We've heard this song before, not that we don't enjoy the tune.

President Donald Trump stood before the nation on Monday and signed a directive ordering NASA to send astronauts to the moon. Consider it a reversal of the Obama administration's Mars-first plan that, so far, resulted in a single launch of the Orion capsule.

Second verse, same as the first.

The audience watching at home got to see the president make his announcement and shake hands with Houston's U.S. Rep. John Culberson - a major NASA fan - before darting out the back door.

That's probably the most action you can expect to get out of "Space Policy Directive 1."

Rockets may run on liquid hydrogen, but NASA runs on cash. Or as they said in "The Right Stuff:" "No bucks, no Buck Rogers."

At its peak during the moonshot era, the space agency consumed more than 4 percent of the federal budget. Now it hovers around one-half percent. Trump's budget request from earlier this year would have slashed that even further, and the Senate still hasn't confirmed his nominee for NASA administrator.

It is a simple budgetary fact that NASA cannot send a manned mission to the moon, let alone Mars, while also maintaining the International Space Station. Until Congress adds more funding, these promises of astronauts' footprints on lunar soil will be just that - promises.

When Congress does add money to NASA, there's no guarantee it will be spent on manned missions. Culberson has made it a personal priority to fund an $8 billion series of probes to explore the Jovian moon Europa, which he thinks may harbor alien life. Not a cent of that is likely to be spent at the Johnson Space Center in Houston.

Sometimes it feels like Houston's current role as Space City has shifted from making history to preserving history. At this point, it has almost become a tradition for presidents to tout NASA in a hamfisted attempt at grasping a "vision thing" - as Bush 41 put it - after the White House honeymoon starts to fade. Usually that doesn't happen until after the first year in office.

We're glad that Trump has put a new focus on NASA, but until funding catches up with the mission, he's just whistling that same old tune past the launchpad.