Returning Martian samples to Earth for extensive analysis is of great interest to planetary science community. Current Mars sample return architecture would require leaving the acquired samples on Mars for several years before being retrieved by subsequent mission. Each sample would be sealed securely to keep its integrity. A reliable seal technique that does not affect the integrity of the samples and uses simple low-mass tool is required. The shape memory alloy (SMA) seal technique is a promising candidate. The performances of several primary designs of SMA seal for sample tubes were analyzed by finite element (FE) modeling. The results of thermal heating characteristics had been reported in a previous presentation this paper focus on the preparation and actuation of SMA plugs, the seal pressure, and the stress and strain induced in the sealing procedure with various designs.
Several NASA rovers and landers have been on Mars and performed successful in-situ exploration. Returning Martian samples to Earth for extensive analysis is of great interest to the planetary science community. Current Mars sample return architecture would require leaving the acquired samples on Mars for years before being retrieved by subsequent mission. Each sample would be sealed securely to keep its integrity. A reliable seal technique that does not affect the integrity of the samples and uses a simple low-mass tool is required. The shape memory alloy (SMA) seal technique is a promising candidate. A study of the thermal performances of several primary designs of a SMA seal for sample tubes by finite element (FE) simulation are presented in this paper. The results show sealing the sample tube by SMA plugs and controlling the sample temperature below the allowed temperature level are feasible.
A launchable and retrievable tetherbot exploration system for low-gravity environments is proposed where a small,
tethered robot is launched from a base lander or vehicle to a desired position up to 50 m away. When its exploration
mission is complete, it hops vertically above the surface and is simultaneously reeled back in by the base vehicle while
still above ground. Benefits include the ability to traverse long distances in short amounts of time and minimal energy
expense independent of terrain roughness. This technique has the capability to reach locations too difficult, too
dangerous, or unreachable by the base vehicle. Prototypes of a steerable six-legged hopping robot and electric reel were
developed. A dynamic simulation demonstrated the capabilities of launching and tether retrieval.
A prototype of a steerable six-legged hopping robot for exploring low-gravity environments was designed, built, and
tested. A 35 cm vertical hop was achieved, motorized steering of all six legs was demonstrated over a 40-degree range,
and angled hopping was performed at a fixed 60-degree angle. Gyro stabilization was demonstrated through a hopping
simulation of a modeled hopping robot with a controllable flywheel in lunar gravity.
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