) = Mu / M0 = Payload Mass / Initial Mass ii) Structural Efficiency (£) = Mc / [Mc + Mp] = Structural Mass / [Structural Mass + Propellant Mass] iii) Propellant Ratio (ᶲ) = Mp/Mo = Propellant Mass / Initial Mass iv) Empty Mass (Me) = Mo * Mp = Initial Launch Mass * Propellant Mass v) Mass Ratio (˄) = M0 / Me = Initial Mass / Empty Mass vi) Specific Thrust (β) = F/ g0 M vii) Trust to weight ratio (ψ0) = F/ g0 M Mass Ratio (˄) = 1 / {£ [1- λ] + λ} K.NEHRU, M.Tech.,(Ph.D) Assistant Professor 16AE409 ROCKETS AND MISSILES .