Three-for-three

As soon as the astronauts in a space shuttle succeed in releasing a satellite, the officer in Mission Control Center Houston says to them "congratulations!Three-for-three!
Would someone help me with the phrase"three for three",please? What does it mean?

The phrase means that 3 things were attempted and one was successful all 3 times. "3 out of 3" is also used, and of course, the numbers can be changed to fit any particular situation.

I would guess that the meaning comes from baseball and the calculation of batting average. An alternative phrase is "batting a thousand".