The Fluids Integrated Rack (FIR), located in the US Laboratory Module (Destiny), enables investigators from multiple disciplines a large, optics bench platform to integrate a large “mini-facilities” or configuration of optical components similar to their experiment in their ground laboratories. Developed by NASA’s Glenn Research Center, the FIR was launched to the International Space Station (ISS) in August 2009 by the Space Shuttle (STS-128).
The Fluids Integrated Rack accommodates experiments that address critical space exploration research and technology needs for advanced life support (i.e., air revitalization, water reclamation, etc.), power, propulsion, and spacecraft thermal control systems. The primary focus of the these experiments involve boiling heat transfer, multiphase flow, liquid vapor interface control, and liquid and vapor evaporation and condensation, as they relate to the technology needs of various exploration spacecraft subsystems. Another key area of research is in the area of colloids to better understand the interaction of particles and their impact on products produced on Earth. The FIR can also serve as a platform for experiments that address human health and performance, medical technologies, and biosciences.
The Fluids Integrated Rack (FIR) features a large user-configurable volume for experiments. The volume resembles a laboratory optics bench. An experiment can be built up on the bench from components, or it can be attached as a self-contained package, or a combination. The FIR provides data acquisition and control, sensor interfaces, laser and white light sources, power, cooling, and other resources. Astronauts typically mount the investigation equipment and/or test cells and the experiment is operated by ground commands from GRC’s ISS Payload Operations Center (ISSPOC) or from the Principal Investigator (PI) home institution.
The FIR hardware is mounted in an International Standard Payload Rack (ISPR), with an Active Rack Isolation System (ARIS), that provides the supporting elements for the FIR subsystems and mechanical connections to the US Laboratory Module. The ARIS enhances the microgravity environment for experiments in the FIR by attenuating on-orbit vibrations transmitted from the Destiny Module to the FIR. The centerpiece of the FIR structural sub-system is the optics bench. The optics bench provides a mounting surface for FIR light sources and avionics packages on the back of the bench and for payload hardware on the front of the bench. The optics bench can translate out of the ISPR volume and rotate to allow access to the back of the bench. Depending on the use of the FIR diagnostics, the optics bench can accommodate up to 250 kg of payload hardware. The environmental subsystem utilizes air and water to remove heat generated by the FIR and payload hardware. The Electrical Power Control Unit (EPCU) is the heart of the electrical subsystem. All power from ISS flows through the EPCU. The EPCU provides power management and control functions, as well as fault protection. Payload hardware has access to 120 VDC (up to 1400 W) and 28 VDC (up to 672 W) of power from the EPCU. The FIR provides payloads with access to the ISS gaseous nitrogen and vacuum systems through the gas interface subsystem. These systems are available to support experiment operations such as the purging of experimental test cells and pressurizing or creating flows within experimental test cells. The FIR Command and Data Management Subsystem (CDMS) provides command and data handling for both facility and payload hardware. The main components of the FIR CDMS are the Input Output Processor(main command and control computer), the Image Processing and Storage Unit (interface with digital cameras), and the Fluids Science Avionics Package (additional control and data acquisition capability for the payloads). In addition, the CMDS can support real-time image analysis as well as post-processing data capabilities.
The first “mini-facility” that was developed and integrated in the FIR is the Light Microscopy Module. (LMM). The LMM was flown to the ISS on the same Space Shuttle flight as FIR and installed in January 2009. The LMM flight unit features a modified commercial laboratory Leica RXA microscope configured to operate in an automated mode with interaction from the ground support staff. Its core capabilities include a level of containment, white light imaging, fluorescence, confocal microscopy (to be available in 2017), and digital imaging capability. The LMM can accommodate dry and oil immersion lenses (2.5X to 100X). The LMM gives scientists the ability to study—in real time—the effects of the space environment on physics and biology. Specimens can be studied without the need to return the samples to Earth.
The first FIR investigation (2009) in the LMM was the Constrained Vapor Bubble (CVB) experiment. The CVB experiment provided an understanding of two-phase heat transfer systems controlled by interfacial phenomena under microgravity conditions. The first CVB experiment provided very promising results and thus, a second series of experiments were performed on similar experiment cells in 2013. Results of this study will be applicable to the development of wickless heat pipe heat exchanger technology that can be utilized in the spacecraft. Wickless heat pipes provide for a more reliable heat exchanger because there are no moving parts.
The next series of experiments characterized the capabilities of the LMM to perform high magnification with oil immersion lenses in the FIR and calibration of the supporting ARIS system.
The first Advanced Colloids Experiment (ACE), designated the ACE-M-1 experiment, was the first in a series of microscopic imaging investigations of materials which contain small colloidal particles, which have the specific characteristic of remaining evenly dispersed and distributed within the material. The investigation utilized the advantage of the unique environment onboard the ISS in order to separate the effects induced by Earth’s gravity in order to examine flow characteristics and the evolution and ordering effects within these colloidal materials. Engineering, manipulation and the fundamental understanding of materials of this nature potentially enhances our ability to produce, store, and manipulate materials which rely on similar physical properties.
The LMM was utilized to assist in performing on-orbit imaging the roots of Arabidopsis thalianan seedlings as part of the Characterizing Arabidopsis Root Attractions (CARA) experiment. The experiment specific focused on how a root knows which direction to grow in when gravity is absent.
Future investigations with the FIR include the following:
Light Microscopy Module experiments (2014-2020):
LMM/Advanced Colloid Experiments – A series of experiments (16 different experiments planned from 2014-2020) to observe colloid suspensions and processes. This is a continuation of the past ACE-M experiments performed in the LMM. The ACE series will transition from microscopic observations (ACE-M) to microscopic observations with controlled processes (ACE-T, ACE-H) with an eventual series of particle manipulation of the processes (ACE-E). To perform some of these investigations will involve the incorporation of a Confocal unit to the LMM and the enhancement of the imaging capability currently provided
ACE-M provides epi-illumination and basic fluorescence microscopy.
ACE-H provides simple temperature control which causes particles that change size with temperature to form structures.
ACE-T provides quantitative temperature control and temperature gradients.
ACE-E uses electric fields to construct and understand how to construct structured materials and devices.
LMM/Macromolecular Biophysics (MMB) – 2016/2019
The Macromolecular Biophysics (MMB) series of investigations in the LMM will protein crystal growth experiments that will first examine frozen samples to observe the quality of the crystals and later study the formulation of the protein crystals.
Flow Boiling and Condensation Experiment (FBCE) – 2018
A new FIR “mini-facility” that will focus on obtaining critical data for two-phase fluid flow behavior and heat transfer data in microgravity. The experiment data will help validate, gravity independent, mechanistic models for microgravity annular flow condensation and flow boiling critical heat flux. The data will help provide significant savings in power and mass for two-phase thermal systems for future spacecraft.
Contacts at NASA Glenn Research Center
Project Manager: Robert Corban, NASA GRC