The science behind yo-yo diets, bird flu news and which Brits can spot a fake accent

It’s a dream for many children, but what does it actually take to become an astronaut? Science correspondent Hannah Devlin tells Ian Sample about her trip on a zero gravity flight with the European Space Agency (Esa). Back on solid ground she also got to speak to Rosemary Coogan, one of Esa’s newest recruits, about the rigorous process that led to her being chosen from more than 20,000 applicants, to become an astronaut, and what she hopes to achieve in her role. Help support our independent journalism at theguardian.com/sciencepod

At a moment when the world feels like a particularly unsettling place, Science Weekly is asking what it is that makes humans happy – and how we can bring more happiness into our lives. In episode two, Ian Sample asks which happiness strategies are backed up by science. He hears from Elizabeth Dunn, a professor of psychology at the University of British Columbia, who recently scrutinised a whole lot of happiness research to work out which recommendations are most reliable. Help support our independent journalism at theguardian.com/sciencepod

At a moment when the world feels like a particularly unsettling place, Science Weekly is asking what it is that makes humans happy – and how can we bring more happiness into our lives? In episode one, Ian Sample asks what makes a country happy? Johannes Eichstaedt, assistant professor of psychology and human-centred AI at Stanford University, explains why the Nordic countries often rank highly in the annual World Happiness Report, and what we can learn if we look beyond them. Help support our independent journalism at theguardian.com/sciencepod

Madeleine Finlay talks to science editor and podcast co-host Ian Sample about how Donald Trump approached science when in office last time, and what his second term is likely to mean for the environment, health and scientific research. Help support our independent journalism at theguardian.com/sciencepod

Space-settling enthusiasts have long had an eye on Mars, and now they have the backing of the world’s richest man. Elon Musk recently claimed that humans could be on the planet by 2030 and be living there in a self-sustaining city within 20 years. But is it really that simple? Madeleine Finlay heads to Imperial College London where Prof Sanjeev Gupta gives her a tour of the red planet, and meets Kelly Weinersmith who, along with her husband, Zach, recently won the Royal Society Trivedi science book prize for their book A City on Mars. She explains why life on Mars may not be the idyll some would have us believe. Help support our independent journalism at theguardian.com/sciencepod