Very large floating structure: Difference between revisions

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Revision as of 03:41, 30 December 2020

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A ''Mega-Float'' [[floating airport]] prototype was constructed in Tokyo Bay from 1998 to 1999.<ref>[http://www.build.new-atlantis.org/vlfs.htm Very large floating structure — Mega-Float, completed 1999]. New Atlantis 2002, retrieved 1 October 2011</ref> It was one kilometer in length, and was primarily intended as a test vehicle, to research the loadings and responses of such installations.<ref>Areas being studied in Mega-Float include the hydroelastic behavior of the unit, the mooring system response and durability, the connector system and its welded joints, the anti-corrosion system, the unit's effect on the surrounding seawaves which impact the nearby shoreline, and the unit's effect on the bay's prevailing currents, water quality and marine ecosystems.</ref> This project was substituted as a study project to provide more definite information about a proposed floating runway at [[Kansai International Airport]], which was not built (an artificial island was instead constructed to support the runway).

=== Floating landinglaunch vehicle operations platform platforms===

In the 2010s, [[SpaceX]] contracted with a [[Louisiana]] [[shipyard]] to build a [[floating landing platform]] for [[reusable launch system|reusable]] [[orbital spaceflight|orbital]] [[launch vehicle]]s. The platform had an approximately {{convert|90|x|50|m|sp=us}} landing pad surface and was capable of precision [[Dynamic positioning|positioning]] with [[Diesel engine|diesel-powered]] [[azimuth thruster]]s<ref name=tm20141122>{{cite web|title=SpaceX Announces Spaceport Barge Positioned by Thrustmaster's Thrusters|url=http://www.thrustmaster.net/spacex-announces-spaceport-barge-positioned-thrustmasters-thrusters/|publisher=Thrustmaster|accessdate=23 November 2014|date=22 November 2014|url-status=dead|archiveurl=https://web.archive.org/web/20141207091326/http://www.thrustmaster.net/out-drive-propulsion-unit/portable-dynamic-positioning-system/|archivedate=7 December 2014|df=dmy-all}}</ref> so the platform can hold its position for launch vehicle landing. This platform was first deployed in January 2015<ref name=nsf20141217>{{cite news|last1=Bergin|first1=Chris|title=SpaceX confirms CRS-5 launch slip to 6 January|url=http://www.nasaspaceflight.com/2014/12/spacex-static-fire-falcon-9-crs-5/|accessdate=18 December 2014|work=NASASpaceFlight.com|date=17 December 2014}}</ref> when SpaceX attempted a [[Falcon 9 ocean booster landing tests|controlled descent]] [[flight test]] to land the first stage of [[Falcon 9 Flight 14]] on a solid surface after it was used to loft a contracted payload toward Earth orbit.<ref name=sn20141024>{{cite news|last1=Foust|first1=Jeff|title=Next Falcon 9 Launch Could See First-stage Platform Landing|url=http://www.spacenews.com/article/launch-report/42305next-falcon-9-launch-could-see-first-stage-platform-landing|accessdate=25 October 2014|work=Space News|date=25 October 2014}}</ref><ref name=tr20141026>{{cite news|last1=Bullis|first1=Kevin|title=SpaceX Plans to Start Reusing Rockets Next Year|url=http://www.technologyreview.com/news/532066/spacex-plans-to-start-reusing-rockets-next-year/|accessdate=26 October 2014|work=MIT Technology Review|date=25 October 2014}}</ref> The platform utilizes [[Global Positioning System|GPS]] [[Differential GPS|position information]] to navigate and hold its precise position.<ref name=ft20141024>{{cite news|last1=Dean|first1=James|title=SpaceX to attempt Falcon 9 booster landing on floating platform|url=http://www.floridatoday.com/story/tech/science/space/spacex/2014/10/24/spacex-attempt-falcon-booster-landing-floating-platform/17847817/|accessdate=27 October 2014|date=24 October 2014}}</ref> The rocket [[launch vehicle landing gear|landing leg]] span is {{convert|60|ft|m|disp=flip|abbr=on}} and must not only land within the {{convert|170|ft|m|disp=flip|abbr=on|adj=on}}-wide barge deck, but must also deal with [[Swell (ocean)|ocean swells]] and [[Dilution of precision (GPS)|GPS errors]].

SpaceX CEO [[Elon Musk]] first displayed a photograph of the "[[autonomous spaceport drone ship]]" in November 2014. The ship is designed to hold position to within {{convert|3|m|sp=us}}, even under storm conditions.<ref name=musk20141122>{{cite web|last1=Musk|first1=Elon|title=Autonomous spaceport drone ship|url=https://twitter.com/elonmusk/status/536262624653365248|publisher=SpaceX|accessdate=23 November 2014|date=22 November 2014}}</ref>