Dendritic Crystal Growth in Microgravity

Abstract

This chapter discusses dendritic crystal growth in microgravity, where microgravity is the unique environment created during space flight in free fall along a low-Earth orbit (LEO). If an attempt is made to grow crystal in microgravity, a spectrum of “g-jitter” is encountered, which is random, oscillatory accelerations, and vibrations. G-jitter can influence some crystal growth processes and it arises from the presence of rotating equipment, such as pumps and fans, and from the movement of on board astronauts. The chapter reviews the scientific accomplishments of three space flight crystal growth experiments carried out on board. These experiments address the fundamental questions concerning the dendritic crystal growth. The formation of the dendritic crystals involves the coupling of two different processes: the steady-state propagation of the tip region, accounting for the formation of the main or primary stem, and the time-dependent crystallization of the secondary and tertiary side branches. These processes work together to establish the most obvious length scales of a dendrite.