Satellite Propulsion System Research Articles

열해석에 의한 인공위성 추진시스템 열설계

Thermal design for satellite propulsion system has been performed. Overall design requirements and the constitution for propulsion system is described. To meet the thermal design requirements, both a primary and a redundant heater circuit, each with two thermostats placed in series, will protect each hydrazine-wetted components, even if one heater circuit fails to operate. Heater power is turned off if any one of these thermostats is opened at its higher sctpoint. Thus, even if one thermostat is failed closed, the second thermostat will turn off the heater. All such components shall be insulated with MLI. Propulsion heater sizing based on the constant worst cold case condition is conducted through thermal analysis. All heaters selected for propulsion components operate to prevent propellant freezing satisfying the thermal requirements for the propulsion subsystem over the worst case average voltage, i.e. 25 volts.br/

인공위성 연료배관의 유압특성 연구

One of the way to derive design parameters of the fuel feeding system in satellite propulsion system is to analyze unsteady flow of liquid propellant (hydrazine). During steady thruster firing the flow rate is constant: if a thruster valve is abruptly shut down among a set of thrusters, pressure spikes much higher than the initial tank pressure occur. This renders the fuel flow unsteady, and the fluid pressure and flow rate to oscillate. If the pressure spikes are high enough, there are possibilities that propellant explosively decomposes, thruster valves we damaged, and adiabatic detonation of the hydrazine propellant is potentially incurred. Reflected shockwaves could also affect the calibration and operation of the pressure transducers. These necessitate the analysis of unsteady flow in the propulsion system design, and pressure behavior inside the propellant line obtained through some governing parameter variation is presented in this work.

Design Analysis of a Satellite Hydrazine Propulsion System

Numerical simulations are conducted to study various features of the key design parameters for a hydrazinebased satellite propulsion system. For the steady-state e uid analysis, a e ow-channel network numerical scheme is used to determine the blowdown proe le and the pressure drops in the propellant line, as well as the blowdown characteristics during theoperation lifetimeofthepropulsion system. For the transient e uid analysis,a theoretical model based on the method of characteristics is solved to simulate the time-dependent transport behavior of the propellante ows.Thepressureresponsesattheinletsofthelatchisolationvalveandthrustervalvesfortheconditions of different thrust force levels, different equipping orie ces, different pipeline lengths, and different open/closed periods in 0.25-s control cycle were studied. Predicted results indicate that better blowdown behaviors can be obtained for a satellite employing a bigger tank because the e xed propellant mass was loaded to the propulsion system. Better performances can also be achieved for smaller thrust level thrusters used on the satellite. When an appropriate orie ce is equipped into the pipeline, the pressure e uctuation can be damped out rapidly and the potential risk of damaging the propulsion components is minimized. An optimum thruster valve opening time of 80 ms for the pulse-mode control is also recommended.

J. Preston Layton 1919–1992: A guiding light in nuclear space power and propulsion

An eventful, highly productive career ended with the death of James Preston (“Pres”) Layton in December 1992. His career in rockets, which spanned 50 years, is a chronology of developments in the U.S. space program. Layton was instrumental in the development of rocket technologies ranging from the first jet-assisted take off (JATO) boosters used on aircraft to space nuclear power and propulsion. His work on JATOs, during World War II, involved both testing of solid-fueled units on naval aircraft in the Pacific and developing advanced liquid-fueled systems at the U.S. Naval Academy's laboratory under the direction of Robert H. Goddard, the father of American rocketry. It was Goddard who inspired Layton to devote his life to rocketry. In 1948, as chief of propulsion for the Glenn L. Martin company, he became crew chief in charge of testing the first big U.S. rocket, the Viking series. Layton subsequently joined the research faculty at Princeton University where he served from 1951 to 1976, taking a brief leave in 1955 to earn a Masters Degree at Purdue University under the direction of Maurice Zucrow, another American rocket pioneer. As Chief Engineer of Princeton's Guggenheim Jet Propulsion Center, he created the nation's foremost university rocket research facilities, where he conducted the first experimental evaluation of liquid ozone as a rocket propellant. Later Layton led Princeton's Advanced Systems and Mission Analysis Laboratory, which conducted pioneering studies of space nuclear power and propulsion systems. During this period, at the Lawrence Livermore National Laboratory (on leave from Princeton), Layton helped develop and test the world's first and only nuclear ram-rocket. During his career, Layton performed many responsible consulting tasks for industry and government in the U.S.A. and abroad. He was chief technical consultant to Mathematica, Inc., whose analyses formed the basis for the current Space Shuttle design. He conducted an AIAA assessment of New Space Transportation Systems; and chaired a projection of space activities into the 2000 to 2020 time period for the National Research Council. More recently, he designed environmental and communications satellite propulsion systems for MATRA Espace and RCA Astro-Electronics. Layton was very active in the American Institute of Aeronautics and Astronautics (AIAA) and the International Astronautical Federation (IAF). In 1985, he served as International Program Committee Chairman of the 35th International Congress in Stockholm. Layton was a Fellow, American Astronautical Society, Associate Fellow of the AIAA, and a Member of the International Academy of Astronautics.

Packed tower aeration strips trichloroethylene from groundwater

Environmental ProgressVolume 4, Issue 2 p. 119-124 Article Packed tower aeration strips trichloroethylene from groundwater Rand L. Gross, Rand L. Gross USAF, Tyndall AFB, Fla. 32403 Captain Randy L. Gross: is an Air Force Bioenvironmental Engineer assigned to the Air Force Engineering And Services Center, Tyndall AFB, Florida. In his current position as Research Environmental Engineer, he conducts research and development into hazardous waste decontamination, recovery, and treatment processes, and environmental restoration methodologies. Prior to this assignment, he developed satellite propulsion systems as a Chemical Systems Engineer at the Air Force Rocket Propulsion Laboratory, Edwards AFB, California. He holds a BS from Virginia Polytechnic Institute & State University and a MS from Clemson University, both in chemical engineering.Search for more papers by this authorStephen G. Termaath, Stephen G. Termaath USAF, Washington, D.C. 20330 Major Stephen G. TerMaath: is the Assistant for Environmental Quality in the Office of the Assistant Secretary of the Air Force. In his previous assignment as Chief, Environmental Engineering Branch at the Engineering and Services Center until 1983, he was the project officer for the research and development described in this article. His academic background includes a BSCE and a MS in Environmental Health Engineering from the University of Texas in Austin, and a PhD from Purdue University in Environmental Engineering.Search for more papers by this author Rand L. Gross, Rand L. Gross USAF, Tyndall AFB, Fla. 32403 Captain Randy L. Gross: is an Air Force Bioenvironmental Engineer assigned to the Air Force Engineering And Services Center, Tyndall AFB, Florida. In his current position as Research Environmental Engineer, he conducts research and development into hazardous waste decontamination, recovery, and treatment processes, and environmental restoration methodologies. Prior to this assignment, he developed satellite propulsion systems as a Chemical Systems Engineer at the Air Force Rocket Propulsion Laboratory, Edwards AFB, California. He holds a BS from Virginia Polytechnic Institute & State University and a MS from Clemson University, both in chemical engineering.Search for more papers by this authorStephen G. Termaath, Stephen G. Termaath USAF, Washington, D.C. 20330 Major Stephen G. TerMaath: is the Assistant for Environmental Quality in the Office of the Assistant Secretary of the Air Force. In his previous assignment as Chief, Environmental Engineering Branch at the Engineering and Services Center until 1983, he was the project officer for the research and development described in this article. His academic background includes a BSCE and a MS in Environmental Health Engineering from the University of Texas in Austin, and a PhD from Purdue University in Environmental Engineering.Search for more papers by this author First published: May 1985 https://doi.org/10.1002/ep.670040213Citations: 21 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume4, Issue2May 1985Pages 119-124 RelatedInformation