Last-minute technical problem delays NASA's flight to sun

CAPE CANAVERAL, Fla.— A last-minute technical problem Saturday delayed NASA's unprecedented flight to the sun.The early morning launch countdown was halted with just one minute, 55 seconds remaining, keeping the Delta IV rocket on its pad with the Parker Solar Probe.Rocket maker United Launch Alliance said it would try again Sunday, provided the helium-pressure issue can be resolved quickly. As soon as the red pressure alarm for the gaseous helium system went off, a launch controller order