Moonshot to cure cancer? We’ve heard that before. Many times.

If the Obama administration’s moonshot to cure cancer sounds familiar — well, there’s a reason.

Presidents have been promising to do just that for 45 years.

Richard Nixon launched the metaphor that would not die way back in 1971, declaring that “the same kind of concentrated effort … that took man to the moon should be turned toward conquering this dread disease.”

Scientists then were just as skeptical as they are now, arguing that it’s inappropriate to call for a single, triumphal moonshot when cancer isn’t one disease but many. “We aren’t ready to start a countdown to an anticancer blastoff,” Philip Lee, then the chancellor of the University of San Francisco, told the Pittsburgh Press in 1971.

Nixon, of course, also invoked a “war on cancer.” Decades later, with the war still not won, the Clinton administration turned again to that militaristic metaphor.

“We want to be the first generation that finally wins the war on cancer,” then-Vice President Al Gore told the Toledo Blade in 1998. He said science was on the verge of a breakthrough: “For the first time, the enemy is outmatched.”

It wasn’t.

In the following campaign, Republican presidential nominee George W. Bush returned to the space metaphor. He promised to “fund and lead a medical moonshot to reach far beyond what seems possible today,” to cure not just cancer but many ills associated with aging.

Sixteen years later, President Obama and Vice President Joe Biden are launching a new effort.

“Research and therapies are on the cusp of incredible breakthroughs,” Biden wrote in a post in Medium this week. “The science is ready.”