East Lyme — The brief period of having all of the state’s Connecticut National Guard units at home is over now that a local unit is headed to Afghanistan.

The 242nd Engineer Detachment (Construction Management Team) was mobilized in support of Operation Enduring Freedom, Maj. Gen. Thaddeus J. Martin, commander of the Connecticut National Guard, announced Thursday. The Niantic-based unit is the first Connecticut Army National Guard unit to deploy in 2014.

A month and a half ago, Martin welcomed home the last unit deployed overseas — the 143rd Combat Sustainment Support Battalion of Waterbury. Sixty-four soldiers spent nine months in Kuwait. It was the first time since March 2003 that all of the Guard units were home.

The detachment of about 10 people left Bradley International Airport Thursday to train at Fort Bliss, Texas. They will spend nine to 12 months in Afghanistan serving as part of an engineer task force that is deconstructing and consolidating coalition operating bases to coincide with the drawdown of combat forces, and training Afghan National Army engineers.

This is the first deployment for the detachment, which specializes in planning, managing and assessing engineer projects and was federally recognized as a unit in 2011. The Guard’s spokesman, Col. John R. Whitford, of Norwich, commands the unit.

“This is an important mission that will facilitate Allied plans to turn over significant base operations responsibilities to the ANA (Afghan National Army) this year,” Martin said in a statement.

Martin has said the number of guardsmen overseas will be low in 2015, which is a reflection of the transition out of Afghanistan. Twelve individual airmen are deployed supporting other units’ missions in Southwest Asia.

j.mcdermott@theday.com