Seeking: Inspection Tech for Additive Manufacturing in Space

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NASA is seeking innovative material inspection solutions, including nondestructive evaluation (NDE) and in-situ process monitoring for additive manufacturing for implementation on the ISS and, potentially, in other in-space environments. Solutions should be capable of inspecting parts produced by wire+arc additive manufacturing and/or bound metal deposition with minimal crew interaction required for operation and interpretation. The inspections should characterize surface (external) and/or volumetric (internal) defects to enable certification of parts produced onboard the ISS.

Background

“Make It, Don’t Take It” is the mantra behind NASA’s In-Space Manufacturing project. Due to the high costs and technical challenges associated with each additional kilogram of launch mass, it’s crucial to reduce launch mass required for logistics on future long duration missions where cargo resupply opportunities will be more limited. On-demand manufacturing in space can reduce the need to launch spare parts to ensure mission success. Packaging material and decommissioned parts, which are currently discarded as “trash footballs” on return missions, can be repurposed if they are intentionally designed to be recycled into new feedstock material. In-situ resource utilization can enable the collection, preparation, and use of extraterrestrial materials in manufacturing. At the core of producing functional parts in the space environment is the need for nondestructive evaluation of part quality. Nondestructive evaluation (NDE) includes surface and volumetric inspection to screen for defects such as cracks, voids, and foreign inclusions in the finished part.

Constraints

Required

Must be safe for use in a crewed environment.
Must result in quantitative information about anomaly size and location.
Must be able to inspect a part with complex geometry and a size of up to 6″ in any dimension.
Metal part inspections are of high interest for certification, but inspections for polymers will also be considered

Desired

100% inspection capability of the exterior surface and interior volume of an additive manufactured part would be the ideal outcome.
Spatial resolution of 0.01″ or smaller is desired.
All identified technologies must be compatible with the size, weight, and power requirements of an ISS Express Rack.
Scalability of NDE techniques should be considered, as there are other applications involving large-scale structures that will also benefit from the use of inspection technologies, potentially in the space environment or on a lunar or planetary surface.

Automated, non-contact methods are preferred. These methods would minimize crew time and training, enable remote or closed-loop interpretation and decision making, and not affect the surface of the part or require cleaning.

Possible Solution Areas

Included, but not limited to:

In-situ process monitoring methods including visual, thermal, acoustic, ultrasonic, or electromagnetic inspection.
X-ray computed tomography (CT).
Computer vision/Artificial Intelligence.