WASHINGTON ― On strike since May 7, members of the International Association of Machinists and Aerospace Workers union are returning to work May 22 after accepting a new four-year contract offer from United Launch Alliance over the weekend.

The nearly 600 workers are spread between ULA’s rocket-manufacturing center in Decatur, Alabama, and its two launch facilities in Cape Canaveral, Florida, and Vandenberg Air Force Base in California.

The union rejected the original contract offer because of concerns about extended travel stints for work and subcontracting.

The new contract guarantees workers are exempt from traveling for two weeks after returning from a previous work trip, addressing concerns that employees do not get to spend enough time at home with their families. Additionally, the general annual wage increased from 2 percent over three years to 3 percent over four years.

It also included language guaranteeing subcontractors and salaried employees would only be used in the event of the “unforeseen absence” of union workers.

“We are pleased that the IAM-represented employees have ratified this agreement that is so critical to continuing ULA’s success,” said Tory Bruno, ULA president and CEO. “We believe this contract will help secure our place as the go-to provider for launching people and one-of-a-kind payloads into space well into the future. “