Valerie Singleton, John Noakes and Peter Purves team up to present a series of programmes celebrating the 40th anniversary of the show that led to phrases such as "Here's one I made earlier" and "Get down, Shep" becoming ingrained on the nation's psyche.
How or why it became such a success is unclear, but it clearly grabbed children's imagination in a way no other programme did - or has since.
For the presenters, the joy of Blue Peter was the chance to do the things most people dream of. Valerie Singleton, who presented the programme between 1962 and 1972, said: "I always liked the part where we got to touch the exhibits, where most people could only look."
Saturday's specials will include Carry on Blue Peter, with bloopers and out-takes, It's a Dog's Life, about the Blue Peter dogs, and A Right Royal Reunion, with Valerie Singleton talking to the Princess Royal about their 1971 Kenya trip.
The following Friday, on the anniversary of the programme's first showing, a special 40th birthday edition with past presenters will be aired.
Peter Purves, who joined in 1967, said: "At the time I wasn't aware of its immense appeal. I remember the renaming ceremony for the restored Blue Peter locomotive where 50,000 people turned up. The police were unprepared for it."
For 40 years, the appeal has never really waned. Blue Peter has become a cornerstone of the BBC. The regular features such as the "makes" (with parents being pestered for washing-up bottles), appeals (raising pounds 25m over the past 15 years) and summer expeditions played their part in creating a continuity that helped to keep children watching.
Valerie Singleton said she has seen changes but the show still keeps the bare bones that make Blue Peter special: "All the things you now associate with it came about when I was on the programme."
Stuart Miles, the longest serving current presenter, believes there are two main reasons why the show remains as popular as ever: "One is that there's something comfortable about it, with the presenters and pets, and the other is that there's always an edge to what goes on. You never know what's going to happen this week."
The show has had 25 presenters, 26 if you count Anita West who was on for six months before being replaced by Valerie Singleton. She is never mentioned in BBC archives, although one of the programmes on Blue Peter night promises to set the record straight.