That grainy 1970s film that reminds you of the old “ Asteroids” video game may be the only footage we ever see of the Knicks winning a championship at the current Madison Square Garden.

According to the Daily News, over the fierce objections of MSG owners, the city Planning Commission opted to renew its operations permit for just 15 years on Wednesday — pushing the World’s Most Famous Arena to move from 4 Pennsylvania Plaza to make way for a revamped Penn Station project.

The move, which had the full support of Mayor Bloomberg, blindsided arena owner James and his brother Jim Dolan, executive chairman of the Madison Square Garden Company and could disrupt the flow of their extensive cake-stacking machine .

James Dolan, had been seeking a renewal “in perpetuity” while he carried out $1 billion in renovations that upgraded seats, luxury suites and more.

“We are extremely disappointed in today’s vote,” the Garden said in a statement.

Of course the MSG heads are vexed. You can’t relocate to a more financially fertile ground than next door to Penn Station, and when fans get a good whiff of this “backroom” deal, they will be tight too.

Forcing MSG to bounce from its lofty midtown perch would definitely be a game-changer. The Garden has been a symbol of NYC’s rich history, and one of the world’s treasured sports and entertainment landmarks.

Fifteen more years, huh?

“It isn't like tomorrow,” Bloomberg said. “It isn't like they're investing their money and never going to get it back.”

In politics, 15 years is forever. In sports, that's no time. About the length of one fortunate career. Melo, Woodson and Co. better get to work.