DOCSLIB.ORG

Materials for Liquid Propulsion Systems

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Materials for Liquid Propulsion Systems CHAPTER 12 Materials for Liquid Propulsion Systems John A. Halchak Consultant, Los Angeles, California James L. Cannon NASA Marshall Space Flight Center, Huntsville, Alabama Corey Brown Aerojet-Rocketdyne, West Palm Beach, Florida 12.1 Introduction Earth to orbit launch vehicles are propelled by rocket engines and motors, both liquid and solid. This chapter will discuss liquid engines. The heart of a launch vehicle is its engine. The remainder of the vehicle (with the notable exceptions of the payload and guidance system) is an aero structure to support the propellant tanks which provide the fuel and oxidizer to feed the engine or engines. The basic principle behind a rocket engine is straightforward. The engine is a means to convert potential thermochemical energy of one or more propellants into exhaust jet kinetic energy. Fuel and oxidizer are burned in a combustion chamber where they create hot gases under high pressure. These hot gases are allowed to expand through a nozzle. The molecules of hot gas are first constricted by the throat of the nozzle (de-Laval nozzle) which forces them to accelerate; then as the nozzle flares outwards, they expand and further accelerate. It is the mass of the combustion gases times their velocity, reacting against the walls of the combustion chamber and nozzle, which produce thrust according to Newton’s third law: for every action there is an equal and opposite reaction. [1] Solid rocket motors are cheaper to manufacture and offer good values for their cost. Liquid propellant engines offer higher performance, that is, they deliver greater thrust per unit weight of propellant burned. They also have a considerably higher thrust to weigh ratio. Since liquid rocket engines can be tested several times before flight, they have the capability to be more reliable, and their ability to shut down once started provides an extra margin of safety. Liquid propellant engines also can be designed with restart capability to provide orbital maneuvering capability. In some instances, liquid engines also can be designed to be reusable. On the solid side, hybrid solid motors also have been developed with the capability to stop and restart. Solid motors are covered in detail in chapter 11. Liquid rocket engine operational factors can be described in terms of extremes: temperatures ranging from that of liquid hydrogen (-423⁰F) to 6000⁰F hot gases; enormous thermal shock (7000ºF/sec); large temperature differentials between contiguous components; reactive propellants; extreme acoustic environments; high rotational speeds for turbo machinery and extreme power densities. These factors place great demands on materials selection and each must be dealt with while maintaining an engine of the lightest possible weight. 1 This chapter will describe the design considerations for the materials used in the various components of liquid rocket engines and provide examples of usage and experiences in each. 12.2 Liquid Rocket Engines Liquid rocket engines are either mono-propellant or bi-propellant. Mono-propellant engines either use a straight gaseous system or employ a catalyst to decompose the propellant in an exothermic reaction. An example was the reaction control system on the Mercury capsule in which each small thruster used hydrogen peroxide decomposed by a silver catalyst to provide attitude control for the vehicle. [2] Mono-propellant thrusters are usually used only for low thrust systems such as satellite propulsion systems. Bi-propellant systems use either hypergolic propellants or propellants that require a source of ignition. Hypergolic propellants usually are storable, that is, they are sufficiently stable to remain in their tanks for a considerable period of time under normal earth or space conditions. The most commonly used hypergolic propellants are nitric acid, nitrogen tetra oxide (NTO), hydrogen peroxide, mono-methyl hydrazine (MMH), and unsymmetric di-methyl hydrazine (UDMH). Non-hypergolic propellants that have been most commonly used are liquid oxygen, alcohol, kerosene, and liquid hydrogen. Liquid rocket engines differ greatly depending on mission, materials of construction, and launch vehicle design. The four broad categories into which liquid engines may be placed are: 1. first stage or core (booster) engines; 2. upper stage engines; 3. satellite propulsion engines; and 4. attitude control systems. Each of these categories has its own, unique requirements which significantly influence the engine design. In a liquid engine, the fuel and oxidizer propellants must be delivered to the combustion chamber at a pressure significantly greater than that in the combustion chamber. For relatively low thrust engines, (e.g., satellite propulsion or attitude control) this may be done by pressurizing the propellant storage tanks. For higher-thrust, high-performance engines, pumps must be used. To obtain the necessary power to drive high-performance pumps, a turbine drive is needed. To power the turbine, hot gases or high-pressure fluids are needed. There are many methods to provide the gases or fluids to drive the turbines. One of the most common methods is to provide hot gases by tapping off and combusting a small portion of propellants in a separate chamber called a gas generator. Another common method, the expander cycle, utilizes the energy of expanding fuel, heated by the combustion chamber and nozzle, to drive the turbines. Expander cycles require a low vapor pressure propellant, which limits them to propellants such as hydrogen or methane. Another cycle, the staged-combustion cycle, partially combusts almost all of the fuel with a portion of the oxidizer before entering the main combustion chamber where it is mixed with the remaining oxidizer to complete the combustion process. An alternative staged combustion cycle reverses the process by utilizing oxidizer rich pre-combustion with combustion completed by injecting the remaining fuel into the main combustion chamber. This version of staged combustion is favored by Russian designers. [2] Staged combustion is used when large power inputs are required to produce very high combustion chamber pressures (ex. 3000+ psi). No matter what the cycle, ducting is needed for the transfer of propellants to various engine components. To control the flow of propellants, one needs valves that are quick-acting and able to operate against very high pressure fluids. To actuate the valves, hydraulic, pneumatic, or electrical actuators are necessary. A method is needed to uniformly inject and mix the propellants in the combustion chamber to assure uniform, efficient, and stable combustion – this is called the “injector” of the combustion chamber. Unless hypergolic propellants are used, a method to initiate combustion is required - common methods to do this include: the use of a 2 pyrotechnic device; the injection of a hypergolic compound; or the use of spark ignition. A nozzle and sometimes a nozzle extension are needed to capture as much reactive thrust as practical. The combustion chamber and nozzle must be cooled to prevent them from melting from the heat of combustion. Cooling methods include regenerative, dump, film, transpiration, and ablative, or some combination of these. Commonly used for cooling is a double-walled design through which fuel (and sometimes oxidizer) is circulated to extract heat. For directional control of the vehicle, gimbaling of the engine or vanes in the exhaust stream may be used; either of these requires actuators. Sensors are required at key locations to monitor engine performance and make appropriate propellant flow changes or provide for rapid shut down if an anomaly is detected. To manage all this, a control system is needed which usually takes the form of an electronic computer. All of these elements must come together in an efficient, light-weight package which operates smoothly, efficiently, and reliably. The materials of construction are a key element to achieving the goals of performance, reliability, and relatively light weight. 12.2.1 Propellant Selection The choice of propellant combination for a liquid rocket stage is of fundamental importance, since it helps to determine the size, weight, performance characteristics and cost of the resulting vehicle. Liquid rocket propellants can be divided into two broad categories: storable propellants, which are in the liquid state at room temperature and pressure, and cryogens, which must be kept cold to prevent them from boiling. Storable propellants may be kept in the vehicle for extended periods before launch, and many storable propellant combinations are also hypergolic, which means they ignite on contact and do not require an ignition source. Cryogens, on the other hand, offer higher specific impulse (Isp) than storable propellants, and are often used for applications where performance is critical. [3] The selection of propellant combination is influenced by two important factors: the engine’s operating environment (booster or upper stage), and its thrust size. Upper stages have often used liquid hydrogen as a fuel, since the performance benefits of this cryogenic fuel frequently outweigh the difficulty and cost of maintaining it in the liquid state. The performance of upper stage engines is critical, since any loss in efficiency will require more propellants to lift a given payload, impacting the design of both the upper stage and the booster stage which must lift it. For small stages, however, performance has less of an impact on the overall vehicle, and many small engines have been designed to use storable propellants. Booster stages, for which performance is somewhat less critical, often have used RP-1, a refined form of kerosene, or storable fuels such as hydrazine. The denser fuel reduces the physical size of the stage, which is beneficial since the booster stage is the largest stage in the vehicle, and dictates the size of the handling and launch facilities. Stages using either kerosene or hydrogen fuel generally use liquid oxygen, which can be obtained and stored fairly easily, as the oxidizer, while those stages using storable fuels such as hydrazine typically use nitrogen tetra oxide (N2O4) oxidizer, creating a propellant combination that is both storable and hypergolic.
Load more

Recommended publications
  • General Assembly Distr.: General 29 January 2001
    United Nations A/AC.105/751/Add.1 General Assembly Distr.: General 29 January 2001 Original: English Committee on the Peaceful Uses of Outer Space National research on space debris, safety of space objects with nuclear power sources on board and problems of their collisions with space debris Note by the Secretariat* Addendum Contents Chapter Paragraphs Page I. Introduction........................................................... 1-2 2 Replies received from Member States and international organizations .................... 2 United States of America ......................................................... 2 European Space Agency.......................................................... 7 __________________ * The present document contains replies received from Member States and international organizations between 25 November 2000 and 25 January 2001. V.01-80520 (E) 020201 050201 A/AC.105/751/Add.1 I. Introduction 1. At its forty-third session, the Committee on the Peaceful Uses of Outer Space agreed that Member States should continue to be invited to report to the Secretary- General on a regular basis with regard to national and international research concerning the safety of space objects with nuclear power sources, that further studies should be conducted on the issue of collision of orbiting space objects with nuclear power sources on board with space debris and that the Committee’s Scientific and Technical Subcommittee should be kept informed of the results of such studies.1 The Committee also took note of the agreement of the Subcommittee that national research on space debris should continue and that Member States and international organizations should make available to all interested parties the results of that research, including information on practices adopted that had proved effective in minimizing the creation of space debris (A/AC.105/736, para.
    [Show full text]
  • RD-180—Or Bust?
    RD-180—or By Autumn A. Arnett, Associate Editor As it stands, the US could sustain its Bust? manifest for two years with the current supply of RD-180 engines. But a new he United States’ sustained access he doesn’t really know what that R&D engine could take seven or more years to space is in question. Heavily amounts to, but said he is hopeful the to be operational, making LaPlante’s Treliant on the Russian-made En- partnership will mean a new engine on “$64 million question” a “hydra-headed ergomash RD-180 engine to power its the market soon. monster,” in the words of former AFSPC launches, US military space personnel “Three years of development is better Commander Gen. William L. Shelton. are looking for a replacement because than starting at ground zero,” Hyten said. “I don’t think we build the world’s best of the tense and uncertain status of “If we start at ground zero to build a rocket engine,” Shelton said last July. “I American and Russian relations. new engine in the hydrocarbon technology would love for us as a nation to regain the Funds are already being appropriated area we’re fi ve years away from produc- lead in liquid rocket propulsion.” for research and development of a new tion, roughly, maybe four, maybe six. Both LaPlante and Hyten are propo- engine, but Gen. John E. Hyten, com- The one thing you would have to do is nents of the United States continuing to mander of Air Force Space Command, spend the next year or two driving down fund research and development of a new considers the issue to be urgent.
    [Show full text]
  • Delta II Icesat-2 Mission Booklet
    A United Launch Alliance (ULA) Delta II 7420-10 photon-counting laser altimeter that advances MISSION rocket will deliver the Ice, Cloud and land Eleva- technology from the first ICESat mission tion Satellite-2 (ICESat-2) spacecraft to a 250 nmi launched on a Delta II in 2003 and operated until (463 km), near-circular polar orbit. Liftoff will 2009. Our planet’s frozen and icy areas, called occur from Space Launch Complex-2 at Vanden- the cryosphere, are a key focus of NASA’s Earth berg Air Force Base, California. science research. ICESat-2 will help scientists MISSION investigate why, and how much, our cryosphere ICESat-2, with its single instrument, the is changing in a warming climate, while also Advanced Topographic Laser Altimeter System measuring heights across Earth’s temperate OVERVIEW (ATLAS), will provide scientists with height and tropical regions and take stock of the vege- measurements to create a global portrait of tation in forests worldwide. The ICESat-2 mission Earth’s third dimension, gathering data that can is implemented by NASA’s Goddard Space Flight precisely track changes of terrain including Center (GSFC). Northrop Grumman built the glaciers, sea ice, forests and more. ATLAS is a spacecraft. NASA’s Launch Services Program at Kennedy Space Center is responsible for launch management. In addition to ICESat-2, this mission includes four CubeSats which will launch from dispens- ers mounted to the Delta II second stage. The CubeSats were designed and built by UCLA, University of Central Florida, and Cal Poly. The miniaturized satellites will conduct research DELTA II For nearly 30 years, the reliable in space weather, changing electric potential Delta II rocket has been an industry and resulting discharge events on spacecraft workhorse, launching critical and damping behavior of tungsten powder in a capabilities for NASA, the Air Force Image Credit NASA’s Goddard Space Flight Center zero-gravity environment.
    [Show full text]
  • Qualification Over Ariane's Lifetime
    r bulletin 94 — may 1998 Qualification Over Ariane’s Lifetime A. González Blázquez Directorate of Launchers, ESA, Paris M. Eymard Groupe Programme CNES/Arianespace, Evry, France Introduction Similarly, the RL10 engine on the Centaur stage The primary objectives of the qualification of the Atlas launcher has been the subject of an activities performed during the operational ongoing improvement programme. About 5000 lifetime of a launcher are: tests were performed before the first flight, and – to verify the qualification status of the vehicle 4000 during the subsequent ten years. – to resolve any technical problems relating to subsystem operations on the ground or in On-going qualification activities of a similar flight. nature were started for the Ariane-3 and 4 launchers in 1986, and for Ariane-5 in 1996. Before focussing on the European family of They can be classified into two main launchers, it is perhaps informative to review categories: ‘regular’ and ‘one-off’. just one or two of the US efforts in the area of solid and liquid propulsion in order to put the Ariane-3/4 accompanying activities Ariane-related activities into context. Regular activities These activities are mainly devoted to In principle, the development programme for a launcher ends with the verification of the qualification status of the qualification phase, after which it enters operational service. In various launcher subsystems. They include the practice, however, the assessment of a launcher’s reliability is a following work packages: continuing process and qualification-type activities proceed, as an – Periodic sampling of engines: one HM7 and extension of the development programme (as is done in aeronautics), one Viking per year, tested to the limits of the over the course of the vehicle’s lifetime.
    [Show full text]
  • ULA Atlas V Launch to Feature Full Complement of Aerojet Rocketdyne Solid Rocket Boosters
    April 13, 2018 ULA Atlas V Launch to Feature Full Complement of Aerojet Rocketdyne Solid Rocket Boosters SACRAMENTO, Calif., April 13, 2018 (GLOBE NEWSWIRE) -- The upcoming launch of the U.S. Air Force Space Command (AFSPC)-11 satellite aboard a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station, Florida, will benefit from just over 1.74 million pounds of added thrust from five AJ-60A solid rocket boosters supplied by Aerojet Rocketdyne. The mission marks the eighth flight of the Atlas V 551 configuration, the most powerful Atlas V variant that has flown to date. The Atlas V 551 configuration features a 5-meter payload fairing, five AJ-60As and a Centaur upper stage powered by a single Aerojet Rocket RL10C-1 engine. This configuration of the U.S. government workhorse launch vehicle is capable of delivering 8,900 kilograms of payload to geostationary transfer orbit (GTO), and also has been used to send scientific probes to explore Jupiter and Pluto. The Centaur upper stage also uses smaller Aerojet Rocketdyne thrusters for pitch, yaw and roll control, while both stages of the Atlas V employ pressurization vessels built by Aerojet Rocketdyne's ARDÉ subsidiary. "The Atlas V is able to perform a wide variety of missions for both government and commercial customers, and the AJ-60A is a major factor in that versatility," said Aerojet Rocketdyne CEO and President Eileen Drake. "Aerojet Rocketdyne developed the AJ-60A specifically for the Atlas V, delivering the first booster just 42 months after the contract award, which underscores our team's ability to design and deliver large solid rocket motors in support of our nation's strategic goals and efforts to explore our solar system." The flight of the 100th AJ-60A, the largest monolithically wound solid rocket booster ever flown, took place recently as part of a complement of four that helped an Atlas V 541 place the nation's newest weather satellite into GTO.
    [Show full text]
  • High-Thrust In-Space Liquid Propulsion Stage: Storable Propellants
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Institute of Transport Research:Publications Space Propulsion 2014 – ID 2968378 High-Thrust in-Space Liquid Propulsion Stage: Storable Propellants Etienne Dumont, Alexander Kopp, Carina Ludwig, Nicole Garbers DLR, Space Launcher Systems Analysis (SART), Bremen, Germany [email protected] Abstract In the frame of a project funded by ESA, a consortium led Subscripts, Abbreviations by Avio in cooperation with Snecma, Cira, and DLR is ATV Automated Transfer Vehicle performing the preliminary design of a High-Thrust in- CDF Concurrent Design Facility Space Liquid Propulsion Stage for two different types of ECSS European Cooperation on Space manned missions beyond Earth orbit. For these missions, Standardization one or two 100 ton stages are to be used to propel a Elec assy electronic assembly manned vehicle. Three different propellant combinations; EPS Etage à propergols stockables (Ariane 5’s LOx/LH2, LOx/CH4 and MON-3/MMH are being storable propellant stage) compared. GNC Guidance Navigation and Control HTS High-Thrust Stage The preliminary design of the storable variant (MON- IF Interface 3/MMH) has been performed by DLR. The Aestus II ISS International Space Station engine with a large nozzle expansion ratio has been LEO Low Earth Orbit chosen as baseline. A first iteration has demonstrated, that LEOP Launch and Early Orbit Phase it indeed provides the best performance for the storable LH2 Liquid Hydrogen propellant combination, when considering all engines LOx Liquid Oxygen available today or which may be available in a short- to MLI Multi-Layer Insulation medium term.
    [Show full text]
  • Monopropellant System
    ~™ mil ii ii nun mi iiiii iiiii (19) J European Patent Office Office europeen des brevets (11) EP 0 950 648 A1 (12) EUROPEAN PATENT APPLICATION (43) Date of publication:ation: (51) Int. CI.6: C06D 5/08 20.10.1999 Bulletin 1999/42 (21) Application number: 98201190.0 (22) Date of filing: 15.04.1998 (84) Designated Contracting States: (72) Inventors: AT BE CH CY DE DK ES Fl FR GB GR IE IT LI LU • van den Berg, Ronald Peter MC NL PT SE 2291 KJ Wateringen (NL) Designated Extension States: • Mul, Johannes Maria AL LT LV MK RO SI 2013 AE Haarlem (NL) • Elands, Petrus Johannes Maria (71) Applicant: 2804 LK Gouda (NL) NEDERLANDSE ORGANISATIE VOOR TOEGEPAST-NATUURWETENSCHAPPELIJK (74) Representative: ONDERZOEK Smulders, Theodorus A.H.J., Ir. et al TNO Vereenigde Octrooibureaux 2628 VK Delft (NL) Nieuwe Parklaan 97 2587 BN 's-Gravenhage (NL) (54) Monopropellant system (57) The invention is directed to a monopropellant composition for propulsion and/or gas generation, com- prising a solution of hydrazinium nitroformate (HNF) and/or ammonium dinitramide (ADN) in water and/or an alkanol. < CO CO o LO o Q_ LU Printed by Xerox (UK) Business Services 2.16.7/3.6 EP 0 950 648 A1 Description [0001] The present invention is in the area of monopropellant composition systems, for instance for spacecraft pro- pulsion, in emergency systems for jet fighters or in emergency gasgeneration systems for submarines. 5 [0002] Spacecraft propulsion is defined as that needed for the orientation (attitude control) and positioning (orbit con- trol including de-orbiting) of spacecraft after delivery into the required orbit by the launch vehicle.
    [Show full text]
  • Investigation of Condensed and Early Stage Gas Phase Hypergolic Reactions Jacob Daniel Dennis Purdue University
    Purdue University Purdue e-Pubs Open Access Dissertations Theses and Dissertations Fall 2014 Investigation of condensed and early stage gas phase hypergolic reactions Jacob Daniel Dennis Purdue University Follow this and additional works at: https://docs.lib.purdue.edu/open_access_dissertations Part of the Propulsion and Power Commons Recommended Citation Dennis, Jacob Daniel, "Investigation of condensed and early stage gas phase hypergolic reactions" (2014). Open Access Dissertations. 256. https://docs.lib.purdue.edu/open_access_dissertations/256 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. i INVESTIGATION OF CONDENSED AND EARLY STAGE GAS PHASE HYPERGOLIC REACTIONS A Dissertation Submitted to the Faculty of Purdue University by Jacob Daniel Dennis In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy December 2014 Purdue University West Lafayette, Indiana ii To my parents, Jay and Susan Dennis, who have always pushed me to be the person they know I am capable of being. Also to my wife, Claresta Dennis, who not only tolerated me but suffered along with me throughout graduate school. I love you and am so proud of you! iii ACKNOWLEDGEMENTS I would like to express my sincere gratitude to my advisor, Dr. Timothée Pourpoint, for guiding me over the past four years and helping me become the researcher that I am today. In addition I would like to thank the rest of my PhD Committee for the insight and guidance. I would also like to acknowledge the help provided by my fellow graduate students who spent time with me in the lab: Travis Kubal, Yair Solomon, Robb Janesheski, Jordan Forness, Jonathan Chrzanowski, Jared Willits, and Jason Gabl.
    [Show full text]
  • The SKYLON Spaceplane
    The SKYLON Spaceplane Borg K.⇤ and Matula E.⇤ University of Colorado, Boulder, CO, 80309, USA This report outlines the major technical aspects of the SKYLON spaceplane as a final project for the ASEN 5053 class. The SKYLON spaceplane is designed as a single stage to orbit vehicle capable of lifting 15 mT to LEO from a 5.5 km runway and returning to land at the same location. It is powered by a unique engine design that combines an air- breathing and rocket mode into a single engine. This is achieved through the use of a novel lightweight heat exchanger that has been demonstrated on a reduced scale. The program has received funding from the UK government and ESA to build a full scale prototype of the engine as it’s next step. The project is technically feasible but will need to overcome some manufacturing issues and high start-up costs. This report is not intended for publication or commercial use. Nomenclature SSTO Single Stage To Orbit REL Reaction Engines Ltd UK United Kingdom LEO Low Earth Orbit SABRE Synergetic Air-Breathing Rocket Engine SOMA SKYLON Orbital Maneuvering Assembly HOTOL Horizontal Take-O↵and Landing NASP National Aerospace Program GT OW Gross Take-O↵Weight MECO Main Engine Cut-O↵ LACE Liquid Air Cooled Engine RCS Reaction Control System MLI Multi-Layer Insulation mT Tonne I. Introduction The SKYLON spaceplane is a single stage to orbit concept vehicle being developed by Reaction Engines Ltd in the United Kingdom. It is designed to take o↵and land on a runway delivering 15 mT of payload into LEO, in the current D-1 configuration.
    [Show full text]
  • Rocket Propulsion Fundamentals 2
    https://ntrs.nasa.gov/search.jsp?R=20140002716 2019-08-29T14:36:45+00:00Z Liquid Propulsion Systems – Evolution & Advancements Launch Vehicle Propulsion & Systems LPTC Liquid Propulsion Technical Committee Rick Ballard Liquid Engine Systems Lead SLS Liquid Engines Office NASA / MSFC All rights reserved. No part of this publication may be reproduced, distributed, or transmitted, unless for course participation and to a paid course student, in any form or by any means, or stored in a database or retrieval system, without the prior written permission of AIAA and/or course instructor. Contact the American Institute of Aeronautics and Astronautics, Professional Development Program, Suite 500, 1801 Alexander Bell Drive, Reston, VA 20191-4344 Modules 1. Rocket Propulsion Fundamentals 2. LRE Applications 3. Liquid Propellants 4. Engine Power Cycles 5. Engine Components Module 1: Rocket Propulsion TOPICS Fundamentals • Thrust • Specific Impulse • Mixture Ratio • Isp vs. MR • Density vs. Isp • Propellant Mass vs. Volume Warning: Contents deal with math, • Area Ratio physics and thermodynamics. Be afraid…be very afraid… Terms A Area a Acceleration F Force (thrust) g Gravity constant (32.2 ft/sec2) I Impulse m Mass P Pressure Subscripts t Time a Ambient T Temperature c Chamber e Exit V Velocity o Initial state r Reaction ∆ Delta / Difference s Stagnation sp Specific ε Area Ratio t Throat or Total γ Ratio of specific heats Thrust (1/3) Rocket thrust can be explained using Newton’s 2nd and 3rd laws of motion. 2nd Law: a force applied to a body is equal to the mass of the body and its acceleration in the direction of the force.
    [Show full text]
  • L AUNCH SYSTEMS Databk7 Collected.Book Page 18 Monday, September 14, 2009 2:53 PM Databk7 Collected.Book Page 19 Monday, September 14, 2009 2:53 PM
    databk7_collected.book Page 17 Monday, September 14, 2009 2:53 PM CHAPTER TWO L AUNCH SYSTEMS databk7_collected.book Page 18 Monday, September 14, 2009 2:53 PM databk7_collected.book Page 19 Monday, September 14, 2009 2:53 PM CHAPTER TWO L AUNCH SYSTEMS Introduction Launch systems provide access to space, necessary for the majority of NASA’s activities. During the decade from 1989–1998, NASA used two types of launch systems, one consisting of several families of expendable launch vehicles (ELV) and the second consisting of the world’s only partially reusable launch system—the Space Shuttle. A significant challenge NASA faced during the decade was the development of technologies needed to design and implement a new reusable launch system that would prove less expensive than the Shuttle. Although some attempts seemed promising, none succeeded. This chapter addresses most subjects relating to access to space and space transportation. It discusses and describes ELVs, the Space Shuttle in its launch vehicle function, and NASA’s attempts to develop new launch systems. Tables relating to each launch vehicle’s characteristics are included. The other functions of the Space Shuttle—as a scientific laboratory, staging area for repair missions, and a prime element of the Space Station program—are discussed in the next chapter, Human Spaceflight. This chapter also provides a brief review of launch systems in the past decade, an overview of policy relating to launch systems, a summary of the management of NASA’s launch systems programs, and tables of funding data. The Last Decade Reviewed (1979–1988) From 1979 through 1988, NASA used families of ELVs that had seen service during the previous decade.
    [Show full text]
  • 6. Chemical-Nuclear Propulsion MAE 342 2016
    2/12/20 Chemical/Nuclear Propulsion Space System Design, MAE 342, Princeton University Robert Stengel • Thermal rockets • Performance parameters • Propellants and propellant storage Copyright 2016 by Robert Stengel. All rights reserved. For educational use only. http://www.princeton.edu/~stengel/MAE342.html 1 1 Chemical (Thermal) Rockets • Liquid/Gas Propellant –Monopropellant • Cold gas • Catalytic decomposition –Bipropellant • Separate oxidizer and fuel • Hypergolic (spontaneous) • Solid Propellant ignition –Mixed oxidizer and fuel • External ignition –External ignition • Storage –Burn to completion – Ambient temperature and pressure • Hybrid Propellant – Cryogenic –Liquid oxidizer, solid fuel – Pressurized tank –Throttlable –Throttlable –Start/stop cycling –Start/stop cycling 2 2 1 2/12/20 Cold Gas Thruster (used with inert gas) Moog Divert/Attitude Thruster and Valve 3 3 Monopropellant Hydrazine Thruster Aerojet Rocketdyne • Catalytic decomposition produces thrust • Reliable • Low performance • Toxic 4 4 2 2/12/20 Bi-Propellant Rocket Motor Thrust / Motor Weight ~ 70:1 5 5 Hypergolic, Storable Liquid- Propellant Thruster Titan 2 • Spontaneous combustion • Reliable • Corrosive, toxic 6 6 3 2/12/20 Pressure-Fed and Turbopump Engine Cycles Pressure-Fed Gas-Generator Rocket Rocket Cycle Cycle, with Nozzle Cooling 7 7 Staged Combustion Engine Cycles Staged Combustion Full-Flow Staged Rocket Cycle Combustion Rocket Cycle 8 8 4 2/12/20 German V-2 Rocket Motor, Fuel Injectors, and Turbopump 9 9 Combustion Chamber Injectors 10 10 5 2/12/20
    [Show full text]