United Launch Alliance (ULA) has completed major milestones for the Orion-capable Delta IV launch pad ahead of a planned launch in September 2014.

The aerodynamic windtunnel testing is now complete and critical design review (CDR) finished for needed launch pad modifications.

"We just completed a windtunnel test of that configuration last week, a very solid, very aerodynamically friendly configuration," says George Sowers, ULA's vice president of business development and advanced systems.

The Orion will be topped with an inert launch abort tower to test its aerodynamics and separation from the capsule. During a crewed launch, the armed tower would be ready to fire, rapidly ejecting the capsule away from the rocket in the event of an abort.

"We actually had the critical design review for the modifications we're doing at the launch site about three weeks ago," says Sowers.

The Delta IV Heavy is supposed to launch Lockheed Martin's Orion crewed interplanetary capsule on its first uncrewed test mission, putting the capsule into a highly elliptical orbit, from which it will re-enter Earth's atmosphere at 84% of the speed of a return from a lunar orbit.

Despite the lack of crew aboard, the launch pad will be modified to pump air into the capsule. "We have to provide certain air inside the capsule, certain data. There are some platform modifications to provide data we have to do," says Sowers.

"Essentially, the actual work on the pad is going to occur between two launches, right prior to the [Orion] launch. It will be in the summer of 2014." They will remove the umbilical cord between rocket and pad and "in parallel we'll have built a new one and we'll install that".

The flight will also qualify the Delta Cryogenic Second Stage for use with Orion; the stage will later be adapted to the Space Launch System for its first flight in 2017, launching the Orion on a cislunar orbit.

ULA is also developing its human-rated Atlas, intended to carry Boeing's CST-100 and Sierra Nevada's Dream Chaser, which are crewed commercial spaceflight vehicles.

"We've got a waterfall of preliminary design reviews (PDR) in the spring leading to a system PDR in June," says Sowers. The emergency detection system (EDS) and launch site PDRs (including a crew tower and access arm design) must be completed beforehand. The company recently completed PDR for the Boeing launch vehicle adaptor.

"A lot of the stuff we're doing there is also common to the Sierra Nevada [adaptor] the crew access tower and EDS and other things," notes Sowers. "We're going a little bit slower on Sierra Nevada with the integration, the mission-unique stuff, but we have completed windtunnel testing for them, and we're going at a little bit slower pace regarding the other stuff."

CDR for the human-rated Atlas is planned for May 2014. Once that review is complete, construction can begin.

Source: Flight International