(AP) — A new U.S. clandestine satellite has rocketed into space.

An unmanned Delta IV-Heavy lifted off Friday morning from Cape Canaveral, Florida. It carried a for the National Reconnaissance Office.

The office is keeping quiet about the satellite's purpose.

This was the second rocket for the NRO in the last two weeks. An Atlas V rocket carrying another secret satellite was launched June 20.

Friday's launch was delayed a day because of concerns about weather conditions caused by Tropical Storm Debby earlier in the week. The launch was delayed three hours for several technical issues with a sticky valve.