Northrop Grumman composite joining technique passes NASA tests

In collaboration with the NASA Engineering and Safety Center (NESC) Composite Crew Module team, Northrop Grumman developed a joint design that was used to join two segments of NASA's Composite Crew Module (CCM) demonstrator.

The Composite Crew Module is a space capsule design that has the potential to reduce the overall weight of future manned launch vehicles. The technology demonstrator represents the inner pressurised shell for the Orion crew module. (See: ATK delivers Composite Crew Module to NASA.)

According to Northrop Grumman, the test results for the joint design prove that the joining process retains compartment pressure and withstands external loads at twice the level normally experienced in flight.

The new joining process also provides weight and cost savings because of the elimination of joint fasteners, more efficient subsystems installation, and no requirement for an autoclave during joining.

"The splice region performed exactly as our analysis predicted," says Mike Kirsch, NASA CCM programme 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."

"This is a major step forward for the use of composites in future missions," adds 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."

Conducted at the NASA Langley Research Center in Hampton, Virginia, USA, the Northrop Grumman team also installed a fibreoptic strain-sensing system on the CCM, to monitor the splice joint's performance during the test.

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 programme will be complete next spring.