Tuesday, July 6, 2021

First Plywood Satellite Passing Early Tests

"Plywood satellite?"  Yes.  It hasn't gotten much conversation, but the Finnish plywood company Wisa has been working toward putting the world's first plywood satellite into orbit by the end of this year.  It will be built out of the same birch plywood they sell to anyone, but with some custom coatings that are intended to protect it in the vacuum on orbit.  As the company themselves explain: 

One of the most common questions we get is "Why plywood?", and our answer is "why not". Dried plywood is like a natural composite material having its own positive and negative properties – just like all other materials.

The main idea behind WISA Woodsat is to test how plywood behaves not only in space, but also when building a satellite.

In general, the materials used in spacecraft have to be lightweight, impact resistant, electrically conductive, non-magnetic and they have to heat up and cool down easily.

The satellite is being designed and built in Finland following the popular Cubesat format.  The satellite is roughly 10 x 10 x 10 cm, or just under 4" on a side,  the size of a 1U CubeSat.  They are working toward a launch date "before the end of the year" on a Rocket Lab Electron rocket from the Mahia Peninsula launch complex in New Zealand.  

Think of this mission as pure research, a technology proving flight, trying to determine how treated plywood handles the hazardous environment on orbit.  I may be ignorant of everything done with satellites, but all of the ones I've ever worked on were primarily built of aluminum alloys, with differing metals (if need be) based on the physical properties required for a certain spot. 

Wisa says:

The mission of the satellite is to test the applicability of wooden materials, especially WISA-Birch plywood in spacecraft structures and expose it to extreme space conditions, such as heat, cold, vacuum and radiation, for an extended period of time.

They don't say how that will be measured, whether some sensors or just video observations.  For the radio downlink, they're working on using a low data rate communications systems that some hams have been running, called LoRa (Long Range).  There is a worldwide emphasis now on ensuring that satellites with limited missions like this deorbit and don't just become space junk, but I don't see the expected lifetime on orbit.  

Back on June 14th, the first test of the satellite was completed, using a balloon to carry it to an altitude of 31.2 km, so very far short of being in space but at 102,000 feet it was well above conventional aircraft traffic altitudes.  The system was designed for the balloon to pop after some time at altitude and the satellite recovered.  The moment the balloon popped was captured by its onboard camera.

“All the systems performed as planned during the test flight. The satellite landed eventually in a forest area at Herrala, close to lake Hahmajärvi. The recovery team was on site soon after the landing, but the recovery took a bit more time than expected as the flight equipment had landed on the top of high spruce tree”, says WISA Woodsat mission manager Jari Mäkinen.

As of the end of June, they're constructing the flight satellite and its spare, and everything seems to be going on schedule for a flight.  It's a unique little story and I'll try to keep an eye out for updates as we go forward.



3 comments:

  1. Damn!....why do parachuted things always seem to land in the top of a very tall tree!
    :-)

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  2. Do they know how expensive that stuff is?

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  3. grammar nazi in sniping position:
    I believe järvi in Finnish means lake; sort of like when people say Mount Fujiyama, yama means mountain in Japanese.

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