Discovery’s ‘When We Left Earth’ debuts Sunday

It’s always kind of fitting when the U.S. space program is featured in a TV series. For millions of viewers, those early space missions played out as a thrilling TV series, with the real-life story line becoming more amazing and suspenseful with each flight

Looking back, it still is. “When We Left Earth: The NASA Missions” is a three-part look back that marks a half-century of U.S. manned space flight. It launches on Discovery Channel at 6 p.m. Sunday.

Giving the series a never-seen-before vividness, Discovery has transferred original mission footage to high definition, giving these archival records heightened power.

It all begins, of course, with the pioneering Mercury program and its quest to put a man in space. NASA hand-picks seven men as a new breed of hero.

Would getting blasted into space from atop a rocket kill a human or drive him insane (assuming the whole contraption didn’t blow up)? The 15-minute flight of Alan Shepard argued otherwise as, in May 1961, he triumphed as the first American in space.

Week two is devoted to the Gemini program, whose missions paired astronauts and introduced them to walking in space.

Then a few giant leaps, and Neil Armstrong made his “one small step” onto the moon. That’s where the miniseries is headed for its third week. Then the shuttle mission, with the Challenger disaster. Even now, the sight of that explosion is a shocking reminder: This was all never just a TV show.