Japan To Launch Wooden Satellites

We may have wooden satellites in just a few years, according to an announcement this month by Kyoto University and Sumitomo Forestry, organizations whose combined roots go back 550 years.

Wood’s place in high-technology has a long track record. During World War 2, wooden boats were used for minesweepers, the Spruce Goose was designed to circumvent wartime material restrictions, and Britain’s plywood-built De Havilland Mosquito had a very low radar cross section. In this century, a man in Bosnia has even built a Volkswagen Beetle out of oak.

The newly-announced aerospace project, led by retired astronaut and engineer Prof Takao Doi, plans to launch satellites built from wood in order to reduce space debris and hazardous substances resulting from re-entry. We’re somewhat skeptical on the hazardous substances angle (and we’re not alone in this), but certainly as a way to help ensure complete burn up upon re-entry, wood is an interesting material. It also achieves a great strength to weight ratio and as a renewable resource it’s easy to source.

Prof Doi has been studying the use of wood in space for several years now. Back in 2017 he began basic research on the usability of timbers in space (pg 16), where his team experimented with coniferous (cedar and cypress) and hardwood (satinwood, magnolia, and zelkova) trees in vacuum environments. Based on successes, they predicted wooden satellite launches in the mid 2020s (their announcement this month said 2023). Sumitomo engineers have not released what kind of wood(s) will finally be used on the satellite.

You might remember Astronaut Doi from an experiment aboard the ISS where he successfully demonstrated flying a boomerang in space (video below), and he’s also discovered two supernovae in his spare time. We wish him good luck.

48 thoughts on “Japan To Launch Wooden Satellites

  1. sorry to be a nitpicker.

    “a man in Bosnia has even built a Volkswagen Beetle out of oak” should be: “a man in Bosnia has even covered a Volkswagen Beetle with oak”

    and don’t forget the wood gas driven Citroen DS from Joost Conijn. completely covered with triplex.

      1. Didn’t Ford do work on using soybeans to make car bodies?I

        I actually have plates made of bamboo, but it feels like plastic so I assume they process the bamboo into a sort of plastic like compound.

        1. “The Mosquito had a very low radar cross section” yeah, no. This is an annoyingly persistent myth that’s even mentioned in some otherwise authoritative sources. While it’s wooden structure was not a great radar reflector, the engines, spinning props, metal lattice cockpit canopy frame, armour plate, control rods and cables, guns, seats, ammunition, radar antennas, oxygen bottles, fuel tanks, fuel lines, radiators, undercarriage, bomb load etc, etc, etc, mean that it was not appreciably more difficult to detect than any aircraft of comparable size. It’s basically a collection of great corner reflectors flying in tight formation. Yes it carried an IFF transponder, all British fighters did. Yes Galland said it was “difficult to track”, as you would expect for a smaller aircraft operating individually and capable of much higher speed than other Brit bombers and the German night fighters attempting to intercept them with 1940s radar for ground control. No, defeating radar does not appear as any kind of design requirement or objective in any readily available original documentation and there was no reason for the designers to even believe that this would be possible.

          1. It could have been a legend promulgated by the RAF themselves, due to the activities of No. 100 group, which was a special operations nightfighter hunter killer unit, which could detect nightfighters before they were detected themselves (Not hard even if your receivers are less sensitive, because of inverse square law and relatively weak signal of returns vs output) So using that they could plan to “appear out of nowhere”. But additionally they later had some ECM jamming equipment also carried in Mosquitos called Mandrel, which may have been secret long after the war, which rendered the German radars useless over a 100 mile radius. So putting about the “you can’t see them because they’re wood” was good plausible deniability for the existence of such systems.

  2. I would have thought that it would be wise to maximise the radar signature of anything that you put in space if you are trying to be helpful. Perhaps vapour coat the wood with a few atom thick layer of aluminium? If you are going to bother at all, it does seem like a silly gimmick with minimal if any real benefits and that it will never be applied at a scale where it would make a difference. Just 3D your parts in a thermosetting resin then heat it in an inert atmosphere until you have glassy carbon which you then metal vapour coat. Light , strong, dimensionally stable and very visible on radar. If you want to be very smart about it incorporate a long distance version of passive RFID where the modulation of the objects radar cross section is used to encode an ID number.

    1. I thought they were trying to limit the blockage from satellites. They are starting to put a lot of networked satellites in orbit, and they are starting to worry about how that will affect radio astronomy.

    1. Bamboo all the way, CRISPR up some giant bamboo genes so you can grow stalks wide enough to be used as boosters, then make cellulose nitrate type stuff out of bamboo and fine granular carbon from bamboo for your solid rocket propellant. Make all your fittings out of celluloid, viscose or polyester derived from bamboo. Refine silica from the ash of bamboo for making your chips with, encapsulate them with some glob of one of those plastics…. Hey, maybe get Malaysia or other South Asian country on board, fully “home grown” space program.

    1. I was yelling at the TV for 2 days straight on Columbia’s last mission, seemed they’d got so stuck in the refractive heat shield mindset that they forgot about ablatives and previous success of organic ablatives. I’d have had them pack the seat cushions in the hole if they couldn’t find a damn thing else. Everybody chew up a page of the flight manual and spit it in a pot and do papier mache, ANYTHING. It turned out that a lot of the engineers behind the scenes were trying to do their best, but management had already decided to murder the crew and blocked several efforts.

  3. Lets see: it cant burn, not much air above 50 miles high, can thermally ablate, but then so do metals. So I guess the point is to prevent assorted metallic oxides from doing (something) to the atmosphere. Afaik, not much of a difference, except it’s an ORGANIC pollution like fires in CALI . Mmm organic pollution, much healthier.

    1. Actually it’s good because wood splinters are a less harmful form of space debris due to lower density than the other materials in space. It can also be used to keep antennas inside the craft as it will transmit microwaves as good as dry wood. It is also lightweight compared to pretty much all metals and is stiff enough. Finally, unlike most metals, it will more effectively burn to carbon dioxide and water in the atmosphere.

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