The Laplace Experiment: A Facility for Investigating the Initial Stage of Planet Formation

The Laplace facility is an advanced microgravity setup scheduled for launch in fall 2025 and will be installed on the International Space Station (ISS) to explore the initial stages of planet formation. Building upon the insights gained from its predecessor, ICAPS, which was launched aboard the Texus-56 and Texus-58 sounding rockets in 2019 and 2023, Laplace aims to shed light on early dust-agglomeration processes in protoplanetary disks.

 

Investigating the initial stages of planet formation necessitates the study of many-particle interactions, involving millions of micrometer-sized particles within a low-density gaseous environment (typically a few tens of Pascals), where Knudsen numbers significantly exceed 1. These conditions require extended observation periods, making microgravity environments essential for such experiments. Both ICAPS and Laplace setups are equipped with advanced mechanisms to actively protect the dust cloud from diffusion losses and other external forces, as well as concentrate the particles using an actively-controllable thermophoretic trap, functioning along all three axes.

 

Concurrently, the dust cloud is accessible to multiple observational instruments. The entire cloud is monitored in three dimensions from two perpendicular overview cameras. Additionally, a dedicated, high-speed long-distance microscope provides non-destructive in-situ analysis of the growing dust aggregates in a central volume of 1 mm² cross-section. An extinction sensor measures light extinction levels throughout the entire cloud. Repeated measurements of individual particle electric charges are performed using controlled DC or AC fields to determine charge distribution and its evolution over time.

 

This presentation will outline the design and methodologies employed by the Laplace setup, detailing its capabilities, calibration processes, and highlight specific data acquired during the ICAPS flights.