Delta 4

ULA’s Delta 4-Heavy rocket still grounded by launch pad problem

United Launch Alliance engineers have resolved the problem that triggered an abort of a planned Delta 4-Heavy rocket launch Sept. 30, but the company said Friday it is continuing to evaluate a concern with the launch pad swing arm retraction system at Cape Canaveral. ULA said the Delta 4-Heavy’s mission to launch a classified National Reconnaissance Office spy satellite will be postponed beyond next week.