FORT STEWART, Ga. -- Standing just over 5 feet, Army Spc. Karen Arvizu is barely a foot taller than the anti-tank missile she carries in both arms and loads into an armored vehicle. She stands on her tiptoes to wrestle open the 300-pound top hatch.
"I have to step on the seat to get the missile into the launcher," said Arvizu, a 24-year-old soldier from Los Angeles. "It's half my body weight."
Arvizu typically drives Humvees or transport trucks at Fort Stewart in Georgia, but for the past three weeks, she and 59 other women soldiers have been getting a taste of what it takes to serve in combat. By spending their days lifting 65-pound missiles and .50-caliber machine guns, all while wearing 70 pounds of body armor, they're helping make history as part of an Army study that will determine how all soldiers -- including women, for the first time -- will be deemed fit to join the front lines.
The Pentagon ordered last year that women must have the same opportunities to serve in combat jobs as men, with thousands of positions slated to open to both genders in 2016. And while an Army survey shows only a small fraction of women say they want to move into combat jobs, it also revealed soldiers from both genders are nervous about the change.
With roughly one in five Army positions considered combat-related, commanders are turning to science to find a unisex standard to judge which soldiers physically have the right stuff to fight wars.
Testing at Fort Stewart and other U.S. bases is breaking away from the Army's longtime standards for physical fitness -- pushups, situps and 2-mile runs -- to focus instead on battlefield tasks, such as dragging a wounded comrade to safety or installing and removing the heavy barrel of the 25 mm gun mounted on Bradley vehicles.
David Brinkley, deputy chief of staff for operations at the Army's Training and Doctrine Command at Fort Eustis in Virginia, said some people think the Army is coming up with unrealistic requirements while others believe standards will be lower to let women fight on the front lines.
"We intend to do neither. That's why we based this on the actual thing you have to do," he said.
At Fort Stewart, a volunteer group of soldiers -- 100 men and 60 women -- are spending a month drilling on the most physically challenging tasks demanded of infantrymen, cavalry scouts, mortar launchers and tank crews. In March, scientists from the Army's Research Institute for Environmental Medicine will have the troops perform those tasks while wearing heart rate monitors, masks that monitor oxygen intake and other equipment to study the effects of their physical exertion.
One of the volunteers, Spc. Artrice Scott, said she has no intention of trading in her job as an Army cook to join an infantry platoon or an armor unit. But she sees the testing as a great opportunity to lead the way for women in the U.S. military.
"The heaviest thing we lift in the kitchen is boxes of frozen chicken, 45 pounds," said Scott, 29, of Mobile, Ala. "And you don't have to lift those over your head."
During a training session Tuesday, Scott shaved 45 seconds off her previous best time carrying two anti-tank missiles into a Bradley armored vehicle and loading them into the turret.
Army commanders say there are no doubts that women have the mental and technical abilities needed. Only their ability to perform the most arduous physical tasks has been questioned.
The survey released Tuesday found there were nagging stereotypes. Male soldiers fretted that their unit's readiness will be degraded because of what they term "women issues," such as pregnancy and menstrual cycles. Or they worried that women incapable of the physical demands would be brought in anyway.
However, the survey also showed that only about 8 percent of Army women said they wanted combat jobs. Brinkley said such limited interest also is in line with what other countries, such as Norway, have seen as they integrated women into combat roles.
Maj. Gen. Mike Murray, commanding general at Fort Stewart, watched Tuesday as coed groups of soldiers set up heavy 120 mm mortars on a practice field. An officer with 32 years of infantry experience, Murray said it's time to open combat jobs to women and "this is going to get studied to death" in order for the Army to prove to naysayers that women soldiers are physically capable. The volunteer group at Fort Stewart includes a mix of combat veterans and newcomers, but it didn't take long for the group to jell after some initial awkwardness.
"It was almost like a high school dance where you had the guys over here and the girls over there," Murray said. "A week later, it was amazing how fast teams form."
Giving soldiers a month to prepare meant women who have never been trained to scale a 6-foot wall or pull a casualty from a tank have had time to learn the proper techniques before they are tested for real next month.
Staff Sgt. Terry Kemp, a cavalry scout who's helping train the Fort Stewart volunteers, said female soldiers started to catch up with their male counterparts after two weeks of training. Missile toting drills that initially took the men seven minutes were taking women 12 minutes to complete, he said. But by week three, men and women had trimmed their times to about four minutes.
Those who still insist women can't perform as well as men in combat "can beat their chests about it all day," said Kemp, a veteran of Iraq and Afghanistan. "But eventually it's going to happen."
Exactly what sort of fitness tests or standards will come out of the Army's study remains to be seen. There are no current fitness requirements for serving in combat positions beyond the Army's standard physical fitness test for all soldiers -- which includes pushups, situps and a 2-mile run and grades men and women on different scales.
Brinkley said the Army took a lesson from fire departments by not focusing on soldier's ability to perform pushups or pullups, which favor men because they test upper body strength. He said officials realize women do physical tasks differently, using more core strength and legs. By focusing on tasks rather than exercises, Army officials hope to eliminate gender bias from their study.
Taking a break from toting anti-tank missiles at Fort Stewart, Arvizu said she found the heavy lifting to be humbling. And though she felt encouraged by her male colleagues, she had no desire to give up driving a truck and join a combat unit.
"It's not that I came, I saw and conquered," she said. "But I came, I saw and I did my best."