People have always been fascinated with the moon, stars and planets. “Space exploration captures the imagination and helps us understand who we are, where we came from and where we’re going,” said NASA’s Joshua Buck. “With an expression like ‘Houston, we have a problem,’ we’re tapping into our collective memory to communicate quickly and easily.”
These idioms all draw on space and space travel.
Once in a blue moon

In space: A blue moon isn’t actually blue. It’s just a name for a second full moon in one month of the solar calendar. This only happens every two to three years.
In conversation: People say something that happens rarely happens once in a blue moon. “They give away free samples at that falafel stand, but only once in a blue moon.”
“Houston, we have a problem.”

In space: In 1970, Apollo 13 was intended as the third manned mission to land on the moon. Everything went well until one of the two oxygen tanks exploded. Astronaut Jack Swigert’s terse announcement to Mission Control (located in Houston) was by-the-book astronaut talk.
In conversation: Even though many people don’t realize they are quoting Swigert, they do it when they realize all at once that something has gone very wrong. Usually, the line is used when minor inconveniences occur, to humorous effect. “I made a beautiful cake, but I think I left out the baking powder. Houston, we have a problem.”
Rocket scientist
In space: Aerospace engineers (rocket scientists) who design spacecraft and satellites are at the forefront of technology, putting men on the moon and, more recently, landing a probe on a comet moving at 130,000 kilometers per hour. Americans hold the brainpower of these men and women in high esteem.
In conversation: Most often the phrase is used to negate any sense that a task is difficult. “It’s a microwave oven. You don’t have to be a rocket scientist to turn it on.”
Failure to launch

In space: Launching anything into space is tricky business, and thousands of details can cause a launch to fail.
In conversation: The phrase “failure to launch” sometimes refers to adult children who don’t move out of their parents’ home when expected and sometimes to potentially romantic relationships that fizzle. “We had a few dates, but it didn’t go anywhere — failure to launch.”
Other resources for learning English
The American English website has a variety of free resources for learners and teachers of English. The American English Facebook page posts learning materials for English language learners daily.
The Voice of America offers news stories and podcasts that help students at different levels. And thanks to NASA, now you can even download space-themed ringtones to your phone.
Other idioms that are common in the everyday speech of Americans include those derived from sports, business and cooking.