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Carbon nanotube sheets for solar sails for 5.6% of lightspeed
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Multiwall carbon nanotube sheets have been made with a mass of ~27 milligrams per square metre and about the strength of kevlar. Adam Crowl of Crowlspace examines this a bit more. Nextbigfuture covered the dry spinning of carbon nanotubes into sheets back in 2007.
The self-supporting MWNT sheets initially form as a highly anisotropic aerogel that can be densfied into strong sheets that are as thin as 50 nm. The areal density of the sheet is 30 mg/m and there is no fundamental limit on
sheet width or length. The measured gravimetric strength of orthogonally oriented sheet arrays exceeds that of the highest strength steel sheet.
In theory that means a suitably steered solar-sail made of CNT sheet could send itself away from Earth’s orbit and reach a final speed of 42*sqrt(57-1) km/s ~ 315 km/s. If it swooped past Jupiter then swung in hard for the Sun, scooting past at 0.019 AU, then it would recede at ~2,200 km/s (0.73 % of lightspeed).
Atomic layer deposition for solar sails almost as good as carbon nanotubes
The material developed for the proposed Drexler solar sail was a thin aluminum film with a baseline thickness of 0.1 micrometres (100 nanometers), to be fabricated by vapor deposition in a space-based system. Drexler used a similar process to prepare films on the ground. As anticipated, these films demonstrated adequate strength and robustness for handling in the laboratory and for use in space, but not for folding, launch, and deployment. Vapor deposition aluminum at 100 nanometer thickness would mass less than 0.1 grams/meter.
See more and subscribe to NextBigFuture at 2013-02-13 02:00:16 Source: http://nextbigfuture.com/2013/02/carbon-nanotube-sheets-for-solar-sails.html
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