The Boeing Company is beginning an exhaustive review of testing records and data that will determine when the inaugural Delta 4-Heavy rocket will be given clearance for blastoff from Cape Canaveral, Florida.

Boeing is working to firm up the planned launch date of its first Delta 4-Heavy. Photo: Carleton Bailie/Boeing

The launch team conducted the last planned countdown dress rehearsal Tuesday at Complex 37 in which the massive rocket was fueled to simulate an actual liftoff attempt. The test was designed to uncover any problems while providing engineers valuable practice handling the complicated vehicle.

"We go down to T-0, do everything but light the rocket and let it go," Delta program manager Dan Collins told reporters during a news briefing at the Delta 4 Operations Center where the launch team controls the countdown.

Developed in the late 1990s for the Air Force's Evolved Expendable Launch Vehicle program, which is aimed at reducing rocket costs and improving reliability, Boeing's Delta 4 family has flown three times. Those successful missions in 2002 and 2003 used medium-lift rockets with a single Common Booster Core first stage and a cryogenic upper stage. In this upcoming Delta 4-Heavy launch, three Common Booster Core stages are strapped together to form a triple-body rocket capable of hauling hefty payloads into orbit.

The Air Force is paying Boeing in excess of $150 million to launch the debut Delta 4-Heavy on a demonstration flight. The rocket will carry a 13,000-pound instrumented satellite mockup and a pair of tiny university nanosatellites. The mission's goal is proving the vehicle works correctly before critical military spacecraft begin flying on Delta 4-Heavy rockets starting next year.

"This booster is critical for our nation's security because it will enable us to launch our heaviest DoD and national reconnaissance satellites after Titan 4 retires," said Lt. Col. Robert Atkins, commander of the 5th Space Launch Squadron that oversees EELV missions at Cape Canaveral.

What's more, Boeing executives want a successful inaugural launch to bolster the Delta 4's reputation as NASA examines heavy-lift vehicles for its new space exploration initiatives.

Boeing delivered the rocket to pad 37B last December for the extended-duration stay on the seaside complex to conduct a series of tests and simulations. Officials are eyeing a launch date of November 18, but there is a possibility the mission could slip into early December depending on the outcome of the data review process now starting.

"From here we really go into a lot of reviews," Collins said Tuesday. "We sit and take a very, very hard look at all of the data we have come up with since we started developing the rocket, the (qualification) test plans and what our mission is here."

Collins said engineers and senior managers alike will be asking themselves: "Have we thought of everything? Are we ready to go?"

"If at any point in that process the answer comes up 'no,' then we are going to reassess and we're going to make sure we that we've done everything. And that goes for the entire supply chain on the rocket -- from, obviously, the propulsion providers to anyone else who is involved in this rocket. If at any time they see a reason that they've got concern, we are going to stop, evaluate it and make sure that when we do get launch day that we are ready for mission success."

The Delta 4-Heavy rocket has been on the launch pad since last December. Credit: Boeing photo by Carleton Bailie

For the past 11 months while the rocket has been on the pad, the team has collected immeasurable amounts of information.

"The first thing we do when we get out to the pad is we run through electrical testing and make sure the ground system and the rocket are talking to each other, communicating well, and all of the electrical systems are going," Collins explained.

Then the rocket fuel began flowing.

"We've taken an incremental approach to the tanking tests. Once we made sure all of the communication and electrical systems are working well, we started putting propellants on the vehicle. The first time we do this we just try to get propellants on the vehicle. There is a well thought-out procedure for it and this is our attempt is to make that procedure really makes sense as you actually put the people into the system and have the propellants flowing. We learned a lot."

That first fueling exercise on April 9 pumped super-cold liquid hydrogen and liquid oxygen into the rocket stages but avoided placing a timeline script on the launch team.

"We take everything we learn and update the procedure and we come into tanking test No. 2 and we verify that what we are doing is right," Collins said. That event occurred May 20.

"Once we have gotten through that one, we then bring in the element of a timeline. That's Wet Dress Rehearsal No. 1," Collins said.

WDR No. 1 on July 21 put the team through a full rehearsal of launch day activities. Wet Dress Rehearsal No. 2 took place Tuesday to demonstrate the proper procedures and timelines are in place to ready the rocket for liftoff at the opening of its launch window.

"It's a building up in steps, letting the team get comfortable with tanking three different Common Booster Cores, getting them thermally conditioned, so that at the front of the window we could push the button and let the rocket go."

Although officials may opt to delay launch to offer more time to digest the facts and data, liftoff is currently targeted to occur November 18 at 2:28 p.m. EST (1928 GMT). A three-hour launch window is available that day, extending to sunset.

"This rocket will launch on the day it is ready. We are baselined on the 18th and working hard to make that happen," Collins said.