Japan's wooden cube-shaped satellite rockets to space

Japan's wooden satellite has been launched into space aboard a SpaceX Falcon 9 rocket with a mission to prove that wood can be a viable material for use in space. Lignosat wooden satellite for greener space Credit: KyotoU/Gakuji Tobiyama An artist's impression of LignoSat (click to enlarge) Credit: KyotoU/Gakuji Tobiyama …

[H in The Hague]

According to the article "... wooden satellites [...] require less electromagnetic shielding, therefore allowing for a smaller design"

It would be nice to have an explanation of that - why would they need less shielding? In fact as the metal enclosure of a conventional satellite is likely to provide a degree of shielding of the electronics inside it, if anything you would expect a wooden satellite to need additional shielding. Or is my extremely limited grasp of shielding and EMI sorely lacking?

[james 68]

That was my thought too.

Then I considered ionisation, a metal structure would provide a path for the charge accumulated by ionising radiation whereas wood would act as an insulator? I ain't a rocket scientist so that's just a best guess.

[Hans Neeson-Bumpsadese]

I'm with you - wood as a better magnetic shield than metal doesn't sound right to me either.

[STOP_FORTH]

Is it possible that wood produces less secondary radiation when it interacts with cosmic rays, solar wind and all the other bad stuff up there?

Or is it because wood is considerably less dense than metal and presents fewer nuclei as targets?

[bombastic bob]

wood is better at shielding neutrons, but you'd need it to be 2-3 feet thick to shield 90% of them...

However that may work out, a wood shell is necessarily thicker to provide equivalent strength as metal, so maybe THAT has something to do with it.

[/me cannot get wooden cyberman image out of my head]

[tony72]

Water is a good shielding material for space radiation, so I'm wondering if it's the water content of the wood that might do it? But a) I'd have thought you'd need a thick bit of wood for that to work, and b) I'd have thought the wood would lose moisture once exposed to space. Yes, definitely more info required on that.

[CrazyOldCatMan]

Water is a good shielding material for space radiation

I hear that oysters are good for shielding from the Pain of Space:

https://en.wikipedia.org/wiki/Scanners_Live_in_Vain

[tony72]

Sounds like a bit of a weird story. I may check it out.

[pdh]

I found a few sources saying that since wood is transparent to the radio frequencies used for communications, satellite antennas can be inside the body of the satellite rather than being unfurled outside, which is a simpler design. But that still doesn't make sense, unless it happens that wood is also opaque to the radiation that makes up damaging cosmic rays.

[bombastic bob]

shielding can be estimated by "10th thickness", i.e. how thick to reduce radiation to 1/10 of what it was.

Thickness depends on radiation type. For alpha (He nucleus) and beta (electrons emitted by a nucleus) it's usually a millimeter or so.

For gamma it's about 1 inch of lead, 2 inches of steel, 1 foot of concrete, and 3 feet of water (if I remember correctly). Mass and density are major factors.

For fast neutrons it's different. You need hydrogenous and other light materials (carbon helps some) to slow the neutrons down so that they do way less damage. For water, it's about 1 foot. Plastic containing boron 10 reduces that down to an inch or so because boron 10 absorbs neutrons, but it depletes (becomes boron 11) so wears out over time.

So to shield gamma you need dense material, and to shield neutrons, hydrogenous material [like water, plastic, wood, oil, ...] and/or absorbing material (like boron 10).

[alain williams]

What sort of wood ?

Plywood or some hardwood or what ?

[bombastic bob]

Re: What sort of wood ?

Article: "The wood used in its construction is Honoki, a type of Japanese magnolia tree"

details like that are easily missed, though, and also they did not specify particle vs ply vs regular as far as I can tell.

[O'Reg Inalsin]

Re: What sort of wood ?

Hinoki cutting boards (for food prep) are popular - many can be seen on the net.

[EricB123]

Re: What sort of wood ?

Not sure about that, but the price of wooden chopsticks in my alley supermarket has definitely increased lately. Wood buildings, now wood satellites, wood shortage?

[Eclectic Man]

We Are Groot

Shirley this should be called 'GrootSat'?

There was a programme on the BBC Radio 4, I think, quite recently about the use of wood rather than metals for making aircraft. Wood actually being a lot better for some components, as it is lighter for the same amount of strength and has other useful properties such as thermal insulation, but for some reason teh engineers wanted to work with metal.

Puts me in mind of the price of 'birds eye Maple': https://www.youtube.com/watch?v=zflGtguyAR4

For the words see:

http://www.goldenhindmusic.com/lyrics/THREEHAP.html

[martinusher]

Re: We Are Groot

A couple of WW2 era aircraft were built out of wood using 'modern' techniques. Early planes were built a bit like traditional furniture with a wooden frame covered in material but that type of construction isn't suitable for mass production -- good for a one off garage project, not so good for something that needs to be manufacturable. Starting with the WW2 Mosquito plywood started to be used extensively as structural material and proved to be really good (although not without problems). Once you add carbon fiber to the laminate then you can make really strong material.

[STOP_FORTH]

Re: We Are Groot

Up to a point, Lord Copper.

The Hawker Hurricane was constructed by draping Irish Linen over a wooden frame. They had to use metal for the engine, machine guns and some tubes forming an interior frame.

First RAF kite to fly at 300 mph.

Of course, when Concorde was designed they couldn't get the wood any more so had to make do with metal.

[RM Myers]

What will they think of next

Will someone create a paper aircraft and release it into space? The vultures will be circling waiting for its release.

Man, I miss Lester. So many great articles. Thanks for the memories.

[Oninoshiko]

Re: What will they think of next

Here's the link if you want to go back and have a look again.

https://www.theregister.com/2010/11/05/paris_aerial_pics/

[ravenviz]

Brilliant idea! They could even make really small satellites out of bonsai trees.

[Francis Boyle]

And really big ones

out of bamboo scaffolding.

[cantankerous swineherd]

it's going to exude

[sorry not sorry]

chemtrails

[Chris Evans]

Photo?

Some very good photos of it are here:https://www.nanosats.eu/sat/lignosat

[John Robson]

There were also wooden heatshields

At least there were plans for them, it's not entirely clear whether they flew.