Sample sealing approaches for Mars Sample Return caching

Sealing methods for encapsulating samples in 1 cm diameter thin-walled sample tubes applicable to future proposed Mars Sample Return missions were investigated based on power requirements, operation in the Martian environment, dust tolerance, shock and vibration, maintenance of sample integrity, hermeticity, packaging requirements, mission risk, and ability for autonomy. Techniques implemented include a spring energized Teflon sleeve plug, a crimped tube seal, a heat-activated shape memory alloy plug, a shape memory alloy activated cap, a solder-based plug, and a solder-based cap. Testing will be performed on the prototypes to determine their sensitivity to particle contamination along the sealing surface, Helium leak rate, and survivability over a range of temperatures to help recommend sealing techniques for the proposed Mars Sample Return campaign.