Vibratory Plate Compaction of BP-1 and LHS-1 Utilizing the Planetary Automated Compaction Tool (PACT)

The Multifunctional End Effector for Regolith Construction, Acquisition, and Transfer (MEERCAT) is a robotic arm end effector developed by the Swamp Works Granular Mechanics and Regolith Operations (GMRO) lab [1]. This system has several capabilities including excavation, trenching, regolith size screening, compaction, and geotechnical property measurement.

The NASA Tipping Point Project, Mason, led by Redwire Space, in partnership with the Swamp Works GMRO lab, has continued development and refinement of the PACT system’s compaction capabilities, specifically, under the new moniker Planetary Automated Compaction Tool (PACT). A test campaign in ambient laboratory conditions was conducted using Black Point-1 (BP-1) and Lunar Highlands-1 (LHS-1) simulants in the GMRO’s Big Bin test facility utilizing the Excavation Test Stand (ETS) 2-axis gantry. Along with this work a correlation curve was developed to estimate bulk surface compaction based on surface pocket penetrometer readings of penetration force into simulant.

The tests revealed the PACT system to be capable of achieving 80% relative density (%RD) in BP-1 and LHS-1 using a dual-mass excentric mass motor. Testing showed that the Spot compaction method was more capable of compaction at depth (below 51 mm) than the Raster method. Several other conclusions were made including that higher static compaction pressure improved compaction at depth, and that longer surface contact times provided diminishing returns on compaction performance. A correlation between the ambient testing in LHS-1 performed as part of this test campaign and previous work performed in-vacuum conditions using LHS-1 is also shown over a test sample set.