Members of an aerospace union that works on NASA’s space shuttle engine testing program in Mississippi and Alabama have agreed to a new contract.

Local 2249 of the International Association of Machinists and Aerospace Workers voted Monday to accept a contract offer from Jacobs Technology.

The company, a subsidiary of Jacobs Engineering in Pasadena, Calif., holds test operations contracts for work at Stennis Space Center in Hancock County and the Marshall Space Flight Center in Huntsville, Ala.

The union had rejected Jacobs’ first contract offer. Union members voted to strike, but agreed to stay on the job another week as negotiations continued.

Union business representative Joe Harrington said Tuesday that the new contract is for four years and provides total salary increases of 13 percent over the life of the contract.

The union has about 120 members.

Workers perform tasks at Stennis involving propulsion and engine test services, facilities design and other space shuttle-related programs, Harrington said.

The local’s parent union, the IAMA, is headquartered in Maryland.

Jacobs has held contracts with NASA since the mid-1960s.