Recent research from the National Oceanic and Atmospheric Administration<\/a> (NOAA) found that 10% of atmospheric aerosol in the stratosphere contained metallic particles from spacecraft, including satellites. The long-term impact of these metal fragments is unknown, but scientists are concerned it could damage Earth\u2019s fragile ozone layer.<\/a><\/p>\n\n\n\n Wooden satellites would be better for the planet while still providing the same functionality as their metal counterparts, says Murata.<\/p>\n\n\n\n \u201cAt the end of their life, satellites re-enter the atmosphere. The difference is, the wood in the LignoSat will burn up and eventually become a gas, whereas metals become fine particles instead,\u201d says Murata.<\/p>\n\n\n\n It\u2019s not just a pipedream: Murata and his team have been working on the project for four years and sent wood samples to space in 2021 to test the material\u2019s resilience to space conditions.<\/p>\n\n\n\n Now, they are <\/strong>working with Japan\u2019s space agency (JAXA) and NASA to send the prototype satellite, called LignoSat, into orbit early next year.<\/p>\n\n\n\n For Murata, who is head of the space-wood project at Kyoto University, wood is an obvious choice for space structures.<\/p>\n\n\n\n \u201cWhen you use wood on Earth, you have the problems of burning, rotting, and deformation, but in space, you don\u2019t have those problems: there is no oxygen in space, so it doesn\u2019t burn, and no living creatures live in them, so they don\u2019t rot,\u201d he says.<\/p>\n\n\n The strength per weight of wood is the same as aluminum which also makes it a compelling choice for space construction, Murata adds \u2014 and the team\u2019s tests conducted at the International Space Station found that wood is remarkably resilient in outer space.<\/p>\n\n\n\n For the satellite, Murata tested three wood types: Erman\u2019s birch \u2014 which is <\/strong>commonly found in East Asia \u2014 Japanese cherry and magnolia obovata \u2014 a species native to Japan. While cypress and cedar would be more common wood types for construction, the team \u201cchose materials that could withstand as much detailed work as possible,\u201d because of the small size of the satellites, says Murata.<\/p>\n\n\n\n Ultimately, the magnolia wood won, as its cells are small and uniform in size, which makes the wood easier to work with and less likely to split or break, he <\/strong>says.<\/p>\n\n\n\n Humans have been putting satellites into orbit since the 1950s, with up to 100 spacecraft launched every year until 2010. But over the past decade, commercial launches have become more accessible and this number has increased dramatically<\/a>, surpassing 1,400 new satellites <\/strong>in 2021<\/a>. With the number of rockets sent to space likely to increase, the NOAA research projected that in the coming decades, as much as half of atmospheric aerosol in the stratosphere could contain metallic particles from spacecraft.<\/p>\n\n\n\n Other organizations are also looking to use wood in space.<\/p>\n\n\n\n Finnish startup Arctic Astronautics designed the WISA Woodsat, a wooden satellite that was supposed to be launched into space in 2021. However, company founder Jari M\u00e4kinen says the launch has been held up by bureaucratic hurdles.<\/p>\n\n\n\n \u201cThe satellite is ready, waiting in pieces to be put together again when the time comes,\u201d M\u00e4kinen told CNN in an email, adding that once the company receives its space operations license, the satellite will be launched with private rocket rideshare service RocketLab.<\/p>\n\n\n At Khalifa University in the United Arab Emirates, <\/strong>aerospace engineer Yarjan Abdul Samad<\/a> is looking at graphene as a potential material for space objects.<\/p>\n\n\n\n Samad is exploring \u201cnano-wood\u201d \u2014 a low-density wood combined with graphene to improve its strength. Samad agrees with Murata that as a renewable and low-density material, wood has the potential to not just build satellites, but future space structures.<\/a><\/p>\n\n\n\n \u201cThere are many research (projects) going on for space agriculture,\u201d says Samad. \u201cIf we have wood grown in space, it could be utilized for manufacturing in space.\u201d<\/p>\n\n\n\n However, there are still a lot of unknowns about wood in space structures, says Tatsuhito Fujita, an engineer at JAXA who has been involved in reviewing the LignoSat project.<\/p>\n\n\n\n \u201cThe use of natural resources for space hardware (makes sense) from a sustainable development goals perspective, but since wood has never been used in satellites, we cannot tell what kind of benefit we can obtain at this moment,\u201d says Fujita.<\/p>\n\n\n\n For JAXA and the J-Cube Program, the initiative launching the satellite, the priority is safety \u2013 and the LignoSat passed its preliminary evaluation with no critical concerns, says Fujita. \u201cJAXA also hopes for lighter, stronger structural materials that are less likely to generate debris, and is conducting research to achieve this goal.\u201d<\/p>\n\n\n\n The LignoSat is in the final stages of its safety review <\/em>and is expected to launch in a joint mission by JAXA and NASA in the summer of 2024.<\/em> Murata says they will monitor the satellite for a minimum of six months, to see how it performs in space conditions \u2014 such as the extreme changes in temperature in space.<\/p>\n\n\n\nMagnolia, cherry and birch<\/h3>\n\n\n\n
![\"Engineers](\"https:\/\/media.cnn.com\/api\/v1\/images\/stellar\/prod\/231030144003-03-wooden-satellite-image-kyoto-university.jpg?q=w_1110,c_fill\")
Sustainable satellites<\/h2>\n\n\n\n
![\"Engineers](\"https:\/\/media.cnn.com\/api\/v1\/images\/stellar\/prod\/231030143853-02-wooden-satellite-image-kyoto-university.jpg?q=w_1110,c_fill\")
To infinity<\/h3>\n\n\n\n