NASA's first Atlas 5 rocket on the West Coast underwent a practice launch day and fueling exercise Tuesday at Vandenberg Air Force Base in California.

The Atlas rocket first stage is erected for the LDCM mission. Credit: NASA/Roy Allison

The United Launch Alliance booster is scheduled for blastoff in February carrying a remote sensing spacecraft known as the Landsat Data Continuity Mission, or LDCM.

The satellite will continue the 40-year legacy of monitoring the Earth's environment from space through the Landsat series of craft. This latest bird, built by Orbital Sciences Corp., is equipped to obtain medium-resolution multispectral digital images of the global land surface, coastal shallows and coral reefs through the Operational Land Imager and the Thermal Infrared Sensor instruments.

LDCM is a collaboration between NASA and the U.S. Geological Survey to further the Landsat data records that began in 1972 with Landsat 1 and five subsequent follow-on satellites over the decades.

To keep supplying that data archive, LCDM was conceived in 2005 and now stands just two months from launch into a 438-mile polar orbit.

The satellite completed its environmental testing on Nov. 23, undergoing rigorous testing inside a thermal vacuum chamber at the Orbital's facility in Gilbert, Arizona. The tests subjected LDCM to the high heat and low temperature swings it will experience in orbit.

Plans call for the satellite to arrive at Vandenberg on Dec. 19, beginning its own launch site campaign before joining up with the Atlas 5 rocket at the Space Launch Complex 3-East pad a couple of weeks before liftoff.

The rocket's on-pad assembly occurred in early October as the bronze first stage with its RD-180 main engine was erected, followed by the interstage adapter and then the white Centaur with the cryogenic RL10 engine.

On Tuesday, crews retracted the mobile service gantry away from the rocket around 8 a.m. local time and began loading the the supercold liquid oxygen and liquid hydrogen around 10:30 a.m. PST.

Clocks counted all the way to T-minus 0 seconds before cutting off as planned, ending the rehearsal at the pretend 1:40 p.m. local launch time.

Called the Wet Dress Rehearsal, the WDR provides the launch team and mission managers with a realistic run-through of the countdown timeline and decision-making calls. It also gives engineers a chance to uncover any technical problems that need resolved before the actual launch attempt.

The launch is dubbed AV-035 in the Atlas lineup. It will follow the Air Force's X-37B deployment flight planned for next week and the late January mission carrying NASA's Tracking and Data Relay K satellite, both of which will originate from Cape Canaveral, Florida.