The phrase "completed their missions" is correct and usable in written English.
You can use it when referring to individuals or groups who have successfully finished specific tasks or objectives, often in a context related to military, space exploration, or project management.
Example: "After months of hard work, the astronauts completed their missions and returned safely to Earth."
Alternatives: "fulfilled their objectives" or "accomplished their tasks."
In response to the annulment, the Russian military issued a statement saying its planes had already completed their missions.
We can count the ways: Use pay-as-you-go budgeting, means-testing for all government assistance programs, sunset provisions for agencies and programs that have completed their missions.
Let's return to limited government accompanied by a minimal amount of confiscatory taxation to support only essential services along with pay-as-go budgeting, means testing for all government assistance programs, sunset provisions for agencies and programs that have completed their missions, and an end to pork-barrel spending.
For the next four years, until the Shuttle fleet bowed out in 2011, the spaceships completed their missions without mishap.
The astronauts successfully completed their mission and returned to Earth on June 22.
"Spanish troops have spent time there and have completed their mission in Iraq," said Prime Minister José Luis Rodríguez Zapatero.
4. WRAP-UP/HOMEWORK: After groups have completed their mission plans, each member of the group will design an orbital space plane to carry out the mission.
It was as if by blowing each other to bits they had completed their mission and everything had gone perfectly swimmingly and according to plan after all.
"One of the things that we have been talking about, thinking about before the flight, is that they never really completed their mission," Mr. Lu said.
By the time the air force learned about the raid from ground reports at Abbottabad and launched fighter jets, the helicopters had completed their mission and flown out of Pakistan, he said.
The riders had completed their mission, traveling from Austin, Tex., and points along the road to join the protests outside the Republican National Convention; still they marveled at the city at night.
