Nasa on return to Moon and Mars

As Nasa marks the 40th anniversary of the historic Apollo 11 mission to the Moon, one of the organisation's top officers has spoken about plans to return to the lunar surface, and go on to Mars.

In an interview with the BBC's Kevin Connolly, Nasa's manager of Space Station Operations John Olson said he was not alarmed by the Human Space Flight review ordered by President Obama, and defended spending on space exploration during a time of economic turmoil.