Massive Delta IV rocket launches from California

Boeing-built Delta IV-Heavy launches today. (VAFB)

A secret military defense satellite for the United States headed into space today aboard the most massive rocket ever launched from the California coast.

The United States' National Reconnaissance Office L-49 satellite is one of the largest payloads to be placed into a polar orbit around earth, and will serve as both an early warning platform for incoming foreign threats and to observe known hostile regions.

This flight marked the first space shot of the new year for the United States and the second worldwide.

A United Launch Alliance Delta IV-Heavy rocket's three liquid-fueled rocket boosters ignited to carry aloft the NROL-49 from launch pad SLC-6 at Vandenberg, AFB, at 4:10:30 pm EST (1:10 pm local) this afternoon.

This fifth flight of a Delta IV-Heavy lifted-off from the south base's space launch complex 6, the same pad which was primed in the mid-1980's for the military's space shuttle launches.

Four previous Delta IV-Heavy's have launched from Cape Canaveral Air Force Station since January 2004.

The countdown got underway at 10:38 am EDT, at the T-5 hour, 15 minute point. A slight two minute delay later occurred during the counts only hold to avoid space junk orbiting earth.

A half-hour later, the launch team began fueling the liquid oxygen tanks of the common booster core. Just over an hour later, the liquid hydrogen fueling started.

The 236-foot tall rocket features three common booster cores with a single engine, each delivering nearly 745,000 pounds of thrust at launch or 2,234,000 pounds combined.

Launch began at T-4 seconds when the three RS-68 engines ignited and throttled to full thrust.

Once the Delta rose into the blue midday sky, the launch became visible around the Los Angeles region to the south as the vehicle darted south and out over the Pacific Ocean.

Just over six minutes into the launch, the twin booster cores emptied their fuel and was jettisoned as the rocket flew nearly parallel with Baja California.

The exact deployment time of the payload will not be disclosed, according to the 30th Space Wing at Vandenberg.

The next Delta IV-H is on the table to fly from Cape Canaveral in December, however two medium size Delta IV's will launch beginning this spring also from the Cape.