Dr Chris Smith and the Naked Scientist team present the latest science news, analysis and breakthroughs. This week, as AstraZeneca acknowledged that their COVID vaccine is linked to a rare blood clotting side effect, we find out more about it. Plus how scientists are getting closer to cracking nuclear fusion, and how adding bacteria could be key to breaking down plastic. We also discover how zero gravity affects the body, and how science is looking at the future impact of long journeys away from Earth ahead of further exploration into space. Get the podcast from the BBC Sounds app.