Cape Canaveral's 2013 launch season began taking shape today as technicians started assembling the Atlas 5 rocket for the year's first Space Coast mission -- delivery of a NASA communications satellite into orbit on Jan. 29.

File image of Atlas first stage hoisting operations. Credit: NASA

The United Launch Alliance-made rocket will haul the Tracking and Data Relay Satellite K (TDRS K) to space to reinforce NASA's communications network that routes voice calls, telemetry streams and television signals from the International Space Station, as well as science information from the Hubble Space Telescope and other orbiting spacecraft.

Liftoff is targeted for Jan. 29 during a 40-minute launch window opening at 8:52 p.m. EST (0152 GMT) from the Cape's Complex 41.

Putting the two-stage rocket together got underway this morning as ULA workers brought the bronze-colored first stage to the Vertical Integration Facility for stacking operations.

By late morning, the booster was secured aboard its mobile launcher, anchored on small supports that protrude from the platform. At liftoff, explosive bolts free the rocket and those supports will retract into the platform walls as the vehicle powers its way off the pad on 860,000 pounds of thrust.

Known as the Common Core Booster, the stage was pulled by a semi-truck up the road from the Atlas Spaceflight Operations Center high bay to the 30-story VIF building where workers attached lifting cranes. The 106.6-foot-long stage was rotated vertical, then maneuvered into the building and stood upright on the mobile platform.

The stage is equipped with a dual-nozzle RD-180 main engine that will burn kerosene fuel and supercold liquid oxygen during the initial minutes of flight.

Upcoming will be installation of the interstage adapter that tappers the 12.5-foot diameter first stage to the 10-foot-wide Centaur upper stage.

The cryogenic upper stage will be hoisted atop the interstage tomorrow to complete the basic buildup of the Atlas 5.

Centaur's single RL10 engine, fueled by liquid hydrogen and liquid oxygen, will perform the necessary burns to achieve orbital velocity and then shape the orbit for deployment of TDRS K.

The stage is 41.5 feet in length and also houses the navigation unit that serves as the rocket's guidance brain.

The rocket is known as the 401 configuration of the multi-varient Atlas 5 family, which is tailored with strap-on solid boosters and different sized nose cones to match the cargo's mass and size.

For TDRS K, however, the plain two-stage launcher with no solids will provide ample performance to carry the Boeing-built satellite to orbit.

The spacecraft arrived from the Boeing factory on Dec. 18 and has since undergone preflight electrical testing at the Astrotech processing facility in Titusville. The loading of maneuvering fuel is scheduled for this weekend.

The satellite will be encapsulated in the rocket's nose cone on Jan. 15 in preparation for delivery to the VIF and mounting atop the Centaur on Jan. 17 to finish assembly of the 19-story-tall launcher.

ULA and its customers have opted to delete the countdown dress rehearsals for 401 vehicles at the Cape, condensing the prelaunch timelines for such rockets, except for planetary missions.

Rollout to the launch complex occurs the day before liftoff as the 1.4-million pound platform rides the rail tracks 1,800 feet from the VIF to the pad.

The seven-hour countdown begins at 1:52 p.m. EST on launch day, leading to cryogenic liquid oxygen and liquid hydrogen fueling operations starting at 6:59 p.m. for a planned blastoff at 8:52 p.m. EST, as the launch window opens for the first Atlas launch of the year and the 35th overall since 2002.