{"id":10205,"date":"2015-03-21T16:04:22","date_gmt":"2015-03-21T20:04:22","guid":{"rendered":"http:\/\/hobbyspace.com\/Blog\/?p=10205"},"modified":"2021-10-05T00:20:39","modified_gmt":"2021-10-05T04:20:39","slug":"estimating-the-safety-of-moon-tunnels-the-in-space-colony-concept","status":"publish","type":"post","link":"https:\/\/hobbyspace.com\/Blog\/?p=10205","title":{"rendered":"Estimating the safety of Moon tunnels + The in-space colony concept"},"content":{"rendered":"<p>A group at Purdue University has released an interesting study of <a href=\"http:\/\/en.wikipedia.org\/wiki\/Lunar_lava_tube\" target=\"_blank\" rel=\"noopener\">lava tubes on the Moon<\/a> in which they examined the\u00a0possibility that\u00a0there are ones big enough and stable enough to hold cities:<\/p>\n<ul>\n<li><a href=\"http:\/\/www.purdue.edu\/newsroom\/releases\/2015\/Q1\/theoretical-study-suggests-huge-lava-tubes-could-exist-on-moon.html\" target=\"_d\" rel=\"noopener\">Theoretical study suggests huge lava tubes could exist on moon Purdue News<\/a><\/li>\n<li><a href=\"http:\/\/www.leonarddavid.com\/tunnel-vision-underground-cities-on-the-moon\/\" target=\"_d\" rel=\"noopener\">Tunnel Vision: Underground Cities on the Moon &#8211; Leonard David<\/a><\/li>\n<\/ul>\n<p><a href=\"http:\/\/hobbyspace.com\/Blog\/wp-content\/uploads\/2015\/03\/moon-blair-lavatubes-purdue1.jpg\"><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"10206\" data-permalink=\"https:\/\/hobbyspace.com\/Blog\/?attachment_id=10206\" data-orig-file=\"https:\/\/hobbyspace.com\/Blog\/wp-content\/uploads\/2015\/03\/moon-blair-lavatubes-purdue1.jpg\" data-orig-size=\"3175,800\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;The city of Philadelphia is shown inside a theoretical lunar lava tube. A Purdue University team of researchers explored whether lava tubes more than 1 kilometer wide could remain structurally stable on the moon. (Purdue University\/courtesy of David Blair)&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;1&quot;}\" data-image-title=\"moon-blair-lavatubes-purdue[1]\" data-image-description=\"&lt;p&gt;The city of Philadelphia is shown inside a theoretical lunar lava tube. A Purdue University team of researchers explored whether lava tubes more than 1 kilometer wide could remain structurally stable on the moon. (Purdue University\/courtesy of David Blair)&lt;\/p&gt;\n\" data-image-caption=\"\" data-large-file=\"https:\/\/hobbyspace.com\/Blog\/wp-content\/uploads\/2015\/03\/moon-blair-lavatubes-purdue1-1024x258.jpg\" class=\"aligncenter size-large wp-image-10206\" src=\"http:\/\/hobbyspace.com\/Blog\/wp-content\/uploads\/2015\/03\/moon-blair-lavatubes-purdue1-1024x258.jpg\" alt=\"moon-blair-lavatubes-purdue[1]\" width=\"520\" height=\"131\" srcset=\"https:\/\/hobbyspace.com\/Blog\/wp-content\/uploads\/2015\/03\/moon-blair-lavatubes-purdue1-1024x258.jpg 1024w, https:\/\/hobbyspace.com\/Blog\/wp-content\/uploads\/2015\/03\/moon-blair-lavatubes-purdue1-300x76.jpg 300w\" sizes=\"auto, (max-width: 520px) 100vw, 520px\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><em>This diagram illustrates a lava tube protecting\u00a0a city the size<\/em><br \/>\n<em>of Philadelphia.\u00a0Purdue University\/courtesy of David Blair<\/em><\/p>\n<p>Lava tubes are<\/p>\n<p style=\"padding-left: 30px;\"><em>tunnels formed from the lava flow of volcanic eruptions. The edges of the lava cool as it flows to form a pipe-like crust around the flowing river of lava. When the eruption ends and the lava flow stops, the pipe drains leave behind a hollow tunnel, said Jay Melosh, a Purdue University distinguished professor of earth, atmospheric and planetary sciences who is involved in the research.<\/em><\/p>\n<p>There is indirect evidence that\u00a0lava tubes exist on the Moon. A number of <a href=\"http:\/\/the-moon.wikispaces.com\/Skylights\" target=\"_blank\" rel=\"noopener\">large holes<\/a>, for example, have been seen on the Moon and it is speculated that these could be where the roofs of lava tubes have collapsed. See\u00a0<a href=\"http:\/\/www.lpi.usra.edu\/decadal\/leag\/AndrewWDagaFINAL.pdf\" target=\"_d\" rel=\"noopener\">Lunar and Martian Lava Tube: Exploration\u00a0as Part of an Overall Scientific Survey, Daga et al. (pdf)<\/a>.<\/p>\n<p>The Purdue study considered the case of really large tubes:<\/p>\n<p class=\"FORMAT-BODY\" style=\"padding-left: 30px;\"><em>David Blair, a graduate student in Purdue&#8217;s <a href=\"http:\/\/www.eaps.purdue.edu\/\">Department of Earth, Atmospheric and Planetary Sciences<\/a>, led the study that examined whether empty lava tubes more than 1 kilometer wide could remain structurally stable on the moon.<\/em><\/p>\n<p class=\"FORMAT-BODY\" style=\"padding-left: 30px;\"><em>&#8220;We found that if lunar lava tubes existed with a strong arched shape like those on Earth, they would be stable at sizes up to 5,000 meters, or several miles wide, on the moon,&#8221; Blair said. &#8220;This wouldn&#8217;t be possible on Earth, but gravity is much lower on the moon and lunar rock doesn&#8217;t have to withstand the same weathering and erosion. In theory, huge lava tubes &#8211; big enough to easily house a city &#8211; could be structurally sound on the moon.&#8221;<\/em><\/p>\n<p class=\"FORMAT-BODY\" style=\"padding-left: 30px;\"><em>Blair worked with Antonio Bobet, a Purdue professor of civil engineering, and applied known information about lunar rock and the moon&#8217;s environment to civil engineering technology used to design tunnels on Earth.<\/em><\/p>\n<p class=\"FORMAT-BODY\" style=\"padding-left: 30px;\"><em>The team found that a lava tube&#8217;s stability depended on the width, roof thickness and the stress state of the cooled lava, and the team modeled a range of these variables. The researchers also modeled lava tubes with walls created by lava placed in one thick layer and with lava placed in many thin layers, Blair said.<\/em><\/p>\n<p>&#8212;<\/p>\n<p>Personally, rather than on the Moon I would prefer to live in a large, island-sized, <a href=\"http:\/\/en.wikipedia.org\/wiki\/O%27Neill_cylinder\" target=\"_blank\" rel=\"noopener\">in-space habitat<\/a> like that promoted by the late Princeton physics professor <a href=\"http:\/\/ssi.org\/the-life-of-gerard-k-oneill\/\" target=\"_blank\" rel=\"noopener\">Gerard K. O&#8217;Neill<\/a>\u00a0. Rotation could provide a full 1 g of spin-gravity, no lunar dust to hassle with and breath, sunlight all around, and there would be a greater sense of freedom of movement. That is, why work so hard to get out of earth&#8217;s gravity well just to\u00a0jump down another one?<\/p>\n<p>Every so often, someone on the web discovers the great space colony artwork from <a href=\"http:\/\/ssi.org\/space-art\/ssi-sample-slides\/\" target=\"_blank\" rel=\"noopener\">the workshops<\/a>\u00a0that studied such structures:\u00a0<a href=\"http:\/\/mashable.com\/2015\/03\/21\/space-colony-design\/\" target=\"_blank\" rel=\"noopener\">How we&#8217;ll live in space, according to people in the 1970s &#8211; mashable<\/a><\/p>\n<p style=\"text-align: center;\">[]<br \/>\n<em>Interior including human powered flight. Art work: Rick Guidice.<\/em><br \/>\n<em>Image via NASA Ames Research Center.<\/em><\/p>\n<p class=\"credit\">At the time, such ambitions were believed justified by the big drop in space transportation costs that would come when the Space Shuttle began to fly. The Moon would still be useful &#8211; as a source of\u00a0the materials to build such huge structures.\u00a0It&#8217;s low gravity would allow building materials literally to be thrown into space by <a href=\"http:\/\/en.wikipedia.org\/wiki\/Mass_driver\" target=\"_blank\" rel=\"noopener\">mass drivers<\/a>, i.e. electromagnetic catapults.<\/p>\n<p class=\"credit\">Unfortunately, the hyper-complex and fragile Shuttles failed to lower space transport costs at all. The original fully reusable design for the Shuttles was down-graded by budget cuts and the Shuttles became only partially refurbish-able, requiring a standing army of thousands to work for months to return one to flight.<\/p>\n<p class=\"credit\">Today we finally are seeing\u00a0<a href=\"http:\/\/en.wikipedia.org\/wiki\/SpaceX_reusable_launch_system_development_program\" target=\"_blank\" rel=\"noopener\">new approaches<\/a> to reusable space vehicles that intend\u00a0to achieve\u00a0full reusability and fast turnaround. We could see the cost of getting to\u00a0space drop by factors of 100 in the coming decade.<\/p>\n<p class=\"credit\">Low cost spaceflight combined with new technologies like 3D printing and advanced robotics will make it affordable to build\u00a0large scale structures in space.\u00a0\u00a0Today&#8217;s space pessimism towards concepts like in-space colonies will give way to taking them granted just as we take granted the <a href=\"http:\/\/www.burjkhalifa.ae\/en\/\" target=\"_blank\" rel=\"noopener\">giant structures<\/a> on earth that once would have been considered fantasies.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A group at Purdue University has released an interesting study of lava tubes on the Moon in which they examined the\u00a0possibility that\u00a0there are ones big enough and stable enough to hold cities: Theoretical study suggests huge lava tubes could exist on moon Purdue News Tunnel Vision: Underground Cities on the Moon &#8211; Leonard David This &hellip; <a href=\"https:\/\/hobbyspace.com\/Blog\/?p=10205\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Estimating the safety of Moon tunnels + The in-space colony concept<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[17,18,24],"tags":[],"class_list":["post-10205","post","type-post","status-publish","format-standard","hentry","category-living-in-space","category-space-settlement","category-the-moon"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p34aWK-2EB","jetpack-related-posts":[{"id":19382,"url":"https:\/\/hobbyspace.com\/Blog\/?p=19382","url_meta":{"origin":10205,"position":0},"title":"Space settlement roundup &#8211; Aug.3.2019","author":"TopSpacer","date":"August 3, 2019","format":false,"excerpt":"A sampling of recent articles, videos, and images related to human expansion into the solar system: ** Purdue University unveils Cislunar Space Engineering Initiatives program: Vision Statement The Purdue Engineering Initiative in Cislunar Space (Cislunar Initiative) will envision and enable the collaborative utilization of cislunar space to extend humanity\u2019s reach\u2026","rel":"","context":"In &quot;In Space Infrastructure&quot;","block_context":{"text":"In Space Infrastructure","link":"https:\/\/hobbyspace.com\/Blog\/?cat=15"},"img":{"alt_text":"Next Generation Space Suit","src":"https:\/\/i0.wp.com\/hobbyspace.com\/Blog\/wp-content\/uploads\/2019\/08\/spacesuit1-1024x576.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":18771,"url":"https:\/\/hobbyspace.com\/Blog\/?p=18771","url_meta":{"origin":10205,"position":1},"title":"Space settlement roundup &#8211; May.16.2019","author":"TopSpacer","date":"May 16, 2019","format":false,"excerpt":"A sampling of recent articles, videos, and images related to human settlements in the solar system: ** Jeff Bezos plans to develop technologies that will enable the building of enormous in-space habitats according to his statements in last week's presentation, which included the unveiling of the Blue Moon lunar lander.\u2026","rel":"","context":"In &quot;In Space Infrastructure&quot;","block_context":{"text":"In Space Infrastructure","link":"https:\/\/hobbyspace.com\/Blog\/?cat=15"},"img":{"alt_text":"Large Habitat - Blue Origin ","src":"https:\/\/i0.wp.com\/hobbyspace.com\/Blog\/wp-content\/uploads\/2019\/05\/LargeHabitat_BlueOrigin-1600x901-1024x577.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":7418,"url":"https:\/\/hobbyspace.com\/Blog\/?p=7418","url_meta":{"origin":10205,"position":2},"title":"A TEDx talk about a Mars research station + Purdue students plan a Moon colony","author":"TopSpacer","date":"April 18, 2014","format":false,"excerpt":"In a TEDx talk, Shaun Moss lays out his vision of settling Mars in an affordable way. 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