NASA astronaut Suni Williams (seated), assigned to Boeing’s first operational mission aboard the company’s CST-100 Starliner spacecraft, watches as Boeing test teams outfit Starliner with hot plates and radiators ahead of the thermal vacuum test series at Boeing’s Space Environment Test Facility in El Segundo, Calif. NASA’s Commercial Crew Program is working with Boeing to return human spaceflight launches to the space station from U.S. soil.