NanoRocks: Design and Performance of an Experiment Studying Planet Formation on the International Space Station

Abstract

In an effort to better understand the early stages of planet formation, we have developed a 1.5U payload that flew on the International Space Station (ISS) in the NanoRacks NanoLab facility between September 2014 and March 2016. This payload, named NanoRocks, ran a particle collision experiment under long-term microgravity conditions. The objectives of the experiment were (a) to observe collisions between mm-sized particles at relative velocities of $<$1~cm/s, and (b) to study the formation and disruption of particle clusters for different particle types and collision velocities. Four types of particles were used: mm-sized acrylic, glass, and copper beads, and 0.75 mm-sized JSC-1 lunar regolith simulant grains. The particles were placed in sample cells carved out of an aluminum tray. This tray was attached to one side of the payload casing with three springs. Every 60~s, the tray was agitated and the resulting collisions between the particles in the sample cells were recorded by the experiment camera. During the 18 months the payload stayed on ISS, we obtained 158 videos, thus recording a great number of collisions. The average particle velocities in the sample cells after each shaking event were around 1 cm/s. After shaking stopped, the inter-particle collisions damped the particle kinetic energy in less than 20~s, reducing the average particle velocity to below 1 mm/s, and eventually slowing them to below our detection threshold. As the particle velocity decreased, we observed the transition from bouncing to sticking collisions. We recorded the formation of particle clusters at the end of each experiment run. This paper describes the design and performance of the NanoRocks ISS payload.

arXiv comment8 pages, 8 figures

References in corpus (8)

• The outcome of protoplanetary dust growth: pebbles, boulders, or planetesimals? II. Introducing the bouncing barrier
• Accretion Disks Around Young Objects. III. Grain Growth
• A 10 micron spectroscopic survey of Herbig Ae star disks: grain growth and crystallization
• Millimeter Emission Structure in the first ALMA Image of the AU Mic Debris Disk
• The Physics of Protoplanetesimal Dust Agglomerates. IV. Towards a Dynamical Collision Model
• Free Collisions in a Microgravity Many-Particle Experiment III: The Collision Behavior of sub-Millimeter-Sized Dust Aggregates
• Submillimetre-sized dust aggregate collision and growth properties
• Low-velocity collision behaviour of clusters composed of sub-mm sized dust aggregates

Cited by in corpus (5)

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• Multi-Particle Collisions in Microgravity: Coefficient of Restitution and Sticking Threshold for Systems of Mm-Sized Particles
• Selective Aggregation Experiments on Planetesimal Formation and Mercury-Like Planets
• Future Exoplanet Research: Science Questions and How to Address Them