In 1969, Buzz Aldrin became the second man to set foot on the moon's surface. The next to walk on the moon may not be an American: Barack Obama has cancelled the next generation of moon landings to save money. Aldrin explains why he backs Obama's proposed budget cuts.

Plus, Mark Shuttleworth paid for the privilege of eight days aboard a Soviet spacecraft and became the first African in space. He debates the future of space travel with space sceptic Jerry De Groot, the author of The Dark Side of the Moon.

Zimbabwean politician, Sekai Holland, is a founding member of the Movement for Democratic Change. Three years ago she was brutally beaten by the country's security police. Today, following last year's power-sharing agreement, she is the new minister for national healing, reconciliation and integration.

Sir David continues his interview with the actor and comedian Billy Connolly. They talk about what he missed most when he decided to give up alcohol.

The economy is in trouble again. European stock markets are rapidly falling due to concerns about debt repayment in Portugal and Greece. Portugal is facing a political crisis over the country's economic troubles. Fernando Teixeira Dos Santos, Portugal's finance minister, joins the show to discuss this.

Plus, Alex Brummer, the city editor of the UK's Daily Mail newspaper, analyses the financial crisis facing Europe and Alex Stubb, Finland's foreign minister, talks about the relationship between the European Union and the US.