After a quiet 2006 that saw just two launches and a whole lot of waiting for payloads, the United Launch Alliance Atlas 5 rocket program is preparing for a flurry of flights over the next several months.

Credit: Pat Corkery/Lockheed Martin

Last year began with the successful January dispatch of NASA's New Horizons space probe destined to explore Pluto and the outer reaches of the solar system. A commercial launch of the European ASTRA 1KR television broadcasting satellite followed in April. The Atlas fleet then fell into a lull caused by delays in readying satellites for subsequent flights.

History books will show 2006 as one of the slowest times for Atlas in years.

But 2007 promises to get the new-generation launcher back in action, buoyed by the first wave of missions for the U.S. Air Force.

Atlas 5 was created by Lockheed Martin as part of the military's Evolved Expendable Launch Vehicle program, along with the Boeing-developed Delta 4 rocket family. To date, the Delta 4 has carried out five flights for the Air Force. Now, Atlas 5's initial military mission is about to go up.

The Air Force has targeted a February 22 liftoff from Cape Canaveral to deploy a cluster of experimental satellites. The evening's launch window runs from 9:54 to 11:51 p.m. EST.

The basic version of the Atlas 5 rocket will be utilized, with the 19-story vehicle sporting a four-meter diameter nose cone, no strap-on solid motors and a single-engine Centaur upper stage. This particular version, called the 401 configuration, has flown successfully three times on commercial and NASA science flights.

The Air Force calls the mission Space Test Program 1. Onboard is the Defense Advanced Research Projects Agency's Orbital Express, a two-satellite payload that will demonstrate in-space refueling between the prototype servicing satellite called the Autonomous Space Transfer and Robotic Orbiter, or ASTRO, and the NextSat serviceable spacecraft.

In addition, Atlas will deploy four other satellites from the Evolved Expendable Launch Vehicle Secondary Payload Adapter. The so-called ESPA ring, which is debuting on this launch, enables several small spacecraft to hitch a ride aboard EELV rockets. The satellites picked for this flight opportunity are the STPSat 1 featuring Naval and Air Force Research Laboratory experiments, the Los Alamos National Laboratory's CFESat, the Air Force Academy's FalconSat 3 and the Naval Academy's MidSTAR 1.

The two-stage rocket, known as AV-013, stands assembled inside the Vertical Integration Facility (VIF) near the pad at Cape Canaveral's Complex 41. The satellites are being readied at a processing hangar for their upcoming delivery to the VIF for mounting atop the Atlas. Rollout to the pad typically occurs the day before launch.

The flight has been delayed a couple of times in recent months, slipping the liftoff from last September. Additional testing and ground station software development pushed the launch into 2007. The latest rescheduling moved the flight from mid-January to give teams more time to prepare for Orbital Express' complex on-orbit experiment runs, according to the Air Force.

After the STP 1 mission is delivered to space, the year continues with the Air Force's planned May 4 launch of another Atlas 5-401 vehicle from the Cape. This 10th overall Atlas 5 flight will haul a classified cargo into orbit for the National Reconnaissance Office. That is the government agency responsible for the nation's fleet of spy satellites.

The AV-009 rocket's mission is designated NRO L-30. Given the secretive nature of the payload, nothing has been released publicly about its purpose.

The long-awaited launch of the military's first Wideband Gapfiller Satellite is slated for June 28. The AV-011 vehicle will fly in the 421 vehicle configuration, which is similar to the year's two earlier launches except two solid rocket boosters are attached to the first stage for added thrust at liftoff.

Built by Boeing, the 6.5-ton Wideband Gapfiller Satellite is a sophisticated geostationary communications spacecraft to serve U.S. military forces. The Air Force says this will be the Defense Department's highest capacity communications satellite ever orbited.

Another summer ascent from the Cape follows on August 28 with the commercial launch of the ICO G1 mobile communications satellite. The AV-014 rocket in the 421 configuration will loft the Loral-built payload that is designed for relaying voice and data communications throughout the U.S.

Also on the manifest is the first West Coast Atlas 5 rocket flight from Vandenberg Air Force Base, California. The NRO L-28 mission on the AV-006 vehicle carries a classified payload using the 411 version distinguished by just a single strap-on solid motor. The launch, which slipped out of 2006, doesn't have an assigned date at the moment, Air Force officials said.