Microgravity Repose Angle
In collaboration with NASA Glenn Research Center, Carthage students developed and carried out experiments to measure the repose angle of lunar regolith simulants in vacuum under lunar gravity conditions aboard NASA’s reduced gravity aircraft.
Experiment Background
We further investigated a plausible scaling relationship for the dependence of repose angles on effective gravitational acceleration.
The lunar repose experiment consists of three stainless steel drums with quartz viewing windows. Each drum contains a unique regolith simulant and is rotated at precise rates driven by software-controlled PWM units. The regolith dust climbs the wall of the drum until the dynamic angle of repose is achieved and the pile collapses. Maximum angles are measured as a function of drum rotation speed and the relevant scaling parameter (Froude Number) is calculated. The drums can be evacuated to milliTorr levels to approximate the (harder) vacuum of the lunar surface.
Flight Campaigns
2009 NASA SEED
Student Involvement
Erin Martin, Samantha Kreppel, Bradley Frye, Isa Fritz, Joseph Monegato
Posters and Presentations
Scaling Relationships for Repose Angles of Lunar Mare Simulants
Reports and Publications
Scaling Relations for Repose Angles of Lunar Mare Simulants (Proceedings Abstract)
(Crosby, K. M.; Fritz, I.; Kreppel, S.; Martin, E.; Pennington, C.; Frye, B.; Agui, J.), Annual Meeting of the Lunar Exploration Analysis Group, held November 16-19, 2009 in Houston, Texas.
Repose Angles of Lunar Mare Simulants in Microgravity
(Isa Fritz, ’10; Samantha Kreppel, ’10; Kevin Crosby; Erin Martin, ’09; Caitlin Pennington, ’09; Brad Frye, ’10; Jose Monegato, ’09; and Agui, J.), Proceedings of the 19th Annual Wisconsin Space Grant (2009).