"failed mission" is correct and usable in written English.
You can use this phrase when referring to a mission that did not achieve its intended goals. For example, "The team's failed mission to find the lost relic was a disappointment to all."
The failed mission to rescue hostages in Iran in 1980 also loomed large.
Now the failed mission has exposed Mr. Chávez to criticism of misplaced priorities.
Ronald Reagan made the failed mission an issue in defeating Mr. Carter in his bid for a second term.
The failed mission became an issue in the 1980 political campaign in which Mr. Carter was defeated by Ronald Reagan.
The failed mission eventually ended after 18 American peacekeepers were killed and dragged through the streets of Mogadishu.
That failed mission is not the reason Gillick appears on the Hall of Fame ballot for the first time this year.
After his two earlier failed missions, the consensus has been that the Americans need some larger idea if a cease-fire is to hold.
Long before last Friday's crash of Virgin Galactic's SpaceShipTwo in the Mojave Desert, the economist Brent Lane had been thinking about failed missions and Sir Richard Branson, Virgin's adventurous founder.
Last week's incidents occurred just as the United Nations was building up a presence -- with 8,300 soldiers already here -- on a continent that the international community had avoided in recent years, after failed missions in Rwanda and Somalia.
Prompted by criticism over failed missions, the National Aeronautics and Space Administration has chosen Dr. Firouz Naderi, a veteran manager of space projects, to head a newly formed Mars program aimed at improving future robotic explorations.
Although the Phoenix lander, a conglomeration of parts from two earlier failed missions, has been tested and rechecked to correct all known design flaws and potential errors, Dr. Weiler said, "there are always the unknown unknowns".
