Editing Magnetic sail (section)

== History of concept ==
An overview of many of the magnetic sail proposed designs with illustrations from the references was published in 2018 by Djojodihardjo.<ref name=":0" /> The earliest method proposed by Andrews and Zubrin in 1988,<ref name=":6">D. G. Andrews and R. Zubrin, "Magnetic Sails and Interstellar Travel", Paper IAF-88-553, 1988</ref> dubbed the [[#Magsail (MS)|magsail]], has the significant advantage of requiring no propellant and is thus a form of [[Field propulsion#Practical methods|field propulsion]] that can operate indefinitely. A drawback of the magsail design was that it required a large (50–100&nbsp;km radius) superconducting loop carrying large currents with a mass on the order of {{Convert|100|tonnes|kg}}. The magsail design also described [[#Modes of operation|modes of operation]] for interplanetary transfers,<ref name=":13">{{Cite journal |last1=Zubrin |first1=Robert M. |last2=Andrews |first2=Dana G. |date=July 1989 |title=Magnetic sails and interplanetary travel |url=https://www.researchgate.net/publication/236447908 |journal=Journal of Spacecraft and Rockets |language=en |volume=28 |issue=2 |pages=197–203 |doi=10.2514/3.26230 |issn=0022-4650}}</ref> thrusting against a planetary [[ionosphere]] or [[magnetosphere]],<ref name=":13" /> escape from low Earth orbit<ref name=":5" /> as well as deceleration of an interstellar craft over decades after being initially accelerated by other means, for example. a [[fusion rocket]], to a significant fraction of light speed,<ref name=":6" /> with a more detailed design published in 2000.<ref name=":1">{{Cite web |last1=Zubrin |first1=R. |last2=Martin |first2=A. |date=January 7, 2000 |title=The Magnetic Sail -Final Report to the NASA Institute of Advanced Concepts (NIAC) |url=http://www.niac.usra.edu/files/studies/final_report/320Zubrin.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.niac.usra.edu/files/studies/final_report/320Zubrin.pdf |archive-date=2022-10-09 |access-date=June 13, 2022 |website=www.niac.usra.edu}}</ref> In 2015, Freeland<ref name=":14">{{Cite journal |last=Freeland |first=R.M. |date=2015 |title=Mathematics of Magsail |url=https://bis-space.com/shop/product/mathematics-of-magsails/ |journal=Journal of the British Interplanetary Society |volume=68 |pages=306–323 |via=bis-space.com}}</ref> validated most of the initial magsail analysis, but determined that thrust predictions were optimistic by a factor of 3.1 due to a numerical integration error.

Subsequent designs proposed and analyzed means to significantly reduce mass. These designs require little to modest amounts of exhausted propellant and can thrust for years. All proposed designs describe thrust from solar wind outwards from the Sun.  In 2000, Winglee and Slough proposed a [[#Mini-magnetospheric plasma propulsion (M2P2)|Mini-Magnetospheric Plasma Propulsion (M2P2)]] design that injected low energy plasma into a much smaller coil with much lower mass that required low power.<ref name=":2">{{Cite journal |last1=Winglee |first1=R.M. |last2=Slough |first2=J. |last3=Ziemba |first3=T. |date=September 2000 |title=Mini-Magnetospheric Plasma Propulsion: Tapping the energy of the solar wind for spacecraft propulsion |url=https://www.researchgate.net/publication/248799668 |journal=Journal of Geophysical Research: Atmospheres |volume=105 |issue=A9 |pages=21067–21078 |bibcode=2000JGR...10521067W |doi=10.1029/1999JA000334}}</ref> Simulations predicted impressive performance relative to mass and required power; however, a number of critiques raised issues: that the assumed magnetic field falloff rate was optimistic and that thrust was dramatically overestimated.

Starting in 2003, Funaki and others published a series of theoretical, simulation and experimental investigations at JAXA in collaboration with Japanese universities addressing some of the issues from criticisms of M2P2 and named their approach the [[#Magnetoplasma sail (MPS)|MagnetoPlasma Sail (MPS)]].<ref name=":30" /> In 2011, Funaki and Yamakawa authored a chapter in a book that is a good reference for magnetic sail theory and concepts.<ref name=":3" /> MPS research resulted in many published papers that advanced the understanding of [[#Physical principles|physical principles for magnetic sails]]. Best performance occurred when the injected plasma had a lower density and velocity than considered in M2P2. Thrust gain was computed as compared with performance with a magnetic field only in 2013<ref name=":222">{{Cite journal |last1=Funaki |first1=Ikkoh |last2=Kajimura |first2=Yoshihiro |last3=Ashida |first3=Yasumasa |last4=Yamakawa |first4=Hiroshi |last5=Nishida |first5=Hiroyuki |last6=Oshio |first6=Yuya |last7=Ueno |first7=Kazuma |last8=Shinohara |first8=Iku |last9=Yamamura |first9=Haruhito |last10=Yamagiwa |first10=Yoshiki |date=2013-07-14 |title=Magnetoplasma Sail with Equatorial Ring-current |url=https://arc.aiaa.org/doi/10.2514/6.2013-3878 |journal=49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference |series=Joint Propulsion Conferences |language=en |location=San Jose, CA |publisher=American Institute of Aeronautics and Astronautics |doi=10.2514/6.2013-3878 |isbn=978-1-62410-222-6}}</ref> and 2014.<ref>{{Cite journal |last1=Kajimura |first1=Yoshihiro |last2=Funaki |first2=Ikkoh |last3=Shinohara |first3=Iku |last4=Usui |first4=Hideyuki |last5=Matsumoto |first5=Masaharu |last6=Yamakawa |first6=Hiroshi |date=2014 |title=Numerical Simulation of Dipolar Magnetic Field Inflation due to Equatorial Ring-Current |url=https://www.jstage.jst.go.jp/article/pfr/9/0/9_2405008/_article |journal=Plasma and Fusion Research |volume=9 |pages=2405008 |bibcode=2014PFR.....905008K |doi=10.1585/pfr.9.2405008|doi-access=free }}</ref> Investigations and experiments continued reporting increased thrust experimentally and numerically considering use of a [[Magnetoplasmadynamic thruster]] (aka MPD Arc jet in Japan)in 2015,<ref name=":162">{{Cite web |last1=Hagiwara |first1=T. |last2=Kajimura |first2=Y. |last3=Oshio |first3=Y. |last4=Funaki |first4=I. |date=July 4–10, 2015 |title=Thrust Measurement of Magneto Plasma Sail with Magnetic Nozzle by Using Thermal Plasma Injection |url=http://electricrocket.org/IEPC/IEPC-2015-461p_ISTS-2015-b-461p.pdf |access-date=June 13, 2022 |website=}}</ref>  multiple antenna coils in 2019,<ref>{{Cite journal |last1=Murayama |first1=Yuki |last2=Ueno |first2=Kazuma |last3=Oshio |first3=Yuya |last4=Horisawa |first4=Hideyuki |last5=Funaki |first5=Ikkoh |date=2019-09-01 |title=Preliminary results of magnetic field measurements on multi-coil magnetic sail in laboratory experiment |url=https://www.sciencedirect.com/science/article/pii/S0042207X17315075 |journal=Vacuum |language=en |volume=167 |pages=509–513 |bibcode=2019Vacuu.167..509M |doi=10.1016/j.vacuum.2018.05.004 |issn=0042-207X |s2cid=103150548}}</ref> and a multi-pole MPD thruster in 2020.<ref name="Murayama">{{Citation |last1=Murayama |first1=Yuki |title=Relationship of Current Distribution of Magnetopause and Thrust Characteristics in Multipole Magnetic Sail |date=2020-08-17 |url=https://arc.aiaa.org/doi/10.2514/6.2020-3634 |work=AIAA Propulsion and Energy 2020 Forum |access-date=2022-07-15 |series=AIAA Propulsion and Energy Forum |publisher=American Institute of Aeronautics and Astronautics |doi=10.2514/6.2020-3634 |isbn=978-1-62410-602-6 |s2cid=225207397 |last2=Ueno |first2=Kazuma |last3=Oshio |first3=Yuya |last4=Horisawa |first4=Hideyuki |last5=Funaki |first5=Ikkoh}}</ref>

Slough published in 2004<ref name=":18">{{Cite web |last=Slough |first=John |date=March 2004 |title=The Plasma Magnet Phase I Final Report |url=http://www.niac.usra.edu/files/studies/final_report/860Slough.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.niac.usra.edu/files/studies/final_report/860Slough.pdf |archive-date=2022-10-09 |access-date=June 14, 2022 |website=www.niac.usra.edu}}</ref> and 2006<ref name="Slough2006">{{cite web |last1=Slough |first1=John |date=September 30, 2006 |title=The Plasma Magnet – Phase II Final Report |url=http://www.niac.usra.edu/files/studies/final_report/917Slough.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.niac.usra.edu/files/studies/final_report/917Slough.pdf |archive-date=2022-10-09 |access-date=13 June 2022 |website=NASA Institute for Advanced Concepts |publisher=NASA}}</ref>  a method to generate the static magnetic dipole for a magnetic sail in a design called the [[#Plasma magnet (PM)|Plasma magnet (PM)]] that was described as an [[Induction motor#3-phase motor|AC induction motor]] turned inside out. A pair of small perpendicularly oriented coils acted as the stator powered by an alternating current to generate a [[Rotating magnetic field|rotating magnetic field (RMF)]] that analysis predicted and laboratory experiments demonstrated that a current disc formed as the rotor outside the stator.  The current disk formed from electrons captured from the plasma wind, therefore requiring little to no plasma injection. Predictions of substantial improvements in terms of reduced coil size (and hence mass) and markedly lower power requirements for significant thrust hypothesized the same optimistic magnetic field falloff rate as assumed for M2P2. In 2022, a spaceflight trial dubbed Jupiter Observing Velocity Experiment (JOVE) proposed using a [[plasma magnet]] based sail for a spacecraft named Wind Rider using the solar wind to accelerate away from a point near Earth and decelerate against the [[magnetosphere of Jupiter]].<ref name=":11">{{Cite journal |last1=Freeze |first1=Brent |last2=Greason |first2=Jeff |last3=Nader |first3=Ronnie |last4=Febres |first4=Jaime Jaramillo |last5=Chaves-Jiminez |first5=Adolfo |last6=Lamontagne |first6=Michel |last7=Thomas |first7=Stephanie |last8=Cassibry |first8=Jason |last9=Fuller |first9=John |last10=Davis |first10=Eric |last11=Conway |first11=Darrel |date=2022-02-01 |title=Jupiter Observing Velocity Experiment (JOVE): Introduction to Wind Rider Solar Electric Propulsion Demonstrator and Science Objectives |journal=Publications of the Astronomical Society of the Pacific |volume=134 |issue=1032 |pages=023001 |bibcode=2022PASP..134b3001F |doi=10.1088/1538-3873/ac4812 |issn=0004-6280 |s2cid=247088246|doi-access=free }}</ref>

A 2012, study by Kirtley and Slough investigated using the plasma magnet technology to use plasma in a planetary ionosphere as a braking mechanism and was called the Plasma Magnetoshell.<ref name=":7">{{Cite report |url=https://www.nasa.gov/sites/default/files/atoms/files/niac_2012_phasei_kirtley_plasmaaerocapture_tagged.pdf |title=A Plasma Aerocapture and Entry System for Manned Missions and Planetary Deep Space Orbiters – Phase I Final Report |last1=Kirtley |first1=David |last2=Slough |first2=John |date=2012 |doi=10.2514/6.2014-1230 |access-date=June 14, 2022 |archive-url=https://ghostarchive.org/archive/20221009/https://www.nasa.gov/sites/default/files/atoms/files/niac_2012_phasei_kirtley_plasmaaerocapture_tagged.pdf |archive-date=2022-10-09 |website=www.nasa.gov/sites/default/files/atoms/files/ |hdl=2060/20190002578 |s2cid=67801776}}</ref> This paper restated the magnetic field falloff rate to the value suggested in the critiques of M2P2 that dramatically reduces analytical predicted performance. Initial missions targeted deceleration in the ionosphere of Mars. Kelly and Little in 2019<ref name=":35" /> published simulation results using a multi-turn coil and not the plasma magnet showed that the magnetoshell was viable for orbital insertion asy Mars, Jupiter, Neptune and Uranus and in 2021<ref name=":36" /> showed that it was more efficient than [[aerocapture]] for Neptune.

In 2021, Zhenyu Yang and others published an analysis, numerical calculations and experimental verification for a propulsion system that was a combination of the magnetic sail and the [[electric sail]] called an electromagnetic sail.<ref name=":19">{{Cite journal |last1=Yang |first1=Zhenyu |last2=Zhang |first2=Zhihao |last3=Fan |first3=Wei |last4=Deng |first4=Yongfeng |last5=Han |first5=Xianwei |date=2021-05-01 |title=Mechanism analysis and experimental verification of electromagnetic sail, a new solar propulsion system without propellent |url=https://aip.scitation.org/doi/10.1063/5.0045258 |journal=AIP Advances |language=en |volume=11 |issue=5 |pages=055222 |bibcode=2021AIPA...11e5222Y |doi=10.1063/5.0045258 |issn=2158-3226 |s2cid=236358275}}</ref> A superconducting magsail coil augmented by an [[electron gun]] at the coil's center generates an electric field as in an electric sail that deflects positive ions in the plasma wind thereby providing additional thrust, which could reduce overall system mass.