The Solar-Electric Sail: Application to Interstellar Migration and Consequences for SETI
The Solar-Electric Sail accelerates by reflecting positively charged solar wind ions. If it is used to propel an interstellar migration mission, its interstellar cruise velocity relative to the home star cannot exceed the solar wind velocity. In an effort to analytically determine interstellar cruis...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-04-01
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| Series: | Universe |
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| Online Access: | https://www.mdpi.com/2218-1997/8/5/252 |
| _version_ | 1797494949274451968 |
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| author | Gregory Lee Matloff |
| author_facet | Gregory Lee Matloff |
| author_sort | Gregory Lee Matloff |
| collection | DOAJ |
| description | The Solar-Electric Sail accelerates by reflecting positively charged solar wind ions. If it is used to propel an interstellar migration mission, its interstellar cruise velocity relative to the home star cannot exceed the solar wind velocity. In an effort to analytically determine interstellar cruise velocity for a 10<sup>7</sup> kg generation ship, a constant solar wind velocity within the heliosphere of a Sun-like star of 600 km/s is assumed. The solar wind proton density at 1 AU is also considered constant at 10 protons per cubic centimeter. Solar wind density is assumed to decrease with the inverse square of solar distance. It is shown that, to maintain sufficient acceleration to achieve an interstellar cruise velocity about 70% of the solar wind velocity, the radius of the sail’s electric field is enormous—greater than 10<sup>5</sup> km. Because the solar wind velocity and density are not constant, field strength must be varied rapidly to compensate for solar wind variation. Although not competitive with the ultimate theoretical performance of solar-photon sail propelled migrations departing from Sun-like stars, the solar-electric sail might be superior in this application for migration from dim K and M main sequence stars. Such migrations conducted during close stellar encounters might have durations < 1000 terrestrial years. If only a tiny fraction of M dwarf stars host star-faring civilizations, a significant fraction of Milky Way galaxy planetary systems may have been inhabited, even if no major advances over currently postulated interstellar transportation systems are postulated. SETI theoreticians should consider this when estimating the effects of interstellar colonization. |
| first_indexed | 2024-03-10T01:41:35Z |
| format | Article |
| id | doaj.art-a16802583cd14ac3a10cfa5bd03d3ad7 |
| institution | Directory Open Access Journal |
| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-03-10T01:41:35Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Universe |
| spelling | doaj.art-a16802583cd14ac3a10cfa5bd03d3ad72023-11-23T13:23:54ZengMDPI AGUniverse2218-19972022-04-018525210.3390/universe8050252The Solar-Electric Sail: Application to Interstellar Migration and Consequences for SETIGregory Lee Matloff0Physics Department, New York City College of Technology, City University of New York, 300 Jay St., Brooklyn, NY 11201, USAThe Solar-Electric Sail accelerates by reflecting positively charged solar wind ions. If it is used to propel an interstellar migration mission, its interstellar cruise velocity relative to the home star cannot exceed the solar wind velocity. In an effort to analytically determine interstellar cruise velocity for a 10<sup>7</sup> kg generation ship, a constant solar wind velocity within the heliosphere of a Sun-like star of 600 km/s is assumed. The solar wind proton density at 1 AU is also considered constant at 10 protons per cubic centimeter. Solar wind density is assumed to decrease with the inverse square of solar distance. It is shown that, to maintain sufficient acceleration to achieve an interstellar cruise velocity about 70% of the solar wind velocity, the radius of the sail’s electric field is enormous—greater than 10<sup>5</sup> km. Because the solar wind velocity and density are not constant, field strength must be varied rapidly to compensate for solar wind variation. Although not competitive with the ultimate theoretical performance of solar-photon sail propelled migrations departing from Sun-like stars, the solar-electric sail might be superior in this application for migration from dim K and M main sequence stars. Such migrations conducted during close stellar encounters might have durations < 1000 terrestrial years. If only a tiny fraction of M dwarf stars host star-faring civilizations, a significant fraction of Milky Way galaxy planetary systems may have been inhabited, even if no major advances over currently postulated interstellar transportation systems are postulated. SETI theoreticians should consider this when estimating the effects of interstellar colonization.https://www.mdpi.com/2218-1997/8/5/252electric sailinterstellar migrationred dwarf starsSETI |
| spellingShingle | Gregory Lee Matloff The Solar-Electric Sail: Application to Interstellar Migration and Consequences for SETI Universe electric sail interstellar migration red dwarf stars SETI |
| title | The Solar-Electric Sail: Application to Interstellar Migration and Consequences for SETI |
| title_full | The Solar-Electric Sail: Application to Interstellar Migration and Consequences for SETI |
| title_fullStr | The Solar-Electric Sail: Application to Interstellar Migration and Consequences for SETI |
| title_full_unstemmed | The Solar-Electric Sail: Application to Interstellar Migration and Consequences for SETI |
| title_short | The Solar-Electric Sail: Application to Interstellar Migration and Consequences for SETI |
| title_sort | solar electric sail application to interstellar migration and consequences for seti |
| topic | electric sail interstellar migration red dwarf stars SETI |
| url | https://www.mdpi.com/2218-1997/8/5/252 |
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