The timber satellite has been built by researchers at Kyoto University and the logging company Sumitomo Forestry in order to test the idea of using biodegradable materials such as wood to see if they can act as environmentally friendly alternatives to the metals from which all satellites are currently constructed.
Yeah, this is to reduce atmospheric pollution when satellites deorbit, which is a separate problem from ensuring satellites deorbit in the first place. I hadn’t heard that being an issue, but can see how it could be once the first generation of megaconstellation satellites (Starlink, Kuiper, and Guowang) reach the end of their life.
Incidentally Japan + Rocket Lab just launched a spacecraft to collect data for future orbital rendezvous and deorbit missions.
Looks like the research into upper atmosphere metallic contamination hasn’t been studied much yet, they just know it’s becoming more prevalent, but don’t know that problems that creates yet. https://www.pnas.org/doi/full/10.1073/pnas.2313374120