What is Joni Ernst's history as a member of the U.S. military?

Joni Ernst has been a member of the Reserve Component of the U.S. military for most of her adult life.
She entered the Reserve Officer Training Corps at Iowa State University at age 20, on Aug. 27, 1990, and served in the ROTC until her graduation in May 1992.
She was commissioned as a second lieutenant in the U.S. Army Reserve in 1992, and subsequently was promoted to first lieutenant in 1995 and captain in 1999. She joined the Iowa Army National Guard in 2001, and was promoted to major in 2005 and lieutenant colonel in 2011, according to military records.
As of this May, she will have 25 years of service in the Reserve Component (which includes both the Army Reserves and the Army National Guard), of which 21 will count toward her military retirement, records show.
While serving as commander of the Iowa National Guard's 1168th Transportation Company, Ernst was called to active duty on Feb. 10, 2003, and ultimately was deployed to Kuwait during the Iraq War. Ernst and her unit arrived in Kuwait on April 19, 2003, and remained until April 5, 2004, according to the company's official mobilization and deployment history, which Ernst wrote.
From May through August 2003, Ernst and her unit drove supply convoys into Iraq, ultimately conducting 402 missions comprising 2,091 loads, 10.5 million tons of equipment and 230,728 miles driven. They transported everything from food and clothing to weapons and ammunition to embalming powder and "over $2 billion in paper currency," according to the company history.
The history describes only one threatening incident while the company ran convoys. As the trucks passed through the southeast Iraqi city of Safwan during the return trip of a convoy to Baghdad, several "young Iraqi males" grabbed onto the vehicles and lay down in their path.
"The drivers kept the trucks rolling forward slowly, and just as the Iraqi men were within harm, they rolled to safety," Ernst wrote in the history. "The trucks were able to pass through with no injuries to the soldiers or the local population."
After the company's convoy duties were finished, it performed guard and patrol assignments at Camp Arifjan in Kuwait.
"(Force protection) wasn't always a serious matter," Ernst wrote in the company history. "Often the local Bedouins would find that their sheep or camels had crossed over the berm into Arifjan. Then the Roving Patrol or (Quick Reaction Force) would be called to chase them back over to the waiting herder. Some of the soldiers were even able to test their camel riding skills."
During her years of service, Ernst has been assigned to units in locations across the country — including St. Louis, Alabama, Georgia, South Carolina, Kansas and several locations in Iowa — and has held many duty assignments. She has served, among other roles, as a platoon leader, a real estate officer, a supply officer and battalion commander responsible for overseeing hundreds of soldiers.
Last September, amid her Senate campaign, she was reassigned from a battalion commander position to a logistical officer position at the Iowa National Guard's Joint Force Headquarters in Johnston. On March 1, she was reassigned again and is now serving as a deputy chief of staff at the headquarters.