A second woman has graduated from the Marine Corps' grueling Infantry Officers Course

They once said it was impossible, but now it's been done twice.

A second female Marine officer graduated from the Marines' rigorous Infantry Officers Course at Quantico, Virginia this month, the first to complete the course en route to becoming a ground intelligence officer.

The officer, who has not been identified, graduated from the course June 23, Marine Corps Training and Education Command spokesman Capt. Joshua Pena told Military.com.

The news was first reported by Marine Corps Times.

The officer is now headed to the Ground Intelligence Officer Course at the Navy/Marine Corps Intelligence Training Center in Dam Neck, Virginia. It's a six-week program.

"If she graduates, her 0302 (infantry officer) [military occupational specialty] will become secondary, and 0203 (ground intelligence officer) will become primary," Pena said.

The Marine's accomplishment comes less than a year after a female lieutenant became the first woman to pass IOC in September 2017, making history as she took her place in the previously all-male ranks of Marine Corps infantry officers.

The 13-week course is a prerequisite for both the infantry officer and ground intelligence fields and is notoriously grueling, including lengthy hikes loaded with combat gear, obstacle courses, and mentally rigorous training.

Some 40 female officers have attempted IOC since it was opened to women on an information-gathering basis in 2012. At least two previously have attempted it in hopes of earning a ground intelligence MOS. Female Marines have only had the opportunity to earn an infantry MOS since 2016, when all combat jobs were opened to women as part of a Pentagon-wide initiative.

In another first this month for women in the Marine Corps, Lt. Col. Michelle Macander became the first woman to command a Marine Corps ground combat arms unit when she took command of 1st Combat Engineer Battalion June 22, Marine officials confirmed.