BBC Four HD Wednesday

Michael Portillo continues his rail journey along the Upper Mississippi to Red Wing, Minnesota, and the home of Laura Ingalls Wilder, author of Little House on the Prairie

The presenter visits one of the windiest places on Earth, walks into the centre of a man-made tornado and employs fire to make a 10m-high whirlwind

The sleazy underbelly of London's Soho in the early 1970s, where an explosion of dirty pornographic bookshops provides an open invitation for corrupt police to be greedy

The writer looks back on the origins of her drama Happy Valley, which first appeared on the nation's TV screens in 2014

Crime drama by Sally Wainwright, starring Sarah Lancashire as a police sergeant battling her own demons when she becomes involved in the hunt for a kidnapped woman

John Wilson talks to TV writer and director Sally Wainwright about her life, work and creative process, including her early career writing for The Archers and Coronation Street

Exploring how space will revolutionise life on Earth over the next 50 years, with early access to a groundbreaking new report from the Royal Society on humanity's future in space

Michael Portillo continues his rail journey along the Upper Mississippi to Red Wing, Minnesota, and the home of Laura Ingalls Wilder, author of Little House on the Prairie

The presenter visits one of the windiest places on Earth, walks into the centre of a man-made tornado and employs fire to make a 10m-high whirlwind

The sleazy underbelly of London's Soho in the early 1970s, where an explosion of dirty pornographic bookshops provides an open invitation for corrupt police to be greedy