[SatNews] Regardless of the sophistication of all scientific equipment and bright minds involved in a launch, one fact remains...

we're still at the mercy of the weather. Due to the forecast for Tropical Storm Debby, the launch of a Delta IV carrying a national security payload for the National Reconnaissance Office is delayed 24 hours.

The launch is now planned for Friday, June 29 at 6:13 a.m. from Space Launch Complex-37 at Cape Canaveral Air Force Station in Florida. The protective Mobile Service Tower will remain around the launch vehicle and is scheduled to be moved for launch Thursday evening.

Developed in partnership with the U.S. Air Force (USAF) Evolved Expendable Launch Vehicle (EELV) program, the Delta IV family of launch vehicles combines design simplicity, manufacturing efficiency, and streamlined mission and vehicle integration to meet customer requirements to launch high-priority USAF, National Reconnaissance Office (NRO), NASA, and commercial payloads to orbit. With operational launch pads on both coasts—Space Launch Complex-37 at Cape Canaveral Air Force Station, Fla., and Space Launch Complex-6 at Vandenberg Air Force Base, Calif.—every Delta IV configuration is available to service the requirements of current and future satellite programs.

The National Reconnaissance Office's NROL-15 payload, encapsulated in a 5-meter diameter payload fairing, is mated to a Delta IV Heavy rocket in preparation for launch from Space Launch Complex-37.

The Delta IV launch system is available in five configurations: the Delta IV Medium (Delta IV M), three variants of the Delta IV Medium-Plus (Delta IV M+), and the Delta IV Heavy (Delta IV H). Each configuration is comprised of a common booster core (CBC), a cryogenic upper stage and either a 4-m-diameter or 5-m-diameter payload fairing (PLF).

There are three variants of Delta IV M+ configuration. The Delta IV M+(4,2) uses two strap-on solid rocket motors (SRMs) to augment the first-stage CBC and a 4-m diameter PLF. The Delta IV M+(5,2) and Delta IV M+(5,4) have two and four SRMs, respectively and 5-m-diameter PLF.