The U.S. Air Force, Boeing and the National Reconnaissance Office (NRO) are assessing the schedule and hardware implications of potentially significant damage at Cape Canaveral's Launch Complex 37, and perhaps even the Delta IV Heavy rocket on that launch pad, following a dangerous liquid oxygen leak that occurred during a countdown dress rehearsal with the massive vehicle loaded with tons of liquid oxygen and liquid hydrogen.

The Feb. 28 leak could have caused the explosion of the vehicle on the pad, and in this case it damaged the "launch table" steel structure that physically supports the rocket.

The incident already has delayed the planned launch of the final $250 million U.S. Air Force/Northrop-Grumman Defense Support Program (DSP) missile warning satellite that had been planned for April 1. The DSP mission was likely to slip anyway due to less significant processing issues. The spacecraft is not yet atop the launcher, and was in no danger at a processing facility miles away. Likewise, no personnel were in danger.

But the new problem also will likely delay the launch of a massive $1 billion-class NRO eavesdropping spacecraft similar to that used to pick up transmissions from adversaries like Al Qaeda. The NRO eavesdropper, with antennas the size of basketball courts, had also been delayed before, but this will worsen the situation. The NRO eavesdropper satellite is, like the DSP, is to be launched into geosynchronous orbit by a Delta IV heavy.

The Air Force and Boeing are beginning inspections of the rocket and pad, but were delayed from making detailed inspections until March 8, about a week after the incident because of safety concerns and the need to preserve technical evidence that would indicate what actually occurred. The leakage of -300F liquid oxygen caused the pad damage.

"Two structural cracks were observed in the metallic launch table following the Wet Dress Rehearsal," the Air Force said. "An investigative team has been formed to determine the root cause and corrective action."

Possibly involved in the accident is a large plate-like structure integrated with the base of the Delta IV rocket before it is elevated.

As this problem is assessed, the Air Force, the Defense Advanced Research Projects Agency (DARPA), Lockheed Martin and the new United Launch Alliance (ULA) that includes Boeing are pleased with the launch of an Atlas V late March 8 that carried the complex Space Test Program (STP-1) payload with six spacecraft.

"STP-1 required an extraordinary level of coordination and innovation to achieve the mission requirements," said Jim Sponnick, ULA vice president of Atlas programs. "One of those innovations was the mission design to achieve the two mission orbits, which was enabled by the development of a very flexible new guidance design. The fact that the Atlas system performed so [well] in delivering the six satellites to their prescribed orbits is a tribute to the teamwork between our Air Force customer, the Space Development & Test Wing, and men and women of the ULA team, including our suppliers from around the world," he said.