Inventing the Impossible: The Big Life Fix, BBC2, 8pm
IF you’ve missed the previous runs of this fascinating and frequently moving series (when it was known as The Big Life Fix with Simon Reeve), it sees a team of inventors putting their skills at the disposal of people who want to overcome the obstacles between them and their dreams. In the first episode, they include 40-year-old Graham, who was a passionate snowboarder until an accident left him with limited use of his arms and legs. There are skis and snowboards available which have been adapted for the disabled, but none of them can help Graham. Can award-winning engineer, Yusuf Muhammed, come up with a solution?

Size Matters, BBC4, 9pm
IN the first of the two-part documentary, Hannah Fry asked what life would be like if Earth and its inhabitants were bigger. Now she’s looking at what would happen if everything was smaller, and discovers that if our planet shrank, we would all be suffering from altitude sickness – even at sea level. She looks at why shorter people live longer and small creatures defy the laws of physics.

Keeping Faith, BBC1, 9pm
THE lawyer finds herself in custody on suspicion of murder, and butts heads with DI Williams, who is convinced Faith knows more about Evan’s disappearance than she is letting on. Despite her own problems, when Faith encounters family friend the Reverend Talbot at the station, she represents him on charges of mis-using church funds. Meanwhile, Tom enlists the help of DCI Parry to look into his son’s files, while Lisa tracks down a lead at a lap-dancing club Evan was known to visit.

Horizon: Spina Bifida & Me, BBC2, 9pm
ONE in every thousand babies born in Britain has a spine or brain defect like spina bifida. Thirty years ago, actress Ruth Madeley was one such newborn, but despite having spina bifida herself, she does not fully understand the condition. Here she sets out to discover why she has it, whether it could have been prevented and what it means for her future. She also meets the lord who says a law change could prevent thousands of birth defects and discovers how pioneering foetal surgery could offer a different future for babies diagnosed with the condition.