January, 2014 – Final ground simulation testing for imaging the first ISS Arabidopsis experiments with the Light Microscopy Module (LMM).
The PI and Co-PI from the Genetics Institute and Horticultural Sciences at University of Florida Gainesville, of the CASIS experiment “Characterizing Arabidopsis Root Attractions” (CARA) for the ISS National Laboratory supported final ground testing for the upcoming ISS experiment on January 30-31, 2014. They provided the test sample and real time inputs during the final ground simulation of the CARA-PETRI experiment at the GRC ground simulator facility for Light Microscopy Module (LMM). Below is a composite image from the testing showing a root stem expressing a fluorescent protein as it develops and a detailed image of the root tip.
Plant Biology – ISS experiments with University of Florida scientists
Bittersweet memories of orbiter and final countdown
Gail Perusek and Ron Sicker interviewed by WKSU Radio
LMM brings real-time imaging in space
Compiled by BioPhotonics staff
National Public Radio host Robert Siegel speaks with Julie Robinson, International Space Station program scientist, about the Legos, roundworms and squid embryos riding along on the Space Shuttle Endeavour’s last mission to space. The shuttle program is being discontinued. Monday’s launch of Endeavour is the second-to-last space shuttle voyage.
March 28, 2011 – Operations were successfully completed for the 6 samples sent up on ULF-5.
February 2011 – The biological samples for the LMM launched on space shuttle Discovery’s STS-133 mission on Feb. 24. They include eight fixed slides containing yeast; bacteria; a leaf; a fly; a butterfly wing; tissue sections and blood; six containers of live C. elegans worms, an organism biologists commonly study; a typed letter “r” and a piece of fluorescent plastic.
ISS MICROSCOPY CAPABILITIES
AN ADVANCED AUTOMATED MICROSCOPE
Innovative Microscopy Research Capability from Space
Innovation and imagination are all that are required to use the Light Microscopy Module (LMM) as a laboratory microscope to perform research aboard the International Space Station (ISS). The LMM is a remotely controllable, automated microscope that 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.
Microscope Modified for Space Research
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 (available now), fluorescence, confocal microscopy (available in 2016 to 2017), and an imaging capability from a Q-Imaging Retiga 1300 camera.
LMM Supported in the Fluids Integrated Rack
The LMM operates in the Fluids Integrated Rack (FIR), which is located in the U.S. Destiny Laboratory of the ISS. The FIR provides the LMM with the laboratory infrastructure common to most investigations, including an optics bench, temperature control, power control, illumination, imaging and frame capture, data processing, and other resources. The FIR also provides isolation from vibrations on the station to allow for a more stable environment to obtain high-resolution images. The LMM, in conjunction with the FIR, will help fulfill the vision of a true laboratory in space, which is ideal for low-cost payload development.
Critical Research Enabled by LMM
How matter is organized and moves on the microscopic level profoundly affects the macroscopic world. Understanding these processes will help scientists and engineers build more efficient machines and consumer products both on Earth and space applications. A suite of experiments is enabled by the LMM to allow for a detailed characterization of fluids, colloids, two-phase media, and biological samples. In the future, the LMM could be used to assist in maintenance of station crew health, to advance knowledge of the effects of space on biology, and to contribute to long-term mission space exploration.
1. Monochrome camera
3. Auxiliary fluids container—
4. side view
5. Auxiliary fluids container—
6. front view
7. Glove ports
8. LMM control box
9. Equipment transfer module
A modified Leica RXA research imaging light microscope with powerful laser-diagnostic hardware and interfaces.
LMM control box
The LMM control box contains the control avionics for the entire LMM subrack facility
Q-Imaging Retiga 1300 camera
CHARACTERISTICS AND FEATURES
Engineers at NASA Glenn Research Center modified a Leica RXA laboratory-grade microscope by adding 23 micromotors to permit remote control by scientists on the ground and to meet the demands of space flight and crew-tended operations. As such, it contains all of the necessary optical components for use as a fully functional microscope. The microscope can house many different lenses corresponding to magnifications of 2.5, 4, 10, 20, 40, 50, 63 (air), 63 and 100 oil-coupled objectives. Present capabilities include brightfield and epi-illumination microscopy. Future planned capabilities include high-resolution color video microscopy, condenser assembly, confocal microscopy, and possibly laser tweezers.
LMM Control Box (LCB)
The electrical design of the LMM uses parts of the existing electronics of the Leica microscope and supplementary internal and external electronics that support enhanced automation and imaging capabilities. Motors and linear actuators have been added to motorize the manual functions of the Leica microscope. The LCB provides 16 axes of control for stepper motors and 4 axes of control for servo motors.
Two cameras can be mounted on the headpiece of the microscope; one coaxially with the viewing axis of the microscope and one mounted at an angle on the confocal tube assembly. The two cameras employed are identical Q-Imaging Retiga 1300 units. In addition to these two cameras, there is a small surveillance camera that can be mounted inside the AFC (shown on the next page). The surveillance camera has a fixed window size of 640480 pixels/frame. The Q-Imaging 1300 cooled monochrome camera (6.76.7 μm) has a maximum window size of 12801024 pixels/frame. A camera upgrade has been initiated for 2015.
Auxiliary Fluids Container (AFC)
The LMM provides an enclosed work area called the AFC, which is the main work area for sample cell processing and containment for fluids and shatterable materials. The AFC consists of two sealed glove ports, gloves, and an attachment port for the equipment transfer module (ETM) used for transporting experiment samples from stowage to the LMM. The AFC is fastened to the microscope body and sealed to provide a clean working space and one level of containment. Glove ports allow access to the sample area for cleaning before opening the box and experiment sample changeout or reconfiguration. The ETM can be configured to support various experiment modules and is located below the AFC, which has a pass-through for the samples. Materials are thus transferred without the risk of contamination release. The ETM is loaded with experiment modules on the ground and provides contained storage until the samples are utilized in the experiment.
During all testing in the AFC, the experiment sample is always moved relative to the “fixed” objective lens of the microscope. Movement is accomplished by first mounting the sample on the translation stage assembly, which automates the movements in the plane normal to the main axis of the microscope (i.e., in the X-Y plane). Movement along the main axis of the microscope (Z direction) is accomplished through the stage mount, which is connected to a Z-drive mechanism in the body of the microscope. Translation in the X-Y plane is done using motors on the translation stage itself. These motors receive drive signals through the single electrical fitting located at the end of the X-axis housing.
The LMM has the ability to image custom made microscopic slides for biological tests and sample wells containing colloids, along with commercial OptiCells™, which are a unique cell culture format for growing, monitoring, and transporting biological cells. OptiCells™ contain two parallel, gas-permeable, cell culture treated, polystyrene membranes attached to a standard microliter plate-sized frame . Each side has a growth area of 50 cm², total 100 cm² , 75-μm thick membranes, 2 mm apart. A standard petri dish can be used for plant biology investigations.
Biological Sample Cells
Biological samples for the LMM launched on the Space Shuttle Discovery’s STS–133 mission on February 24, 2011, included fixed slides containing yeast, bacteria, a leaf, a fly (Drosophila), a butterfly wing, tissue sections and blood, and six containers of live C. elegans worms. The wing was from “Butterflies in Space” (a previous study that involved students from around the country) that was flown into space in 2009 on STS–129. In addition, some of the worms were descendants of those that survived the Space Shuttle Columbia STS–107 accident. These experiments were operated using OptiCells™ (right) and sample slides (see previous page).
Physical Science Sample Cells
On-going experiments in thermophysics are conducted in the Constrained Vapor Bubble (CVB) sample modules. In development are “specialty cells” that use physical properties (temperature, E-field) to implement specific colloidal science test matrices. The colloidal science specialty cells will have a geometry and complexity similar to that of the CVB sample module. Prototype temperature, electric field, and biology specialty cells are in development.
Pre-Advanced Colloids Experiment (PACE) LED Base
Present operations use a sample module mounted on a PACE light-emitting diode (LED) base. The ACE-M sample module has 15 small wells (1.2 μl) to observe colloid experiments in epi-illumination. The current experiment with Procter & Gamble will test product stability. A planned experiment with the University of Pennsylvania will test temperature sensitive particles. The PACE module will be modified to include a heater for this experiment.
CURRENT DATA AND FUTURE CAPABILITIES
A stage and condenser upgrade is planned for 2015 to provide transillumination and in-situ mixing and standard features such as darkfield and phase contrast microscopy. In-situ mixing allows for the observation of samples shortly after mixing, and for samples to be reinitialized at any time without intervention by the ISS crew. This will be implemented using a commercial off-the-shelf Leica condenser that will be modified for the LMM.
Confocal Microscopy (2016—2017)
Confocal microscopy will be implemented using a 532-nm frequencydoubled Nd:YAG laser, a Nipkow disk confocal scanner, and an 8- to 12-bit digital camera. The scanner will allow up to 24 frames per second of confocal images to be collected by the camera. The crystal’s three-dimensional structure will be reconstructed by assembling the image slices with an image analysis program from which colloidal growth, structure, and dynamics can be determined. The confocal module will be attached and aligned to the side of the LMM and will access the sample through a camera port on the Leica RXA. The microscope’s reflected light turret will contain a reflecting mirror to direct the light to and from the sample.
Flourescent image of Arabidopsis (root) taken during LMM ground testing for CARA/Petri Plant demonstration planned for SpaceX-3 mission
Laser Tweezers (Proposed)
Laser tweezers would be implemented using a system based upon a laser, beam-focusing optics, and holographic optical elements (HOEs) to steer the trap within the field of view of the microscope. Laser tweezers enable the trapping of a colloidal particle using radiation pressure by focusing a laser beam through a high-numerical aperture lens and manipulating the particle. Laser tweezers would be used to position particles and to measure the viscosity and viscoelasticity of the fluid. A particle can be trapped and oscillated at a fixed frequency. When this is done, the centroid of the trap and particle will not coincide; the difference in the two positions through the scan is a way to determine the driving force. Using this information, along with the motion, both linear and nonlinear viscoelastic properties can be computed.
PREMIER AUTOMATED ISS MICROSCOPE