Composite mate joint passes tests for Composite Crew Module

Northrop Grumman developed a unique joint design that was used to mate two segments of NASA's Composite Crew Module demonstrator.

Northrop Grumman Corp. (El Segundo, Calif., USA) announced on Dec. 17 that a method it implemented for joining composite structures on the Composite Crew Module (CCM) has passed a series of intensive structural tests, paving the way for the use of composites in future spacecraft.

"This is a major step forward for the use of composites infuture missions," said Gene Fraser, vice president of Advanced Programs and Technology for Northrop Grumman Aerospace Systems. "Our engineering and technology development efforts on this composite structure will enable future manned habitats for the Moon and beyond."

In collaboration with the NASA Engineering and Safety Center (NESC) Composite Crew Module team, Northrop Grumman developed a unique joint design that was used to mate two segments of NASA's CCM demonstrator. The joint design test results proved that the mating process retains compartment pressure and withstands external loads at twice the level normally experienced in flight. In addition, the new process provides mass and cost savings due to the elimination of mate joint fasteners, more efficient subsystems installation and no requirement for an autoclave during mate. The CCM is a high-fidelity technology demonstration article that represents the inner pressurized shell for the Orion crew module.

"The splice region performed exactly as our analysis predicted," said Mike Kirsch, NASA CCM program manager. "We tracked the strain across the joint and verified that the non-autoclave cured composite was fully capable of handling the pressure and vehicle loads in the crew cabin."

Conducted at the NASA Langley Research Center in Hampton, Va., the Northrop Grumman team also installed an advanced fiberoptic strain-sensing system on the CCM, which monitored more than 3,500 channels of data in real time during the test to monitor the splice joint's performance. Additional tests measured the CCM's performance during ultimate loads for launch, on-orbit, and abort scenarios. NASA is now proceeding with post-impact load conditions to verify the robust residual strength characteristics of the CCM habitat structure. The test program will be complete in spring 2010.

In recognition of the company's participation in the CCM splice fabrication effort, NESC, which is leading development of the CCM, presented Northrop Grumman's engineer Dawson Vincent with a Technical Excellence Award in October.