Technical issues on Tuesday forced Lockheed Martin officials to postpone the first countdown dress rehearsal for its new Atlas 5 rocket until Wednesday.

The Atlas 5 rocket nears the open-air launch pad at Complex 41 during rollout on Monday. Photo: Lockheed Martin

Plans had called for the towering 191-foot tall rocket to be fully fueled for a countdown simulation at Cape Canaveral Air Force Station's Complex 41 on Tuesday, but glitches prompted workers to be dispatched to the oceanside pad for troubleshooting.

A company spokeswoman said in the end time simply ran out to conduct the entire rehearsal Tuesday.

Assuming the countdown test is conducted successfully on Wednesday, the rocket will be safed and then rolled back to its assembly building on Thursday atop a mobile launching platform.

Known as a Wet Dress Rehearsal, or WDR, three of these countdown tests are planned over the next couple of months as pathfinder exercises to practice transporting the rocket to the pad, loading propellants and conducting simulated launch days for the control team.

The tests give engineers the chance to find any problems early so they can be resolved before the real launch day arrives.

This first Atlas 5 rocket, tail-number AV-001, will fly in what Lockheed Martin calls the 401-vehicle configuration. That means it will have a four-meter payload fairing nose cone, no strap-on solid rocket boosters and one engine on the Centaur upper stage. As with all Atlas 5 configurations, the first stage is made up of a "Common Core Booster" powered by a Russian RD-180 engine.

Launch of the maiden Atlas 5 is targeted for no sooner than June carrying the Hot Bird 6 direct broadcasting satellite for Eutelsat.

The inaugural Atlas 5 will be the largest Atlas rocket ever to fly. Photo: Lockheed Martin