"essential mission" is a correct and usable phrase in written English.
It is mostly used to describe an important goal or purpose that must be accomplished. For example, "Our essential mission is to protect the public from harm."
"In reality," said Prime Minister Javier Pérez de Cuéllar, the agency "serves an essential mission".
Therefore, we expect, and success demands, that the administration not lose sight of this essential mission.
There's no need to change the BBC's essential mission or its values.
And it will help drive the cruise industry — notorious polluters — to re-examine its essential mission.
Finding the true, authentic New Orleans is that show's essential mission, its quest.
After last year's terrorist attacks, the search for coherence and humanity turned into an essential mission for survival.
Recruit the "black sheep". Adding those essential mission-critical capabilities will inevitably require recruiting well-trained experts from big, incumbent companies.
We are asking ourselves: What are the essential missions our military must do to protect America and our way of life?
The headquarters of the North American Aerospace Defense Command, or Norad, in Colorado were evacuated for about four and a half hours on Thursday after employees found five suspicious packages, but the command's control room team was working at a backup location eight miles away, and no essential missions were disrupted, officials said.
How can institutions best be kept institutionally strong and focused on their essential missions?
Assessing and preventing human and zoonotic infectious diseases in tropical areas, particularly Africa, are essential missions of the French Defense Medical Service.
