Spun Microgravity Liquid Experiment (SMiLE)

This project aims to carry out an experimentalinvestigation into the dynamics of droplet production in a reduced gravity environment onboard the International Space Station (ISS). The experiment has been designed
to interface with and occupy a 1U (11cm x 10cm x 10 cm) slot in the nano labs rack provided by NanoRacks. The investigation will focus on clearly identifying the dynamicsof a newly identified drop formation process present in reduced gravity environments (akin to a dripping tap in reduced gravity). The experiment comprises a flow chamber (where the drops are formed and observed), a syringe pump to provide the flow, two control valves, two USB cameras and a microcontroller. The assembly is housed in a rotating drum, allowing the system to be spun and introducing a centrifugal force to separate the fluid from the air in the flow chamber. Flow rate control allows adjustment of fluidic parameters such as Reynolds and Weber number. Cameras monitor the fluid flow into the chamber and provide the principle data output.

Outcomes from this investigation will be the experimental identification of the measure of the chaos present in this system and a refinement of the understanding of the transitions into and out of this flow regime. Applications of this work are relevant to industries that rely on drop on demand processes such as ink-jet, PCB, flexible electronics and genome printing.

There are two partner organisations key to this project;

1. The International Space University (ISU) in France, and
2. NanoRacks in the US.

From these institutions this project has a current team of four academics, one researcher and two undergraduates. However, this project has been running for the past 5 years and has had the prior contribution of three other academics, 2 researchers and 17 undergraduates over this time. Throughout the duration, the project has attracted $110,000 in real terms leveraging approximately a further $255,000 in in-kind contributions.

Due to the compact and complex nature of this experiment, 3D manufacturing techniques are heavily employed to create complex components. The preparation of three versions (two flight models and one engineering model) of the experiment has been completed. Functional testing of the key fluid systems was carried out.

In partnership with CNES and ISU, the SMiLE team was able to test key technologies onboard the Novespace A310 parabolic flights (93 parabolas each 20-25second of 0g). The experiment was tested under of conditions in microgravity and the centrifugal water system was verified. In addition a custom control board based on a Raspberry Pi was developed along with software designed to control the experiment in space. The launch contract was reviewed by Nanoracks and ISU with experiment included in the launch manifest of the SpaceX CRS-11 mission. The project is aiming for a Q4 2016 handover of flight hardware for an expected February 2017 launch and operations.

For futher information regarding this project please get in touch with A/Prof Barnaby Osborne.