（ http://www.spacemart.com/reports/USAF_Eyes_Mini_Thrusters_For_Use_In_Satellite_Propulsion_999.html ） USAF Eyes Mini-Thrusters For Use In Satellite Propulsion A prototype of a miniature electrospray thruster with four rows of ion emitters is shown here. The thruster is contained within two black plates each measuring about one square inch. Credit: Credit: Dr. Paulo Lozano, MIT by Staff Writers Wright Patterson AFB OH (SPX) Mar 04, 2010 Mini- thrusters or miniature, electric propulsion systems are being developed, which could make it easier for the Air Force's small satellites, including the latest CubeSats, to perform space maneuvers and undertake formidable tasks like searching for planets beyond our solar system . With Air Force Office of Scientific Research funding, researchers led by Dr. Paulo Lozano at Massachusetts Institute of Technology are considering the advantages of electric propulsion over more traditional chemical rocketry. As a result, they have discovered ionic liquid ion sources which are the core elements of the mini-thruster. In addition to the benefits anticipated for small satellites, the technology may have applicability in completely different areas. Fast-moving ions coming out from the mini-thrusters can be used to etch semiconductors to create patterns in the nanometer scale, to fabricate computer chips or small mechanical devices, said Lozano. The team is interested in the properties that allow advances in travel between different orbits in space and the ability for spacecraft to self-destruct upon controlled re-entry, therefore preventing the creation of additional space debris. Lozano predicts that he will have a mini-thruster prototype developed in about four or five months and he expects the technology to become a reality in the next two years. He plans to begin measuring the velocity of the ions and their energy as soon as the prototype is ready to determine the thrust and efficiency of the engine. Later this year, the team will begin looking at how to integrate mini-thrusters to flight hardware. （ http://www.space.cetin.net.cn/index.asp?modelname=new_space%2Fnews_nrFractionNo=titleno=XWEN0000recno=65734 ） 美国空军着眼于将迷你推力器用于卫星推进 新闻发布时间：2010-03-04 迷你推力器或小型电推进系统正在开发中，它们将使得空军的小卫星（如最新的立方体卫星）更易执行太空机动，并完成像寻找太阳系外行星这样艰巨的任务。 利用美国空军科学研究办公室的资金，由美国麻省理工学院罗扎诺博士领导的研究人员，正在考虑电推进与传统化学火箭相比具有的优势。结果，他们发现“离子性液体离子源”是迷你推力器的核心元素。 迷你推力器可使太空中的航天器在不同轨道间移动，也能够让航天器在受控再入时自毁，由此防止产生额外的太空垃圾。除了应用于小卫星，此项技术还可能应用于完全不同的领域。产生于迷你推力器的快速移动离子能被用于蚀刻半导体，由此创造出纳米级模式，制造计算机芯片或小型化学装置。 罗扎诺博士预测，在未来4或5个月内将开发出迷你推力器的样机，他希望此项技术在未来2年将变为现实。他计划一旦确定了样机发动机的推力和效率，就开始测量离子的速度和它们的能量。今年晚些时候，该团队将开始考虑如何将迷你推力器集成到飞行硬件上。（中国航天工程咨询中心 谢慧敏 郭多娴）
日本宇宙航空研究开发机构（JAXA）3月12日宣布，日本将在2010年5月18日发射的伊卡洛斯号卫星上首次空间验证太阳帆推进技术。 太阳帆推进是一种新型的无工质推进技术（即不需要携带任何推进剂），依靠反射太阳光光子而产生推力。 （ http://www.jaxa.jp/projects/sat/ikaros/index_e.html ） March 11, 2010 Updated Solar Sail IKAROS x LightSail Message Campaign Extended until March 22 (Vernal Equinox Day) The collaborative message campaign held for JAXA's IKAROS satellites and The Planetary Society's LightSail-1 mission has been extended until March 22, (Monday and a holiday in Japan for Vernal Equinox Day.) The registered names and messages will be recorded either on an aluminum plate or DVD to be loaded onto the IKAROS, and travel through space toward the Venus orbit. Those who have not registered, don't miss this opportunity! Space yacht accelerated by radiation of the Sun A Solar Sail gathers sunlight as propulsion by means of a large membrane while a Solar Power Sail gets electricity from thin film solar cells on the membrane in addition to acceleration by solar radiation. What's more, if the ion-propulsion engines with high specific impulse are driven by such solar cells, it can become a hybrid engine that is combined with photon acceleration to realize fuel-effective and flexible missions. JAXA is studying two missions to evaluate the performance of the solar power sails. The project name for the first mission is IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun). This craft will be launched with the Venus Climate Orbiter AKATSUKI, using an H-IIA launch vehicle. This will be the world's first solar powered sail craft employing both photon propulsion and thin film solar power generation during its interplanetary cruise. Vast, thin, and strong solar sail A solar sail can move forward without consuming propellant as long as it can generate enough energy from sunlight. This idea was born some 100 years ago, but it had lots of technical hurdles such as the appropriate material and deployment method for the sail. Recently, we have finally seen some prospect of using this technology practically. The sail of the IKAROS is a huge square some 20 meters in a diagonal line, as thin as 0.0075 mm, and made from polyimide resin. On the membrane of the sail are not only thin film solar cells but also an attitude control device and scientific observation sensors. This thin and light solar sail membrane will be deployed using the centrifugal force of spinning the main body of the IKAROS before its tension is maintained. The deployment is in two stages. The first stage is carried out quasi-statically by the onboard deployment mechanism on the side of the main body. The second stage is the dynamic deployment. As this deployment method does not require a strut such as a boom, it can contribute to making it lighter, thus can be apply for a larger membrane.
（ http://www.marsdaily.com/reports/Scientist_eyes_39-day_voyage_to_Mars_999.html ） Scientist eyes 39-day voyage to Mars By Jean-Louis Santini Washington (AFP) Feb 26, 2010 Franklin Chang-Diaz, a former astronaut and a physicist at the Massachusetts Institute of Technology (MIT), says reaching the Red Planet could be dramatically quicker using his high-tech VASIMR rocket, now on track for liftoff after decades of development. The Variable Specific Impulse Magnetoplasma Rocket -- to give its full name -- is quick becoming a centerpiece of NASA's future strategy as it looks to private firms to help meet the astronomical costs of space exploration. NASA, still reeling from a political decision to cancel its Constellation program that would have returned a human to the moon by the end of the decade, has called on firms to provide new technology to power rovers or even future manned missions. Hopes are now pinned on firms like Chang-Diaz's Texas-based Ad Astra Rocket Company. In the early days... NASA support for the project was rather minimal because the agency did not emphasize advanced technologies as much as it's doing now, Chang-Diaz told AFP. NASA was focused instead on the series of Apollo missions that delivered men to the moon for the first, and so far last, times. They were mesmerized by the Apollo days and lived in the Apollo era for 40 years, and they just forgot developing something new, he said. Chang-Diaz, 60, hopes that something is a non-chemical rocket that eventually allow for a manned trip to Mars -- long the Holy Grail for Apollonians. His rocket would use electricity to transform a fuel -- likely hydrogen , helium or deuterium -- into plasma gas that is heated to 51.8 million degrees Fahrenheit (11 million degrees Celsius). The plasma gas is then channeled into tailpipes using magnetic fields to propel the spacecraft . That would send a shuttle hurtling toward the moon or Mars at ever faster speeds up to an estimated 35 miles (55 kilometers) per second until the engines are reversed. Chang-Diaz, a veteran of seven space missions, said this rapid acceleration could allow for trips of just 39 days instead of the current anticipated round trip voyage to Mars that would last three years, including a forced stay of 18 months on the Red Planet, as astronauts await an opening to return to Earth. The distance between the Earth and Mars varies between 35 and 250 million miles (55 million and 400 million kilometers) depending on their points of orbit. And the use of ionized fuel could have the extra benefit of helping create a magnetic field around the spacecraft to protect against radiation. Scaled-down models of the VASIMR craft have been built and tested in a vacuum, under a deal with NASA. The next major step, according to Chang-Diaz, will be orbital deployment at the end of 2013 of a vessel using the 200-kilowatt prototype VASIMR engine, the VX-200. Talks are underway with fellow space firms SpaceX and Orbital Science Corp to make that a reality. Despite the hurdles ahead, Chang-Diaz sees the potential for a vast market for his technology -- maintaining and repairing fixing satellites or launching robotic and commercial missions to Mars. His rocket may just launch NASA's brave new, commercial, world of space exploration. A journey from Earth to Mars could in the future take just 39 days -- cutting current travel time nearly six times -- according to a rocket scientist who has the ear of the US space agency.
Fundamentals of Electric Propulsion Ion and Hall Thrusters 内容提要： 本书主要介绍了离子推力器和霍尔推力器的主要基本理论及其在空间推进中的应用。大致内容分为以下几个部分：一、介绍了电推进技术的背景，原理以及相关等离子物理的基础知识；二、介绍了离子推力器中等离子体产生机制、加速机制、栅极系统以及空心阴极等主要结构和组成等；三、介绍了霍尔推力器的基本原理、性能以及物理测试模型等。最后还介绍了离子推力器和霍尔推力器羽流的基本特性及其飞行测试状况。 书籍下载（五个压缩包）： Part 1 Part 2 Part 3 Part 4 Part 5
http://www.spacemart.com/reports/Better_Electric_Propulsion_May_Boost_Satellite_Lifetimes_999.html Better Electric Propulsion May Boost Satellite Lifetimes Researchers Jud Ready and Mitchell Walker prepare a carbon nanotube field emitter sample for measurements in the High-Power Electric Propulsion Laboratory of Georgia Tech's School of Aerospace Engineering. Georgia Tech Photo: Gary Meek by Staff Writers Atlanta GA (SPX) Oct 27, 2009 Researchers at the Georgia Institute of Technology have won a $6.5 million grant to develop improved components that will boost the efficiency of electric propulsion systems that are used to control the positions of satellites and planetary probes . Focusing on improved cathodes for devices known as Hall effect thrusters, the research would reduce propellant consumption in commercial, government and military satellites, allowing them to remain in orbit longer, be launched on smaller or cheaper rockets, or carry larger payloads. Sponsored by the U.S. Defense Advanced Research Projects Agency Defense Sciences Office (DARPA-DSO), the 18-month project seeks to demonstrate the use of propellant-less cathodes with Hall effect thrusters. About 10 percent of the propellant carried into space on satellites that use an electric propulsion system is essentially wasted in the hollow cathode that is part of the system, said Mitchell Walker, an assistant professor in Georgia Tech's School of Aerospace Engineering and the project's principal investigator. Using field emission rather than a hollow cathode, we are able to pull electrons from cathode arrays made from carbon nanotubes without wasting propellant. That will extend the life of the vehicle by more efficiently using the limited on-board propellant for its intended purpose of propulsion. To maintain their positions in space or to reorient themselves, satellites must use small thrusters that are either chemically or electrically powered. Electrically-powered thrusters use electrons to ionize an inert gas such as xenon. The resulting ions are then ejected from the device to generate thrust. In existing Hall effect thrusters, a single high-temperature cathode generates the electrons. A portion of the propellant - typically about 10 percent of the limited supply carried by the satellite - is used as a working fluid in the traditional hollow cathode. The DARPA-funded research would replace the hollow cathode with an array of field-effect cathodes fabricated from bundles of multi-walled carbon nanotubes . Powered by on-board batteries and photovoltaic systems on the satellite, the arrays would operate at low power to produce electrons without consuming propellant. Walker and collaborators at the Georgia Tech Research Institute (GTRI) have already demonstrated field-effect cathodes based on carbon nanotubes. This work was presented at the 2009 AIAA Joint Propulsion Conference held in Denver, Colo. The additional funding will support improvements in the devices, known as carbon nanotube cold cathodes, and lead to space testing as early as 2015. This work depends on our ability to grow aligned carbon nanotubes precisely where we want them to be and to exacting dimensions, said Jud Ready, a GTRI senior research engineer and Walker's collaborator on the project. This project leverages our ability to grow well-aligned arrays of nanotubes and to coat them to enhance their field emission performance. In addition to reducing propellant consumption, use of carbon nanotube cathode arrays could improve reliability by replacing the single cathode now used in the thrusters. Existing cathodes are sensitive to contamination , damaged by the ionized exhaust of the thruster, and have limited life due to their high-temperature operation, Ready noted. The carbon nanotube cathode arrays would provide a distributed cathode around the Hall effect thruster so that if one of them is damaged, we will have redundancy. Before the carbon nanotube cathodes developed by Georgia Tech can be used on satellites, however, their lifetime will have to be increased to match that of a satellite thruster, which is typically 2,000 hours or more. The devices will also have to withstand the mechanical stresses of space launches, turn on and off rapidly, operate consistently and survive the aggressive space environment. Part of the effort will focus on special coating materials used to protect the carbon nanotubes from the space environment. For that part of the project, Walker and Ready are collaborating with Lisa Pfefferle in the Department of Chemical Engineering at Yale University. The researchers are testing their cathodes with the same Busek Hall effect thruster that flew on the U.S. Air Force's TacSat-2 satellite. In addition, the cathodes will be operated with Hall effect thrusters developed by Pratt and Whitney and donated to Georgia Tech. The researchers are also collaborating with L-3 ETI on the electrical power system and with American Pacific In-Space Propulsion on flight qualification of the hardware. The ability to control individual cathodes on the array could provide a new capability to vector the thrust, potentially replacing the mechanical gimbals now used. The use of carbon nanotubes to generate electrons through the field-effect process was reported in 1995 by a research team headed by Walt de Heer, a professor in Georgia Tech's School of Physics. Field emission is the extraction of electrons from a conductive material through quantum tunneling that occurs when an external electric field is applied. The improved carbon nanotube cathodes should advance the goals of reducing the cost of launching and maintaining satellites. Thrust with less propellant has been one of the major goals driving research into satellite propulsion, said Walker, who is director of Georgia Tech's High-Power Electric Propulsion Laboratory. Electric propulsion is becoming more popular and will benefit from our innovation. Ultimately, we will help improve the performance of in-space propulsion devices. 美国乔治亚技术研究院赢得了一份价值650万美元的合同，研发可以提高电推进系统效率的改良组件。这种电推进系统用于卫星和行星探测器的姿态控制。 研究工作将集中改进霍尔效应推进器装置的阴极，减少商业卫星、政府卫星和军事卫星的推进系统损耗，由此使卫星在轨停留更长时间，能使用更小、更经济的火箭发射，或者同样火箭可发射更大有效载荷。该项研究由美国国防预先研究计划局国防科学办公室（DARPA-DSO）发起，为期18个月，旨在验证霍尔效应推进器更少推进剂阴极的使用。 使用电推进系统的卫星进入太空后，有10%的推进剂势必要消耗在系统组成部分之一空心阴极上。利用场发射阴极取代空心阴极，可以无需浪费推进剂就拉动由碳纳米管产生的阴极列阵电子。由此可以通过更有效地使用有限的星载推进剂，而延长航天器寿命。除了减少推进剂消耗外，使用碳纳米管阴极阵列还可以改进使用单一阴极推进器的可靠性。该装置还必须承受太空发射时机械应力、快速启动与关闭、持续运行、以及在恶劣太空环境下的生存挑战。 为保持卫星在太空中的姿态和重新定位，必须使用化学或小型电推进器。电推力器采用电离惰性气体（如氙），产生的离子再从装置中喷射从而产生推力。 现有的霍尔效应推进器使用单一的高温阴极产生电子。对于携带有限燃料的卫星来说，有将近10%的推进剂被用作传统空心阴极的工作流体。DARPA出资的这项研究将使用大量由多层碳纳米管编制而成的场效应阴极阵列替换空心阴极。由星载电池和卫星光电系统供电，阵列将能以低功率运行，无需消耗推进剂就可产生电子。 此项工作在美国丹佛举行的2009美国航空航天学会（AIAA）联合推进大会上被展示过。额外的经费将支持改进碳纳米管冷阴极装置，以便在2015年进行太空试验。（中国航天工程咨询中心 陈菲 谢慧敏）
（ http://www.spacenews.com/civil/qinetiq-supply-ion-thrusters-for-bepicolombo.html ） Qinetiq to Supply Ion Thrusters for BepiColombo By Peter B. de Selding PARIS Europes BepiColombo satellite mission to Mercury will be propelled by new-generation ion-electric thrusters built by Qinetiq of Britain under a contract with BepiColombo prime contractor Astrium Satellites, Qinetiq announced Sept. 2. Under the contract, valued at 23 million British pounds ($37.4 million), Farnborough, England-based Qinetiq will provide four T6 ion thrusters for BepiColombo, which is being built for the European Space Agency (ESA) and scheduled for launch in 2014. The contract follows the successful in-orbit demonstration of Qinetiqs smaller T5 ion thrusters aboard ESAs GOCE gravity-field-measuring satellite, which was launched in March. ESA officials have said Qinetiqs ion thrusters, which had never before flown in space, have performed to specification. Qinetiq said its ion thrusters are 10 times more efficient than traditional chemical thrusters used on satellites. Qinetiq Chief Executive Graham Love said the BepiColombo work is the largest space-hardware contract ever won by the company. He said he hopes to sell the thrusters for future deep-space missions and in the commercial communications satellite market as well. （ http://news.mod.gov.cn/tech/2009-09/05/content_4084878.htm ） 欧空局（ESA）已经宣布，它最新的被称作BepiColombo的卫星将使用离子电推进器驶向水星，该离子推进器由英国奎蒂克（QinetiQ）公司开发。 欧空局已经在它的GOCE卫星上使用过一个更小型的同类系统由T5离子推进器组成。GOCE在09年早些时候发射，用来测量地球的重力场。BepiColombo计划在2014年发射，将使用4个T6离子推进器。奎蒂克公司称用于两个飞行器的推进器的效率比传统的化学推进器高十倍。欧空局授予奎蒂克公司价值3740万美元合同建造电推进系统。 尽管化学推进系统目前在太空被广泛使用，但是因为需要大量的燃料，它们对于像探测水星这样的深空任务来说不够高效。电推进系统产生的推进力较小，但是它们非常高效，因此对于远程飞行任务来说是理想的推进系统。 离子推进通过电子化或电离气体，并且加速由此产生的离子来推进航天器。此概念在50年前被首次提出，首个使用离子推进的航天器为1998年发射的深空1号（DS1）。从那时起，除了GOCE，仅有少量的其他非商业航天器使用过离子推进：NASA飞往太阳系之外的拂晓飞行任务在2007年发射；日本的深空小行星样本返回任务隼鸟在2003年发射；欧空局的SMART-1航天器在2003年发射并在2006年撞向月球。但使用离子推进器的商业通信卫星很多。NASA最近完成了一种新的离子推进系统的测试，这种系统将用于地球轨道和太阳系航天器，可能准备2013年发射。 虽然技术还需要一些微调，以便使这些发动机更加高效、紧凑和经济，但许多专家认为对于复杂的、需要更多能量的行星任务，离子电推进是肯定的选择。（中国航天工程咨询中心 谢慧敏）
http://www.spacechina.com/zxyzx_gjht_Details.shtml?recno=61482 美国Aerojet公司与日本NEC公司宣布，将联合探究低功率离子推进系统用于美日宇航市场的可行性。 由于具有更高的燃料效率，离子推进系统能够用作地球同步卫星的推进系统和深空任务。日本宇宙航空研发机构（JAXA）与NEC已联合研制了一台低功率微波离子发动机，它利用微波产生离子，具有寿命长和任务可靠性高的特征。 NEC的微波离子发动机目前正在执行JAXA的HAYABUSA小行星探测与研究任务。该任务已在太空运行超过30000小时，验证了离子发动机的坚固和可靠性。Aerojet的电子推进产品目前应用于150多颗运行卫星上。 （陈菲 曲佳） http://www.space-travel.com/reports/Aerojet_And_NEC_To_Develop_Ion_Propulsion_Systems_For_Satellites_999.html Aerojet And NEC To Develop Ion Propulsion Systems For Satellites Aerojet's electric propulsion products are currently flying on more than 150 operational satellites and span a broad range of electric propulsion products. by Staff Writers Sacramento CA (SPX) Aug 05, 2009 Aerojet and NEC Corporation have announced that the companies will jointly explore the feasibility of jointly supplying low power ion propulsion systems for the U.S. and Japanese aerospace markets. Ion propulsion systems can be used for geosynchronous satellite propulsion systems and deep space missions providing significant advantages over traditional chemical propulsion systems due to the higher fuel efficiency. Japan Aerospace Exploration Agency (JAXA) and NEC have jointly developed a low power Microwave Ion Engine that uses microwaves for ion generation, enabling long life and high mission reliability. NEC's Microwave Ion Engine is currently flying on JAXA's HAYABUSA asteroid rendezvous and study mission, and has proven to be robust and reliable, with more than 30,000 hours of in-space operation. Aerojet is a leading supplier of satellite propulsion systems in the United States and has broad experience and technical capabilities with satellite propulsion systems, said Kunio Kondo, senior general manager, Aerospace and Defense Operations Unit, NEC Corporation. Collaborating with Aerojet will help NEC to expand its low power Microwave Ion Engine business in the U. S. market. Aerojet's electric propulsion products are currently flying on more than 150 operational satellites and span a broad range of electric propulsion products. Dr. Roger Myers, general manager of Aerojet's Redmond operations, states that the low power Microwave Ion Engine from NEC provides an excellent complement to Aerojet's broad electric propulsion product offerings. 小知识：微波离子推进简介 离子推进又称为微波电子回旋共振离子推力器，是一种基于微波电子回旋共振放电技术的新式静电型离子推力器，该推力器具有无电极烧蚀、寿命长、比冲高、可靠性高等优点，适用于深空探测等长航时空间飞行任务。
The Call for Papers for the 41st Plasmadynamics and Lasers Conference is now open. Papers that describe basic and/or applied research in the areas of plasmadynamics, lasers, electromagnetics, diagnostics, and related topics in nonequilibrium reacting flows are now being solicited. Contributions on contemporary experimental, analytical, and computational methods with new results are strongly encouraged. The abstract deadline is 5 November 2009. 40th Fluid Dynamics Conference and Exhibit 10th AIAA/ASME Joint Thermophysics and Heat Transfer Conference 27th AIAA Aerodynamics Measurement and Ground Testing Conference 28th AIAA Applied Aerodynamics Conference 41st Plasmadynamics and Lasers Conference 5th Flow Control Conference 28 June - 1 July 2010 Hyatt Regency McCormick Place Chicago, Illinois To view a complete list submittable topic areas, or to submit your abstract please visit the conference Web site at, www.aiaa.org/events/Chicago2010 and click on submit a paper under the Plasmadynamics and Lasers Conference title.
标签: 电推进
