Preliminary Advanced Colloids Experiment - 2: 3D Particle Test (PACE-2) - 07.15.14
ISS Science for Everyone
Science Objectives for Everyone Preliminary Advanced Colloids Experiment - 2 (PACE-2) characterizes the resolution of the high magnification colloid experiments with the Light Microscopy Module (LMM) to determine the minimum size of the particles that can be resolved by the Advanced Colloids Experiment (ACE). There is a direct relationship between magnification, particle size, test duration and on-orbit vibration that is quantified.
Science Results for Everyone
ZIN Technologies Incorporated, Cleveland, OH, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
March 2011 - May 2012
Previous ISS Missions
ISS Expedtion 25/26 is the first operation of PACE-2 in microgravity. PACE-1, the precursor to PACE began operation in ISS Expedition 23/24.
- Preliminary Advanced Colloids Experiment - 2 (PACE-2) determines what magnifications can be used with oil immersion microscope objectives for a variety of colloidal particle sizes in the ISS vibration environment.
- This study is a continuation of PACE and provides an additional level of detail for the magnification power of the Light Microscopy Module (LMM) on the ISS.
While the Preliminary Advanced Colloids Experiment (PACE) looks at the gross effects of vibration on a static test target and how this impacts resolution, PACE-2 follows up on this work by looking at a three-dimesional sample in a sample container that is comparable to what will be used by the Advanced Colloids Experiment (ACE). This work also aids in the development and optimization of crew procedures for the future ACE investigation.
The test images will be taken both with the Active Rack Isolation System (ARIS) turned on and with it turned off. The results of the tests determines the size of colloidal particles that can be resolved by ACE and what size particles need to be used for the experiments that have been proposed for ACE.
The knowledge from PACE-2 and PACE will enable ACE. ACE will fly samples that may have an important impact on our understanding of fundamental physics. An immediate space application for this technology demonstration is in extending the shelf-life of consumables on future long-duration missions.
PACE-2 enables ACE, which later will provide important data that is not available on Earth. This data guides our understanding of phase separation (e.g., shelf-life, product collapse), and how it competes with crystallization and impacts production. Additionally, product shelf-life may be dependent upon binodal decomposition and possibly upon Oswald ripening in the emulsion samples. It is for this reason that a better understanding of these processes could have an enormous commercial impact in a wide variety of industries.
This technology demonstration requires that an ISS crewmember set up the hardware in LMM Auxiliary Fluids Container. The crewmember photoexcites fluorescently labeled micron-sized beads in order to observe different particle sizes. Ground teams then command the LMM to acquire the images of the test target. Image acquisition is conducted during crew wake, sleep, and exercise with the FIR Active Rack Isolation System (ARIS) active and disabled.
Nine sessions are planned for a total of 14 hours of crew time.
- Session 1 - Install oil objectives, test sample, inject immersion oil.
- Session 2 - Initiate test sample operations during wake, sleep and exercise periods for 63x oil immersion objective without ARIS activated.
- Session 3 - Change to 100x oil immersion objective, inject oil.
- Session 4 - Initiate test sample operations during wake, sleep and exercise periods for 100x oil immersion objective without ARIS activated.
- Session 5 - Activate ARIS.
- Session 6 - Initiate test sample operations during wake, sleep and exercise for 100x oil immersion objective with ARIS activated.
- Session 7 - Change to 63x oil immersion objective, inject oil.
- Session 8 - Initiate test sample operations during wake, sleep and exercise for 63x oil immersion objective with ARIS activated.
- Session 9 - Clean-up, stow, shut down the LMM.
ISS Research Project-PACE-2
Design rendering of PACE-2 with oil dispensing syringe installed in LMM
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PACE module with pipette and test target as used in PACE-2. Image provided courtesy of Glenn Research Center.
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