U.S. Marines and Army SOF conduct barrel drops and tandem jumps out of a KC-130J at Yuma Proving Grounds on February 9, 2021. This training teaches them how to jump with personnel or equipment in order to expand their mission capabilities.(U.S. Marine Corps photo by LCpl. Gabrielle Sanders) - U.S. Marines and Army SOF conduct barrel drops and tandem jumps out of a KC-130J at Yuma Proving Grounds on February 9, 2021.