The walkway portion of the Crew Access Arm is seen prior to a deluge systems test March 23 at a construction yard near NASA's Kennedy Space Center in Florida. The arm is being tested before being installed on Space Launch Complex 41 Crew Access Tower later this year. It will be used as a bridge by astronauts to board Boeing's CST-100 Starliner spacecraft as it stands on the launch pad atop a United Launch Alliance Atlas V rocket.