The phrase "a field mission" is correct and usable in written English.
It can be used to refer to a specific task or operation conducted in a particular location, often in the context of research, military, or humanitarian work.
Example: "The team was deployed for a field mission to assess the impact of the recent natural disaster on the local community."
Alternatives: "an on-site operation" or "a field operation".
We were a group of six on a field mission in the Republic of Guinea, investigating all aspects of a previously unstudied chimp community.
But, he said recently, he was thinking of moving to another job in the institution — a "field mission," as he put it — and so he was thinking of dropping by the World Bar soon.
A field mission hovering over an exhaust shaft of a roadway tunnel to collect air samples was performed to demonstrate the applicability of the multicopter-carried WASC apparatus.
Dr. Alipui led a field mission to remote villages in Mindanao during the campaign.
But I was also nervous, since this was my first time leading a field mission.
During a field mission to the arid region of Turkana in northern Kenya, Lake saw the silent face of the crisis.
Finally, results are summarized, and conclusions are drawn in Section 5. ESA's Swarm constellation is a geomagnetic field mission consisting of three satellites which carry an instrument suite similar to that of the CHAMP satellite (http://www.esa.int/Our_Activities/Observing_the_Earth/The_Living_Planet_Programme/Earth_Explorers/Swarm).
The proposed design tool consists of a real field mission profile model (for one year operation in USA-Arizona), a PV-panel model, a grid connected PV-inverter model, an electro-thermal model and the lifetime model of the power semiconductor devices.
After twice visiting Cambodia, while filming Lara Croft: Tomb Raider (2001) and on a UNHCR field mission, Jolie returned in November 2001 with her husband, Billy Bob Thornton, where they met Maddox and subsequently applied to adopt him.
In addition, we conducted a specific field mission to enroll laboratory-confirmed survivors of the three Gabonese ZEBOV outbreaks.
Biological samples were obtained during a joint field mission between the "Laboratoire d'Ecologie, Systématique et Evolution" and "Centre d'Ecologie et Physiologie Energétiques".
