WHEN Neil Armstrong made his "one giant leap for mankind" stepping on to the moon, little did the billions of incredulous viewers glued to their TV screens watching the event realise there was an Anglesey man behind the operation.

Tecwyn Roberts, from Llanddaniel Fab, played a major part in the space mission. His amazing story is being told for the first time in a new documentary presented by comedian and BBC Radio Cymru presenter Tudur Owen.

Rocket Man: NASA’s Welsh Hero is on BBC One Wales at 10.35pm, on Thursday, July 18.

The film is part of the BBC’s celebration of the 50th anniversary of the moon landings, and sees Tudur reveal the story of how a shy boy from Anglesey helped men walk on the moon.

Tudur said: “Tec Roberts’ story is incredible and I feel so privileged to be able to tell it to the people of Wales.”

Becoming NASA’s first flight dynamics officer (FIDO), Tecwyn was instrumental in the Apollo missions.

Tudur travelled to America to find out more about Tecwyn, and talked exclusively to three of his former colleagues and fellow engineering legends - including former director of the Johnson Space Center, Christopher Colombus Kraft Jr, who emphases the importance of Tecwyn’s role in the moon landing.

The documentary features remastered NASA archive footage, and celebrates the little known engineer.

Tecwyn was born in 1925 and raised in an unassuming cottage Trefnant Bach on the outskirts of the village of Llanddaniel Fab.

He was a pupil at Parc Y Bont primary school. Successful in the Scholarship Examination in 1938, he went on to Beaumaris Grammar School.

Afterwards he started an engineering apprenticeship with Saunders-Roe, at Fryars Point, at Beaumaris, where Catalina flying boats were converted and maintained, before embarking on his epic career.

Tudur continued, “This humble and gifted man from Anglesey is regarded by NASA as one of the pioneers of manned space flight.

“My mission is to make sure that his work and legacy is recognised here in Wales.

“I am so excited to be able to tell Tec Roberts’ story. The whole world knows about the moon landing but only a select few know about the crucial role this unassuming and gifted Welshman played in mankind’s greatest achievement.”

Christopher C. Kraft Jnr – also a former NASA Flight director said “Tec really knew what the hell he was doing. I feel like I was damn fortunate to have that man in my pocket.”

“He was like a brother to me; a little better. People like Tec Roberts, who you could trust implicitly and know that were going to do a good job, were rare and he was one of those and I thank him for it and I don’t think he ever got the credit.”

George Abbey, former director of the Johnson Space Centre said: “We couldn’t have done the landing without him.

"He was responsible for all the communications that we had, the television we saw, the data that came in and he had to make sure it happened and happened the right way.

"I’m very proud of him and proud that we had a Welshman playing such an important role in all that activity and the people of Wales should take great pride in that.

Glynn Lunney, former flight director on Apollo programmes started as an apprentice under Tecwyn.

“I’m very proud to have been a friend of his. They were great times. Tec was a man that was easy to like, he was gentle and we loved him. One of the things that struck me very quickly about Tec, he was positive about things, he was positive about finding solutions, he didn’t get uptight about things.

“I wrote somewhere in my notes once in my life that all 22 year olds ought to have a couple of years working for a guy like Tec. If they got that then they were fixed for life.”

Tecwyn Roberts, who was married to Doris, died on December 27, 1988, aged 63. He was buried at St. Stephens Episcopal Cemetery, Crownsville, Maryland.

A plaque was recently erected at his former home Trefnant Bach by its current residents. It reads: “Tecwyn (Tec) Roberts 1925-1988 was raised here.

As NASA’s first Flight Dynamics Officer he was instrumental to the success of landing a man on the moon,” and is accompanied by a Welsh dragon and the NASA logo.

Rocket Man: NASA’s Welsh Hero is on BBC One Wales at 10.35pm, on Thursday, July 18.

(A Welsh version is on S4C Tudur Owen: O Fôn I'r Lleuad, is on Sunday, July 14 at 8pm.)