The Sense in Earth Remote Sensing from the International Space Station

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In today’s A Lab Aloft blog entry International Space Station Chief Scientist Julie Robinson, Ph.D., shares the benefit to using the space station as a platform for Earth remote sensing instruments.

One of the amazing things that you’re going to see on the International Space Station in the coming years is its emergence as a serious remote sensing platform. Looking at the Earth from space gives researchers a powerful vantage point to study our planet’s water, air, vegetation, and more.

People in remote sensing are used to having their own satellites and putting those instruments at the perfect orbit so that they go over the ground at the perfect time. Fortunately, when the space station was designed, planners recognized that having a platform in low Earth orbit (LEO), which is about half the altitude of most Earth remote sensing satellites, provided researchers the opportunity to do something unique. Designers put locations on the station exterior that provide data, thermal and power support. Basically the space station is a giant, well-equipped satellite that can host a wide variety of remote sensing instruments—dozens of them.

A detailed view of the location for Stratospheric Aerosol and Gas Experiment III (SAGE-III) instrument, once it is externally mounted to the International Space Station. You can see the numerous other mounting locations available for other remote sensing investigations. (NASA)

A detailed view of the location for the Stratospheric Aerosol and Gas Experiment III (SAGE-III) instrument, once it is externally mounted to the International Space Station. You can see the numerous other mounting locations available for other remote sensing investigations. (NASA)

Now that the space station is complete, we are starting to see scientists take advantage of this platform as their sensors get launched and mounted. I want to talk a little bit about why these instruments are finding a valuable home on the space station. I also want to mention that there are openings through the Earth venture instrument opportunity and other calls via NASA’s Mission Directorate for both small, lower cost instruments and venture-class instruments. It’s wonderful to see the entire Earth science community looking at how the space station can help them achieve their research goals.

One huge advantage to using the space station is the frequent transportation to orbit. The abundant power and data capabilities are also tremendous benefits. Something else to consider is that station is a bit more jittery compared to other Earth remote sensing satellites, but engineers can adapt designs to work around this, as well as to manage contamination concerns for such a complex vehicle.

When I look at the instruments coming to the space station, one thing that is singular is the 51.6 degree inclination of our platform. That means that instead of passing over at the same time every day, which is typical of an Earth remote sensing satellite, the space station actually has a precessing orbit and does not go over the poles. In other words, the ground track moves westward along each of 16 daily tracks as it travels, with ground track repeats every three days, and a 63-daylight cycle. That gives you some unique opportunities. While at first it may not appear ideal for certain kinds of Earth remote sensing, researchers are working with that difference to turn it from a challenge into an asset.

The precessing orbit of the space station laid out over a map of the Earth. (NASA)

The precessing orbit of the space station laid out over a map of the Earth. (NASA)

What I’m seeing in the instruments coming forward are some trends in how they are using the space station to their advantage. One area is in the capability to fill data gaps using station-mounted sensors, specifically where other satellites have failed or not yet made it to orbit. Station provides a rapid turnaround opportunity to fill those data gaps, providing a fuller insight into each area of research.

A second trend I’ve noticed has to do with areas where there is a new airborne technology. People would like to have those get on global satellites, but first the instruments need to be tested and the technology refined. The space station is a great place to do that kind of advancement, so that in the future the more expensive satellite mission can be successful.

Another group of instruments are taking advantage of the diurnal—daytime and daily activity—variability of the station. For instance, if you have a sensor on a satellite in sun-synchronous orbit, it goes over the ground at the same time every day. When you add a second, parallel instrument you can take advantage of observing things at different times. Think of MODIS, which is going over the tropics daily at the same time. That area may be cloudy most of the time, because of the specific schedule. With the space station, however, you could now and then get that same data early in the morning before the clouds have built up.

The Earth's atmosphere seen in the thin blue line fading into the darkness of space, as photographed by a crew member aboard the International Space Station. (NASA)

The Earth’s atmosphere seen in the thin blue line fading into the darkness of space, as photographed by a crew member aboard the International Space Station. (NASA)

Another pattern we are seeing is the opportunity for cross-calibration, where researchers compare data sets from both the station- and satellite-related sensors. It can be really valuable to have a second instrument aboard station for this cross-validation of data. There are several instruments in orbit now, and the station will eventually pass under each of those sensors and simultaneously collect data. That allows for the cross-calibration of instruments that would otherwise be impossible.

With that as a background, here are a few highlights of instruments coming up for use aboard the space station for remote Earth sensing.

The Stratospheric Aerosol and Gas Experiment III (SAGE-III) is a spectrometer that uses occultation. This basically means that it looks at the light transmitted from the sun or the moon filtered through the atmosphere and measures the aerosols that are found there. SAGE-III is scheduled to launch to the space station in 2015. This latest spectrometer has a heritage of previous SAGE instruments that discovered the ozone hole, which we all know about now and that led to the 1987 Montreal Protocol.

The updated SAGE-III will help us understand atmospheric composition and long-term variability. The space station’s orbit is actually ideal for these types of occultation measurements. Having the opportunity to mount this major instrument to our platform is thrilling.

The Stratospheric Aerosol and Gas Experiment III (SAGE-III) instrument, seen in this artistic rendering, is scheduled to launch to the International Space Station in 2015. It will capture remote Earth sensing data of the aerosols in the atmosphere. (NASA)

The Stratospheric Aerosol and Gas Experiment III (SAGE-III) instrument, seen in this artistic rendering, is scheduled to launch to the International Space Station in 2015. It will capture remote Earth sensing data of the aerosols in the atmosphere. (NASA)

Another instrument that is going up to station very soon on SpaceX-5, scheduled for 2014, is a LIDAR instrument looking at clouds. Called the Cloud Aerosol Transport System (CATS), this sensor will mount to the JEM exposed facility. This is a case of testing an instrument that was developed for airborne use, but has not flown on a satellite yet.

What CATS does is it emits a laser light signal at three different wavelengths. It then looks at the signal that comes back to measure the layer height of the clouds, the layer thickness, the backscatter (the reflected light back), the optical depth and the depolarization. In so doing, CATS helps us understand the structure of those clouds. This is hugely important for global climate modeling, because clouds can function as insulators. They can prevent sun from getting to the ground, and they also can prevent heat from getting out of the Earth.

Sample LIDAR data from the airborne Cloud Physics LIDAR, predecessor to the Cloud Aerosol Transport System (CATS), showing cloud heights and aerosol layers. (NASA)

Sample LIDAR data from the airborne Cloud Physics LIDAR, predecessor to the Cloud Aerosol Transport System (CATS), showing cloud heights and aerosol layers. (NASA)

The ISS-RapidScat also is planned for launch to space station in the not too distant future. This is a radar scatterometer measuring ocean wind speeds. The instrument is a refurbished engineering model of the sea wind scatterometer that was on QuickScat, which had some failures. This updated version is a data gap filler and the information is used by the National Oceanic and Atmospheric Administration (NOAA) and other agencies in predicting hurricane intensification and understanding these major storms. The next satellite scatterometers that will go up are going to have intersections with ISS-RapidScat. It’s inspiring to see the cross-calibration capabilities that come with this series of instruments.

An artist rendering of the ISS-RapidScat aboard the International Space Station. This instrument will measure wind speeds to provide hurricane prediction data to researchers. (NASA)

An artist rendering of the ISS-RapidScat aboard the International Space Station. This instrument will measure wind speeds to provide hurricane prediction data to researchers. (NASA)

The space station provides this extraordinary emerging opportunity with rapid implementation of airborne and space-borne instruments to fill data gaps. This includes the ability to test an airborne technology globally before launching a premier satellite-based instrument, as well as the ability to take advantage of the somewhat unusual space station orbit tracks. We can capture diurnal opportunities that other instruments miss and even use the data to cross-calibrate across a constellation of sensors to really improve the quality of the overall global data sets.

We are going to have our first dedicated session for space station remote Earth sensing at this year’s American Geophysical Union meeting in San Francisco, from December 9-13, 2013. It is encouraging to have all of these newer science instruments coming to space station in the next year or two. I am thrilled to see the scientific community putting their creativity out there as they think about what instruments make sense for the space station and proposing those in solicitations.

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Julie A. Robinson, Ph.D.
International Space Station Chief Scientist

Julie A. Robinson, Ph.D., is NASA’s International Space Station Chief Scientist, representing all space station research and scientific disciplines. Robinson provides recommendations regarding research on the space station to NASA Headquarters. Her background is interdisciplinary in the physical and biological sciences. Robinson’s professional experience includes research activities in a variety of fields, such as virology, analytical chemistry, genetics, statistics, field biology, and remote sensing. She has authored more than 50 scientific publications and earned a Bachelor of Science in Chemistry and a Bachelor of Science in Biology from Utah State University, as well as a Doctor of Philosophy in Ecology, Evolution and Conservation Biology from the University of Nevada Reno.

 

Cool Flames on the International Space Station – An Anatomy of Discovery

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In today’s A Lab Aloft, Mike Hicks, project scientist at NASA’s Glenn Research Center in Cleveland, blogs about discovering the “cool” world of combustion aboard the International Space Station.

In a recent posting on this blog one of our International Space Station combustion researchers, Sandra Olson, noted that when it comes to combustion experiments in microgravity one should expect surprises. This has certainly proven to be true with one of our liquid fuel combustion investigations currently operating aboard the space station.

The Flammability and Extinction (FLEX) study burns liquid fuels dispensed in the form of small, single droplets. The goal is to answer two key questions: the first is how difficult it is to keep a flame burning in microgravity? We call this flammability mapping. The second is how effective is gaseous carbon dioxide (CO2) (or other diluents) in extinguishing spacecraft fires? Gaseous CO2 is particularly important because this is the current fire suppressant used in the U.S. module of the space station.

To answer these and other “burning questions” the FLEX team of scientists studies small droplets of fuel. This approach allows a large number of tests to take place under a wide range of conditions. The flame that results from igniting these fuel droplets (ranging in size from 1.0 mm to 6.0 mm in diameter) achieves a shape that can only happen in a reduced gravity environment—that is, they become little glowing balls of fire.

Image of a burning droplet in microgravity during a Flammability and Extinction (FLEX) test aboard the International Space Station. (NASA)

Image of a burning droplet in microgravity during a Flammability and Extinction (FLEX) test aboard the International Space Station. (NASA)

Within fractions of a second following ignition, the reaction front—visualized as a flame—quickly wraps around the fuel droplet and assumes a spherical shape. This remains mostly motionless until the droplet of fuel is consumed or until the conditions are such that the flame can no longer exist. You can watch the Strange Flames on the International Space Station video to see these microgravity flames in action.

The overarching goal of FLEX is to better understand the complicated physical processes behind determining whether or not a flame can exist in a given environment for a given fuel type. The environment varies based on the amount of oxygen in the combustion chamber along with other gases that balance out the test atmosphere.

Since combustion processes are rich in physics and chemistry, there are many parameters that play a role in flame survival. The FLEX experiments allow scientists a way to study these competing physical processes—such as the rate of fuel consumption, fuel characteristics, the controlling energy and mass transfer processes, and the physical properties of the gases that make up the test environment. By understanding and modeling these processes, we hope to better predict fire behavior in space. This also leads to Earth technology advances, such as more fuel efficient engine designs.

FLEX recently led us to a “cool” discovery, igniting the imaginations of many combustion researchers. During one of their many late night test sessions, the FLEX operations team noticed a very peculiar orange afterglow about 20 seconds after the flame had extinguished. It was so intense that the team first thought something else other than the fuel droplet was burning.

A cloud of condensed fuel, like a fog, forms around the heptane fuel droplet following its dual-stage extinguishment in the FLEX investigation. (NASA)

A cloud of condensed fuel, like a fog, forms around the heptane fuel droplet following its dual-stage extinguishment in the FLEX investigation. (NASA)

After a few repeated tests, the team concluded that this bright afterglow resulted from tiny droplets of re-condensed fuel vapor. The idea was that these tiny droplets formed a fog, scattering the yellow-orange backlight that is used to project the droplet’s shadow onto one of the diagnostic cameras. The afterglow was initially dismissed as an artifact of the test configuration—or so we thought.

A few days later we recovered the data from the space station and processed the images for accurate measurements. As we looked closely at the droplet shadow images we realized this glow was actually a clue to something new.

Typically when a flame extinguishes, the evaporation of the fuel droplet will nearly stop, and the droplet stops shrinking, which makes entirely good sense—no flame, well then, no fuel consumption. We discovered with FLEX that under certain conditions when the flame disappeared, the droplet of fuel continued to evaporate at almost the same rate as when the flame was visible. In many cases this “apparent” fuel consumption without a flame lasted longer than with the flame.

Video screen shot of a FLEX ignition test for a ~2.5 mm methanol fuel droplet formed on tip of needle. (NASA)

Video screen shot of a FLEX ignition test for a ~2.5 mm methanol fuel droplet formed on tip of needle. (NASA)

Even more startling, we saw that when the pressure of the chamber was slightly increased, the flame momentarily reappeared in a brief flash before quickly going out again. In some cases this phenomena repeated until the fuel was consumed. This finding has a number of interesting ramifications, both from a purely scientific perspective as well as from a fire safety perspective. It provides the first direct observation of a long held concern—the possibility that microgravity conditions were conducive to re-ignition of flammable mixtures.

Ignition of 4.5 mm droplet on tethering fibers (crossed fibers shown as glowing lines) developing into a large weak flame which quickly extinguishes (t = 10.8 seconds), followed by period of low-temperature burning (~ 2 seconds) with no visible flame, a brief return to high-temperature burning (for ~ 1.5 seconds at t = 12.9 seconds). This cycle repeated once, until the fuel droplet was completely consumed. (NASA)

Ignition of 4.5 mm droplet on tethering fibers (crossed fibers shown as glowing lines) developing into a large weak flame which quickly extinguishes (t = 10.8 seconds), followed by period of low-temperature burning (~ 2 seconds) with no visible flame, a brief return to high-temperature burning (for ~ 1.5 seconds at t = 12.9 seconds). This cycle repeated once, until the fuel droplet was completely consumed. (NASA)

At first glance, it seemed irrational that the fuel droplet continued to evaporate with no visible flame. Some of the science team argued, myself included, that this could be explained by characteristics of the test chamber environment. It was suggested that once the visible flame extinguished, that there was still a sufficient amount of energy remaining in the surrounding gases to continue the rate of the droplet’s evaporation.

Since buoyant forces are absent in microgravity flames, the hot gases simply remain stationary around the droplet—so we theorized that as these gases cooled, heat transferred back into the droplet. We quickly realized, however, that this would have resulted in a gradual slowing of the droplet’s evaporation rate, which was not the case. During the “dark burning periods” when no flame was visible, the evaporation rates were essentially constant, similar to what is seen with a visible flame. Interestingly, these evaporation rates suddenly stopped when the afterglow of the scattered light began to appear.

In 65 years of previous droplet experiments, and employing a staggering breadth of microgravity test configurations—from converted mine shafts in Japan to experiments performed on the recently retired space shuttles—this phenomena had never been observed. The prior universal observation was that when the flame went out, the rapid evaporation of the droplet stopped. However, with these tests we now had a fuel droplet that continued to be consumed at a rapid rate without an apparent flame.

NASA astronaut Karen Nyberg, Expedition 36 flight engineer, services the Combustion Integrated Rack (CIR) Multi-user Droplet Combustion Apparatus (MDCA) in the International Space Station's Destiny laboratory. This is the facility in which the FLEX investigation tests take place in orbit. (NASA)

NASA astronaut Karen Nyberg, Expedition 36 flight engineer, services the Combustion Integrated Rack (CIR) Multi-user Droplet Combustion Apparatus (MDCA) in the International Space Station’s Destiny laboratory. This is the facility in which the FLEX investigation tests take place in orbit. (NASA)

After a great deal of deliberation, the collective wisdom of the FLEX team came up with a theoretical explanation: “cool flames!” The technical explanation for this phenomena first appeared in Combustion and Flame in an article entitled “Can Cool Flames Support Quasi-Steady Alkane Droplet Burning?

So what exactly is a cool flame and why is it important? The discovery of cool flames is often attributed to Sir Humphry Davy in 1812. While investigating flames for the purpose of designing safety lamps for coal miners, Davy observed that he could generate flames in the lab that were so weak that they could would not even ignite a match. This finding was followed by W.H. Perkins, who published in 1882 the first investigation of cool flames. Perkins observed that vapors of organic fuels produced what he characterized as “blue lambent flames.” Generally speaking, cool flames are the visible light of oxidation reactions occurring at low temperatures, sometimes nearly 10 times less than normal flame temperatures.

This side-by-side image shows a comparison of a flame burning on Earth (left) and a flame in microgravity (right). (NASA)

This side-by-side image shows a comparison of a flame burning on Earth (left) and a flame in microgravity (right). (NASA)

Cool flame temperatures depend on fuel type and atmosphere. For n-heptane—the alkane fuel used in the FLEX experiments—cool flames appear at temperatures just above 600 degrees Fahrenheit. This is about 176 degrees Fahrenheit warmer than the temperature for baking bread and considerably less, by about 1,300 degrees Fahrenheit, than the flame one might roast a marshmallow over. Hence the name “cool flame.”

Despite the name, these flames’ temperatures are still sufficiently high to sustain chemical reactions. Understanding exactly what kind of chemical reactions are taking place, as well as the conditions necessary to propel the chemistry into the high temperature realm of hot flames, are key research areas in the study of cool flames.

Prior to the FLEX discovery, it was thought cool flames were primarily pre-ignition phenomena generally limited to pre-mixed gases. If you’ve ever taken your car in for engine knocking, you’ve experienced an example of this. Pockets of gas in the cylinder undergo low temperature reactions (i.e., cool flames) that result in poorly timed pressure peaks. These deviations from the optimal peak pressure timing that should occur shortly after spark ignition result in the noise often associated with engine knock.

The FLEX study, however, showed a post-ignition cool flame. This occurred in a controlled system where reactants are initially separated, requiring time to travel to the reaction zone, which we see as the flame. This appears as a relatively steady phenomenon, suggesting a delicate balance between heat generated by the reaction and heat losses to the surrounding—to date, only achievable in space.

The microgravity cool flame discovery is significant for a number of reasons. Low temperature combustion in internal combustion engines, for instance, offers a number of advantages: reduced emissions, less wear on engine parts and increased fuel efficiencies. A better understanding of these low temperature burning regimes may help address challenges facing new internal combustion technologies, such as the Homogenous Charge Compression Ignition (HCCI) and Reactivity Charge Compression Ignition (RCCI) engines. Since these technologies lack a spark for localized ignition, knowledge of cool flames may help with precise timing of the combustion event—based, in this case, on a reactant mixture that may only be partially pre-mixed.

Microgravity cool flames are exciting in their own right, because of the potential for refining our understanding of a very complicated combustion phenomena. This is true of all serendipitous discoveries, giving one more example of how the space station provides an opportunity for discoveries that would otherwise never get made.

Mike Hicks is pictured with his granddaughter, Emma, while roasting marshmallows over “cool” flames of another kind.

Mike Hicks is pictured with his granddaughter, Emma, while roasting marshmallows over “cool” flames of another kind. (Image Courtesy of Mike Hicks)

Mike Hicks, project scientist at NASA’s Glenn Research Center in Cleveland, has been with NASA for 22 years and is currently probing the mysteries of droplet combustion as a co-investigator on the Flammability and Extinction (FLEX) study. He is also the principal investigator on the Supercritical Water Mixture (SCWM) International Space Station flight investigation, which is designed to study precipitation phenomena in near-critical water. Hicks spends much of his free time as a doctoral candidate at Case Western Reserve University putting the finishing touches on a dissertation he plans to complete in the fall of 2013.

From Fluids to Flames: The Research Range of Space Station Physical Science

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In today’s A Lab Aloft, guest blogger Fred Kohl, Ph.D., International Space Station Physical Sciences Research project manager at NASA’s Glenn Research Center in Cleveland, talks about some of the physical science investigations that take place in microgravity aboard the space station.

Extremes are part of exploration, whether you’re talking about space travel or probing new areas of discovery to expand knowledge in a given science. So it is appropriate that the extreme environment of the International Space Station provides an ideal location to study physical sciences, from flames to fluids.

Removing gravity from the equation aboard this Earth-orbiting laboratory reveals the fundamental aspects of physics hidden by force-dependent phenomena where a fluid phase (i.e., a liquid or gas) is present. Such experiments, which investigate the disciplines of fluid physics, complex fluids, materials science, combustion science, biophysics and fundamental physics, use the station’s specialized experiment hardware to conduct studies that could not be performed on the ground.

The main feature differentiating the space station laboratory from those on Earth is the microgravity acceleration environment that is stable for long periods of time. Conducted in the nearly weightless environment, experiments in these disciplines reveal how physical systems respond to the near absence of buoyancy-driven convection, sedimentation, or sagging. They also reveal how other forces, which are small compared to gravity, can dominate the system behavior in space. For example, capillary forces can enable the flow of fluids in relatively wide channels without the use of a pump.

Other examples of observations in space include boiling in which bubbles do not rise, colloidal systems containing crystalline structures unlike any seen on Earth, and spherical flames burning around fuel droplets. Also observed was a uniform dispersion of tin particles in a liquid lead melt, instead of rising to the top as would happen in Earth’s gravity.

These findings may improve the understanding of material properties, potentially revolutionizing development of new and improved products for use in everything from automotives to airplanes to spacecraft. With so much to learn in the area of physical science and so many investigations, I would like to highlight several studies ongoing, upcoming or recently looked at aboard the space station.

Constrained Vapor Bubble-2 (CVB-2)

Studying mixed fluids in microgravity for CVB-2 provides data to further optimize the performance of wickless heat pipes. These pipes weigh less and have reduced complexity as compared to the more common construction with a wick. The CVB-2 study examines the overall stability, fluid flow characteristics, average heat transfer coefficient in the evaporator, and heat conductance of a constrained vapor bubble under microgravity conditions as a function of vapor volume and heat flow rate.

Findings from this research may lead to more efficient ways to cool electronics and equipment in space, while also applying to advances in Earth technologies such as air conditioning and refrigeration systems. Laptop computers also use this type of heat pipe technology to cool their electronics in order to prevent overheating.

Expedition 23 Flight Engineer T.J. Creamer works to setup Light Microscopy Module (LMM) and Constrained Vapor Bubble (CVB) hardware in the Fluids Integrated Rack (FIR) in the Destiny U.S. Laboratory. (NASA)

Expedition 23 Flight Engineer T.J. Creamer works to setup Light Microscopy Module (LMM) and Constrained Vapor Bubble (CVB) hardware in the Fluids Integrated Rack (FIR) in the Destiny U.S. Laboratory. (NASA)

Advanced Colloids Experiment (ACE)

ACE studies colloidal particles in space for use in modeling atomic systems and engineering new systems. These particles are big enough—in comparison to atoms—to be seen and recorded with a camera for evaluation. Conducting this study aboard the space station removes gravitational jamming and sedimentation so that it is possible to observe how order rises out of disorder, allowing researchers to learn to control this process. This could lead to greater stability and longer shelf life for products on Earth, such as paints, pharmaceuticals and other products based on colloids. Recently we launched additional hardware, consisting of a magnetic mixer and a drill kit, to use in mixing the samples for future ACE experiments.

The magnetic mixer and drill kit (pictured here before launch) will assist with mixing samples for Advanced Colloidal Experiments (ACE) aboard the International Space Station. (NASA)

The magnetic mixer and drill kit (pictured here before launch) will assist with mixing samples for Advanced Colloidal Experiments (ACE) aboard the International Space Station. (NASA)

Capillary Flow Experiment-2 (CFE-2)

The CFE investigation is a suite of fluid physics flight experiments designed to study large-length scale capillary flows and phenomena in low gravity. Testing will probe dynamic effects associated with a moving contact boundary condition, capillary-driven flows in interior corner networks, and critical wetting phenomena in complex geometries. The sample fluids flow in specific directions influenced by the shape of unique cylindrical containers called Interior Corner Flow (ICF) vessels.

For CFE-2 there are 11 units of fluids for astronauts to test. This research and the resulting math models based on the data findings helps with the design of more efficient fuel systems for spacecraft. This is because the engineers will be able to design the shape of the tank to take advantage of the way fluids move in microgravity. On Earth these findings may contribute to models to predict fluid flow for things like ground water transport, as well as the afore mentioned cooling technology advances for electronics.

Expedition 36 Flight Engineer Karen Nyberg conducts a session with a Capillary Flow Experiment (CFE) Interior Corner Flow vessel in the Harmony node of the International Space Station. CFE observes the flow of fluid, in particular capillary phenomena, in microgravity. (NASA)

Expedition 36 Flight Engineer Karen Nyberg conducts a session with a Capillary Flow Experiment (CFE) Interior Corner Flow vessel in the Harmony node of the International Space Station. CFE observes the flow of fluid, in particular capillary phenomena, in microgravity. (NASA)

Flame Extinguishment Experiment – Italian Combustion Experiment for Green Air (FLEX-ICE-GA)

The objective of this investigation is to observe and characterize evaporation and burning of renewable-type fuel droplets in high-pressure conditions. Test runs for this study recently took place in the Combustion Integrated Rack (CIR) aboard station. Research conducted in the CIR facility includes the study of combustion of liquid, gaseous and solid fuels. The CIR is made up of an optics bench, combustion chamber, fuel and oxidizer control, and five different cameras for performing combustion experiments in microgravity.

Researchers can use the results of these experiments to develop and validate thermo-chemical and chemical kinetics computer models of renewable liquid fuels for combustion simulation in engines. This helps with the design of the next generation of fuels and advanced engines. The computer models may reduce costs to industries and benefit the general public by accelerating the adoption of renewable fuels that are environmentally friendly.

NASA astronaut Tom Marshburn servicing the Combustion Integrated Rack (CIR) aboard the Destiny module of the International Space Station. (NASA)

NASA astronaut Tom Marshburn servicing the Combustion Integrated Rack (CIR) aboard the Destiny module of the International Space Station. (NASA)

Supercritical Water Mixture (SCWM)

The SCWM investigation will help researchers look at phase change, solute precipitation, and precipitate transport at near-critical and supercritical conditions of a dilute salt/water mixture. When water is taken into its supercritical phase—a temperature higher than 705 degrees Fahrenheit and a pressure higher than 3,200 psia—it becomes highly compressible and begins to behave much like a dense gas. In its supercritical phase water will experience some rather dramatic changes in its physical properties, such as the sudden precipitation of inorganic salts that are normally highly soluble in water at ambient conditions.

The primary science objectives of the SCWM investigation are to determine the shift in critical point of the liquid-gas phase transition in the presence of the salt, determine the onset and degree of salt precipitation in the supercritical phase as a function of temperature, and to identify the predominant transport processes of the precipitate in the presence of temperature and/or salinity gradients.

On Earth water reclamation from high-salinity aquifers, waste handling for cities and farms, power plants, and numerous commercial processes may benefit from the SCWM findings. A good understanding about the behavior of salt in near-critical and supercritical conditions also would assist designers of the next generation of reactors. With the knowledge gleaned from SCWM, they could possibly design systems that would operate without incurring large maintenance problems.

Sample cell filled with a dilute aqueous solution of sodium sulfate for the Supercritical Water Mixture (SCWM) investigation. (NASA)

Sample cell filled with a dilute aqueous solution of sodium sulfate for the Supercritical Water Mixture (SCWM) investigation. (NASA)

With the still relatively new frontier of microgravity research, there are many questions to pose and angles to consider. The scientists that pursue the answers using the laboratory we have available 200 miles above us are embarking on a journey of discovery that I dare say will yield some amazing findings. As Albert Einstein said, “To raise new questions, new possibilities, to regard old problems from a new angle, requires creative imagination and marks real advance in science.”

Fred Kohl is the International Space Station Physical Sciences Research project manager at Glenn. Since the mid-1980s, he’s been involved in the advocacy, definition, development and conduct of more than 250 experiments in ground-based facilities and aboard the space shuttles, Mir space station and the International Space Station in the disciplines of fluid physics, complex fluids, combustion science, fundamental physics, materials science and acceleration environment characterization. Before joining the microgravity program, he conducted research in high-temperature materials chemistry and high-temperature materials corrosion related to aircraft engine applications. He holds a B.S. in chemistry from Case Institute of Technology and a Ph.D. in chemistry from Case Western Reserve University.

Model Organisms: Shining Examples for Simple, Effective Biology Research

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In today’s A Lab Aloft blog entry Camille Alleyne, Ed.D., assistant program scientist for the International Space Station Program Science Office, shares with readers the role of model organisms in microgravity research.

Have you ever thought about why biologists use the term “model organism?” This does not imply that these particular species set an example for the others in their genus. Rather, they have characteristics that allow them easily to be maintained, reproduced and studied in a laboratory. Conducting basic research on model organisms also helps researchers better understand the cellular and molecular workings of the human body, in addition to how diseases propagate. This is because the origins of all living species evolved from the same life process that is shared by all living things.

Model organisms can be plants, microbes (e.g., yeast) or animals (e.g., flies, fish, worms and rodents), all of which are widely studied and have a genetic makeup that is relatively well-documented and well-understood by scientists. Researchers favor these organisms because they grow relatively quickly and have short generation times, meaning that they swiftly produce offspring. They also are usually inexpensive to work with and are quite accessible, making them ideal for experimentation.

Aboard the International Space Station, researchers conducting studies on animal and plant biology disciplines also prefer to use model organisms. In several investigations, scientists use these test subjects to advance their knowledge of the fundamental biological processes, as they are already well-known in the specific species based on ground experimentation. 

Researchers use model organisms to study how microgravity affects cells. Examining the impacts of the space environment on an organism’s development; growth; and physiological, psychological and aging processes can lead to a better understanding of certain diseases and issues associated with human health.

 

Space radiation hitting cell DNA.(NASA)

Space radiation hitting cell DNA.(NASA)

Cells behave differently in space than on Earth because the fluids in which the cells exist move differently in the microgravity environment. The fundamental nature of the cell changes, including its shape and structure, how signals pass back and forth between cells, how they differentiate or split, how they grow or metabolize and alterations to the tissue in which cells live. Developmental biologists can learn much from these adaptations.

The Biological Research in Canisters (BRIC) experiment series of space station investigations, for instance, focuses on the area of plant biology. The study uses the thale cress (Arabidopsis thaliana) as its model organism. Scientists look at the fundamental molecular biological responses and gene expression of these plants to the microgravity environment. This small, flowering plant already has a well-sequenced genome—meaning researchers already have a map for the heredity of organism’s genetic traits. These traits are what control the characteristics of an organism, such as how it looks, behaves and develops over time.

Thale cress (Arabidopsis thaliana) seedlings. (NASA)

Thale cress (Arabidopsis thaliana) seedlings. (NASA)

Thale cress is approximately three- to seven-tenths of an inch tall and can produce offspring in large quantities in about six weeks. It also has the advantage of a small genome size—so it’s not complicated to study—and an abundance of available genetic mutants—which allows for varied areas of research focus. Specifically in the BRIC-16 investigation, Anna-Lisa Paul, Ph.D., and Robert Ferl, Ph.D., at the University of Florida in Gainesville examined the changes in the genome sequencing and DNA of these plants. Results assisted space researchers in understanding how to maintain food quality and quantity for long-duration spaceflights, in addition to how to provide and maintain life-support systems. There also are Earth applications, including understanding basic plant processes that may increase our ability to control more effectively plants for agriculture purposes.

In the area of animal biology, there are numerous investigations that use a variety of model species as subjects. In the Micro-5 investigation, principal investigator Cheryl Nickerson, Ph.D., of Arizona State University—along with co-principal investigators Charlie Mark Ott, Ph.D., of NASA’s Johnson Space Center in Houston; Catherine Conley, Ph.D., at NASA’s Ames Research Center at Moffett Field, Calif.; and Dr. John Alverdy, University of Chicago—use an organism referred to as Caenorhabditis elegans. This human surrogate model helps us better understand the risks of flight inflections to astronauts during long-duration spaceflight.

C. elegans nemotodes, or round worms, undergo examination by project scientists. The worms are descendants of those that were part of an experiment that flew on space shuttle Columbia's final mission, STS-107. (NASA/Ames/Volker Kern)

C. elegans nemotodes, or round worms, undergo examination by project scientists. The worms are descendants of those that were part of an experiment that flew on space shuttle Columbia’s final mission, STS-107. (NASA/Ames/Volker Kern)

C. elegans are free-living, transparent nematodes, or roundworms, that live in temperate soil environments. They are inexpensive and easy to grow in large quantities—producing offspring with a generation time of about three days. Members of this species have the same organ systems as other animals, making it a great model organism choice. In this study, C. elegans will be infected with the salmonella (Salmonella typhimurium) microbe, which causes food poisoning in humans and is known to become more virulent in microgravity—meaning it increases its disease causing potential. Studying this host-pathogen combination provided researchers with insight into how this bacterium will respond in space explorers, if infected. The knowledge lays a solid foundation for the development of vaccines and other novel treatments for infectious diseases.

Another model is Candida albicans, which is an opportunistic fungus or yeast that exists in a dormant state in about three of every four people. It has greater potential to become active in individuals with compromised immune systems, hence the term “opportunistic.” When active, this pathogen causes thrush or yeast infections. Easily mutated, this organism’s genes are readily disrupted for study. Principal investigator Sheila Nielsen-Preiss, Ph.D., of the Montana State University in Bozeman, used this model for the Micro-6 investigation during Expedition 34/35. As in other model organisms, the well-understood genetic makeup of this fungus made it easier for scientists to identify changes that occurred in microgravity. This led to a better understanding or the fungus’ fundamental physiological responses and their ability to cause infectious diseases.

On a larger scale, one of the human body’s major adaptations to spaceflight is the loss of bone mineral density. Understanding the mechanisms by which bones break down and build back up in this extreme environment is critical to human space exploration. In order to understand these phenomena more fully, researchers study Medaka fish (Oryzias latipaes) in the Aquatic Habitat (AQH) aboard the space station.

The above image shows an Aquatic Habitat (AQH) specimen chamber housing Medaka fish for study. (JAXA)

The above image shows an Aquatic Habitat (AQH) specimen chamber housing Medaka fish for study. (JAXA)

These model animals found in Asia are used extensively in biological research. They are vertebrates—meaning they have backbones—making them a good choice for studying bone activity. Medaka also have a well-mapped genome, a short gestation period and reproduce extremely easily. They are resilient and can survive in water of various levels of salinity.

In the Medaka Osteoclast investigation, principal investigator Akira Kudo, Ph.D., of the Tokyo Institute of Technology, along with co-principal investigators Yoshiro Takano, DDS, Ph.D., of the Tokyo Medical and Dental University; Keiji Inohaya, Ph.D., of the Tokyo Institute of Technology; and Prof. Masahiro Chatani of the Tokyo Institute of Technology, studied the process by which bone breaks down via the activity of bone cells known as osteoclasts. The transparency of the fish gave researchers a view into the mechanism of this process that would not be possible with other fish species. The goal of this research is to advance our knowledge on human bone health, leading to development of treatments and countermeasures for both astronauts living in space and patients suffering from osteoporosis on Earth.

In the coming year, the space station will add two new facilities as research resources to house a couple of distinct model organisms. The first is a fruit fly (Drosophila melanogaster) habitat. This type of insect is one of the 1,200 species in the genus of flies that is particularly favorable in genetic research. You may be surprised to know that the genes of D melanogaster are very similar to those of humans. More than half of our genes that map to diseases have been found to match those of fruit flies.

Since fruit flies reproduce quickly and their genome is completely sequenced, they serve as good models to study diseases in a much shorter time than it would take via human research. In the context of human spaceflight, scientists will continue to use fruit flies as a model to test gene expression in the space environment, adding to work done on the space shuttle.

Sharmila Bhattacharya, Ph.D., is the principal investigator for the Fungal Pathogenesis, Tumorigenesis and Effects of Host Immunity in Space (FIT) fruit fly investigation. In this image, Bhattacharya is inspecting the fly experiment containers before flight. (NASA)

Sharmila Bhattacharya, Ph.D., is the principal investigator for the Fungal Pathogenesis, Tumorigenesis and Effects of Host Immunity in Space (FIT) fruit fly investigation. In this image, Bhattacharya is inspecting the fly experiment containers before flight. (NASA)

The second habitat coming to the space station will house rodents. Mice (Mus musculus) are the most widely known of the model species in scientific research, because their genetic code and physiological traits are very similar to humans. They are vertebrate mammals with a 10-week generation time. Their genome is very well-sequenced and understood, and they are easy to mutate and analyze. 

Mice, more than any of the other animal model organism mentioned here, allow researchers to study beyond just the cellular cycle. They have the opportunity to advance their fundamental understanding of other human systems such as the immune, cardiovascular and nervous systems, to name a few. Mice afflicted with various diseases, including osteoporosis, cancer, diabetes and glaucoma, can lead researchers to findings that advance treatment options.

These developments and findings from past, present and future investigations aboard the space station continue to enable biologists in their studies. As researchers better understand the adaptation of model organisms in a microgravity environment, they can facilitate future ways doctors will manage human health, both in space and on Earth.

Camille Alleyne, Ed.D., is an assistant program scientist for the International Space Station Program Science Office at NASA’s Johnson Space Center in Houston.

Camille Alleyne, Ed.D., is an assistant program scientist for the International Space Station Program Science Office at NASA’s Johnson Space Center in Houston. She is responsible for leading the areas of communications and education. Prior to this, she served as the deputy manager for the Orion Crew and Service Module Test and Verification program.  She holds a Bachelor of Science degree in Mechanical Engineering from Howard University, a Master of Science degree in Mechanical Engineering (Composite Materials) from Florida A&M University, a Master of Science degree in Aerospace Engineering (Hypersonics) from University of Maryland, and a doctorate in Educational Leadership from the University of Houston.

Could You Choose Just One? Looking Beyond the Top Ten Space Station Research Results Countdown

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In today’s A Lab Aloft entry International Space Station Program Scientist Julie Robinson, Ph.D., concludes her countdown of the top research results from the space station.

I’ve shared with you my top ten research results from the International Space Station in this blog series, and this is only the middle of the mission. With the space station scheduled to continue operating until at least 2020—and likely beyond—we continue with investigations that present us with more interesting facts and findings. Even as you read this entry, hundreds of investigations are active in orbit.

Whatever missions we look to tomorrow—including travel to an asteroid and Mars—they absolutely depend on the success of the space station. That is because the station was developed to return benefits and discoveries to us here on Earth. How we use the space station, both in our success as an industry and in returning benefits back to our nations and our economies, impacts everybody. If we don’t all take ownership to share this story, it makes our stakeholders look at our future ideas and say, “well yeah, that’s great for you, but what’s in it for the rest of the country.”

The International Space Station seen against the backdrop of the Earth, as photographed by the STS-130 crew aboard space shuttle Endeavour. (NASA)

The International Space Station seen against the backdrop of the Earth, as photographed by the STS-130 crew aboard space shuttle Endeavour. (NASA)

I was originally challenged to pick a set of top 10 research results by the organizers of an aerospace industry meeting, the International Astronautical Congress. Now I would like to challenge not only the members of the aerospace community, but all of those reading this blog who may one day benefit from this orbiting laboratory—that means you. Please take home one of these top ten research facts to share with your family, friends and colleagues. There are many more benefits and results than just those I highlighted, but it’s a good place to start.

Of the examples I gave you in this series, be ready to own the one that you choose. If you are talking with a government official, the press, your students, your family, that stranger sitting next you to on a plane, whomever you encounter, be prepared to share. The space station is our pinnacle of human spaceflight, it is our example of international cooperation and it is doing outstanding things in science yesterday, today and tomorrow. You don’t have to be a scientist to share the wonder and the value of the science we are doing there with others.

To make the difficult choice of a top 10 possible, there are a lot of things I didn’t include in the list. Sometimes, these were more technology spinoffs than research results. I also didn’t include the specific knowledge being gained for the purposes of future exploration—that could be another top 10 by itself. The use of space station ultrasound techniques in saving lives of women and their unborn children around the world, for instance. New remote ultrasound practices are being tested in developing nations, but this was a pure spinoff—no additional research needed—which is why it did not make my list. I also did not touch on the space station technology used today for air purification in daycares or the fresh water technology from station. Again, I did not select these primarily because they are pure spinoffs.

WINFOCUS and Henry Ford Innovation Institute members, Dr. Luca Neri and Alberta Spreafico work with Kathleen Garcia from Wyle Engineering to help train Dr. Chamorro from the rural community of Las Salinas, Nicaragua, using the ADUM and tele-ultrasound applications. (WINFOCUS/Missions of Grace)

WINFOCUS and Henry Ford Innovation Institute members, Dr. Luca Neri and Alberta Spreafico work with Kathleen Garcia from Wyle Engineering to help train Dr. Chamorro from the rural community of Las Salinas, Nicaragua, using the ADUM and tele-ultrasound applications. (WINFOCUS/Missions of Grace)

These examples are equally impactful and perhaps even more quickly connected to saving lives here on Earth. I encourage you to learn more by visiting our resources as we continue to share new developments, findings and benefits from space station research. Why limit this topic to so few as just ten; quite frankly, why limit the conversation to just the aerospace industry?

Amazingly enough, people you know have not heard about the space station, so we all need to take responsibility for sharing this message. There are some great resources we’ve put together as a partnership for you, so you won’t have to just remember the words you read here. You can look at the space station benefits for humanity website, which has been translated into multiple languages. You also can keep up on all the great things going on by following space station research on nasa.gov, revisiting this A Lab Aloft blog and by following our Twitter account: @ISS_Research.

I’d like to close by pointing out how sharing a view of the space station over your town can have a big impact on the people in your own orbit. My husband does not work in aerospace; he’s in the insurance industry. I remember one time there was going to be a great overpass of the space station in Houston, and I suggested to him that he go up on top of his building to see it. He sent an email around his office as an invitation and he ended up on the roof of the building with his colleagues and a senior executive. Together they watched this amazing space station pass. While looking up, the executive leaned over to my husband and said, “that was really neat! I had no idea we had people in space.”

One of our “people in space,” NASA astronaut Karen Nyberg works with the InSPACE-3 colloid investigation in the Microgravity Science Glovebox. (NASA)

One of our “people in space,” NASA astronaut Karen Nyberg works with the InSPACE-3 colloid investigation in the Microgravity Science Glovebox. (NASA)

The fact is that leaders in the world of business outside of aerospace are not paying attention to what we are doing. Science policy position and analysis can have scant information about what is really going on and what we are accomplishing. In the din of public policy debates, it is sometimes hard for us to get people hear about the good news. Two things that we really need to share with everyone are that the space station is up there with humans working on orbit, and that it is bringing back concrete benefits for use here on Earth. These returns make our economies stronger, make our individual lives better and save peoples’ lives. That really is the core of space exploration and why we do it.

Here, again, are my top ten space station research results in review.

10. Preventing the loss of bone mass in space through diet and exercise

9. Understanding mechanisms of osteoporosis and new ways to treat it

8. Hyperspectral imaging for water quality in coastal bays

7. Colloid self assembly using magnetic fields for development of nanomaterials

6. A new process of cool flame combustion

5. Pathway for bacterial pathogens to become virulent

4. Forty-three million students and counting

3. Dark matter is still out there

2. Robotic assist for brain surgery

1. New targeted method of chemotherapy drug delivery with breast cancer trials now in development

Thank you for sharing!

Julie A. Robinson, Ph.D.
International Space Station Program Scientist

Top Space Station Research Results Countdown: One, New Targeted Method of Chemotherapy Drug Delivery; Clinical Breast Cancer Trials Now in Development

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In today’s A Lab Aloft entry, International Space Station Program Scientist Julie Robinson, Ph.D., continues her countdown to the top ten research results from the space station, recently presented at the International Astronautical Conference in Beijing, China. Be sure to check back for daily postings of the entire listing.

Last, but not least in my International Space Station top ten countdown is a new targeted method of chemotherapy drug delivery, with breast cancer trials now in development. This treatment has the potential to change the landscape for how we address cancer—a devastating illness that has touched many of our lives—which is why the result ranks number one on my list.

This research goes clear back to Expedition 5 in 2002 when astronaut Peggy Whitson was aboard the space station for the first time. Scientists were interested in looking at whether or not microencapsulation—basically, building a microballoon that could contain a small amount of a chemotherapy drug—could do a better job of delivering that treatment to a tumor. There were some theoretical models that suggested that if you didn’t have gravity in the way, you could assemble these microballoons with better properties to streamline delivery right to the tumor site.

Single cell microencapsulation. (NASA)

Single cell microencapsulation. (NASA)

The Microencapsulation Electrostatic Processing System (MEPS) investigation proved that if you took gravity out of the equation, you could actually make these microencapsules with the right kind of properties. But of course you can’t make clinically useful quantities in space. So scientists spent the next five years perfecting a way to make these microballoons in clinically relevant quantities and clinical purity on the ground. Those technologies were licensed to a commercial company, which then began developing microencapsulation as a therapeutic measure. That process in itself can take decades.

If you asked me six months ago, I would not have even included this particular topic in the top ten. The reason it’s back on the list is because of the new work being done to adapt this technology for treating breast cancer. Clinical trials also appear to be getting closer, with MD Anderson Cancer Center in Houston. Researchers are finishing out the work that it takes to get FDA drug approval, so this is looking more promising for making it through to development, and finally to patient care.

Dr. Morrison with Microencapsulation Electrostatic Processing System (MEPS) flight hardware ready to pack for the International Space Station UF-2 mission. (NASA)

Dr. Morrison with Microencapsulation Electrostatic Processing System (MEPS) flight hardware ready to pack for the International Space Station UF-2 mission. (NASA)

As you can see from the span of the top ten, in research things go up and down and these developments can take decades. So the topic of targeted drug delivery for cancer treatment may fall off the list again, or it may successfully go all the way to the finish line. I think for sheer persistence in taking a great space station result and making it into something with lifesaving potential, the researchers and doctors working on this topic deserve credit for their endeavors. This is why they are number one on this year’s countdown.

Julie A. Robinson, Ph.D.
International Space Station Program Scientist

Top Space Station Research Results Countdown: Two, Robotic Assist for Brain Surgery

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In today’s A Lab Aloft entry, International Space Station Program Scientist Julie Robinson, Ph.D., continues her countdown to the top ten research results from the space station, recently presented at the International Astronautical Conference in Beijing, China. Be sure to check back for daily postings of the entire listing.

Number two on my countdown of International Space Station research results shows just how versatile the developments we’ve made for space can be when reexamined and repurposed for use on the ground. In this case, robotic assist for brain surgery is giving surgeons a helping hand to save the lives of patients with otherwise inoperable brain tumors and other diseases. I include this example not only as a technology spinoff, but to highlight the fact that it took a lot of research back on the ground to make this a reality.

The International Space Station Canadarm (pictured here) led to a technology spinoff to assist with brain surgery on Earth. (NASA)

The International Space Station Canadarm (pictured here) led to a technology spinoff to assist with brain surgery on Earth. (NASA)

The aptly named neuroArm technology came from the space station’s robotic arm. The Canadarm was developed by MDA for the Canadian Space Agency. For use in space, the arm needed to be resilient, perform well in doing critical space station assembly tasks without failing, and be able to continue operations while taking radiation hits. These specific traits made this technology ideal to translate for developing a robotic arm surgical assist. Doctors likewise needed equipment that they could trust to function consistently and that could go right inside an MRI and still operate effectively.

Paige Nickason, the first patient to have brain surgery performed by a robot, points to the area on her forehead where neuroArm performed surgery to remove a tumor from her brain. (Jason Stang)

Paige Nickason, the first patient to have brain surgery performed by a robot, points to the area on her forehead where neuroArm performed surgery to remove a tumor from her brain. (Jason Stang)

The neuroArm allows robotic guidance of brain surgery with keep out zones, such that physicians can remove tumors too close to sensitive areas of the brain for surgery by hand alone. The combination of having the MRI, the robotic guidance and the keep out zones allows the surgeon to do the procedure safely, without impacting the other areas of the brain. It is no wonder that Garnette Sutherland, M.D., University of Calgary, was recognized for outstanding results on advancing neurosurgery through space technology – named a top medical application from the space station for 2012.

The use of neuroArm has led to some extraordinary patient outcomes. The first set of research publications on the clinical trials published recently in the Journal of Neurosurgery for the initial 35 patients; many other patients have now had tumors successfully removed. This is a really exciting technology spinoff that also led to research results back here on Earth that are saving lives.

Julie A. Robinson, Ph.D.
International Space Station Program Scientist

Top Space Station Research Results Countdown: Three, Dark Matter is Still Out There

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In today’s A Lab Aloft entry, International Space Station Program Scientist Julie Robinson, Ph.D., continues her countdown to the top ten research results from the space station, recently presented at the International Astronautical Conference in Beijing, China. Be sure to check back for daily postings of the entire listing.

Number three on my countdown of the top ten International Space Station research results acknowledges that dark matter is still out there—and the space station is helping to find it. I want to start this entry out by apologizing to any astrophysicists reading this, as I am a biologist. But for all of those who are not astrophysicists, perhaps a biologist’s interpretation is a good one. Today I am focusing on the first results from the Alpha Magnetic Spectrometer (AMS) aboard the space station.

AMS is the most sophisticated magnet for making measurements of galactic cosmic rays that has ever existed. The state-of-the-art particle physics detector collects particles arriving from deep space, measures their energies, and most importantly the direction they are coming from. Particle physicists have dark matter as the best existing theory and keep trying to find evidence to either disprove it or get more information to validate it. Findings point to a new phenomenon that has researchers across the globe working to solve the cosmic puzzle of the origins of the universe through the pursuit of antimatter and dark matter.

Alphamagnetic Spectrometer (AMS) mounted externally to the International Space Station. (NASA)

Alphamagnetic Spectrometer (AMS) mounted externally to the International Space Station. (NASA)

One of the important sets of particles that the instrument is looking at are positrons. The first paper, published this year in Physical Review Letters, looked at positrons up to 300 giga electron volts (GeVs)—visible light has an energy of between 2 and 3 eV, by way of comparison. This is the same range studied with two other instruments, PAMELA and Fermi. But AMS has far greater accuracy than observations from these instruments. What the AMS results show is that there are far too many high energy positrons than can be explained from any established natural phenomenon. Those positrons appear to be coming not just from the center or the outside of the universe, but from every which direction.

The flux of high-energy particles near Earth (cosmic rays) can come from many sources. “Primary” particles (green) come from the original cosmic-ray source (typically, a supernova remnant). “Secondaries” (yellow) come from these particles colliding with interstellar gas and producing pions and muons, which decay into electrons and positrons. A third, interesting possibility is that electrons and positrons (purple) are created by the annihilation of dark matter particles, denoted by χ˜ in the figure, in the Milky Way and its halo. Note that for illustrative purposes the background image used here is of Andromeda, a typical spiral galaxy, roughly similar to ours. (GALEX, JPL-Caltech, NASA; Drawing: APS/Alan Stonebraker)

The flux of high-energy particles near Earth (cosmic rays) can come from many sources. “Primary” particles (green) come from the original cosmic-ray source (typically, a supernova remnant). “Secondaries” (yellow) come from these particles colliding with interstellar gas and producing pions and muons, which decay into electrons and positrons. A third, interesting possibility is that electrons and positrons (purple) are created by the annihilation of dark matter particles, denoted by χ˜ in the figure, in the Milky Way and its halo. Note that for illustrative purposes the background image used here is of Andromeda, a typical spiral galaxy, roughly similar to ours. (GALEX, JPL-Caltech, NASA; Drawing: APS/Alan Stonebraker)

The way Nobel Prize Laureate, Samuel Ting, Ph.D., summarized the findings in his paper was to say that these observations showed the existence of “new phenomena, whether from particle physics or from an astrophysical origin.” But of course what it really means is that the data is consistent with what you would see if dark matter were being annihilated and producing positrons.

Ting and his hundreds of colleagues have published additional papers on other particles at meetings during the summer. What’s really exciting, though, is the next set of data that Ting will publish. For example, the instrument is measuring positrons up to 1 Tera electron volt (TeV). The 300 GeV measurement matches all the other data, but as a good statistical sample builds and there is enough data on particle events to publish 300 GeV to the 1 TeV, all of that information will be completely new to science.

Big questions are out there. Even though we see events becoming rarer at high energies, will we continue to see an increased proportion of those? And at what energy levels and frequencies? All of that data becomes really important for answer the questions about the nature of dark matter and dark energy as we seek to unravel the mysteries of our universe.

Julie A. Robinson, Ph.D.
International Space Station Program Scientist

Top Space Station Research Results Countdown: Four, 43 Million Students and Counting

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In today’s A Lab Aloft entry, International Space Station Program Scientist Julie Robinson, Ph.D., continues her countdown to the top ten research results from the space station, recently presented at the International Astronautical Conference in Beijing, China. Be sure to check back for daily postings of the entire listing.

Research results can have exponential growth rates as scientists build on each other’s findings. That kind of inspiration carries with it innumerable possibilities that are in no way limited to the professional world. Number four on my list is 43 million students and counting—the number of students touched by the International Space Station’s educational endeavors. You can read more in the education publication: “Inspiring the Next Generation: International Space Station Education Opportunities and Accomplishments, 2000-2012.”

Cover of the education publication: “Inspiring the Next Generation: International Space Station Education Opportunities and Accomplishments, 2000-2012.” (NASA)

Cover of the education publication: “Inspiring the Next Generation: International Space Station Education Opportunities and Accomplishments, 2000-2012.” (NASA)

I included this educational topic in a list of investigation examples because it also links to key research on how you motivate students to take on careers in math and science. The statistical summary we put together during the last year across the space station partners included participation of 44 countries, 25 thousand schools, 2.8 million teachers, and 43.1 million students.

Of those students, 1.7 million participated in inquiring-based learning. This type of education is what research has shown us is really important and has set the recommendations of the National Science Teachers Association. When students test a hypothesis on their own or when they do work in their lab and compare it to what’s going on aboard the space station, they are most motivated towards math and science.

The YouTube Space Lab competition, Student Spaceflight Experiment Program (SSEP), and Zero Robotics are just a few examples of inquiry-based space station study done by students during the first 15 years of our mission. Google’s Zahaan Bharmal was recognized at this year’s International Space Station Research and Development Conference for the outstanding impacts from the YouTube Space Lab Project, a top education application. This is real research and contributes to education, while adding to the collective knowledge for various science disciplines.

Logo from the YouTube Space Lab competition that engaged students around the world to suggest and have the chance to launch their microgravity investigations to be conducted aboard the International Space Station. (YouTube Space Lab)

Logo from the YouTube Space Lab competition that engaged students around the world to suggest and have the chance to launch their microgravity investigations to be conducted aboard the International Space Station. (YouTube Space Lab)

The larger population of 43.1 million students learned about life in space from astronauts, gained encouragement through demonstrations, and built excitement by participating in educational programs. But those 1.7 million students that actually engaged in the scientific process themselves are the most likely to be the next explorers. They are the future employees of our agencies and companies currently working for aerospace and research today. This is an extraordinary impact from a spaceflight program and the inquiries of millions of students as they learn to become scientists is worth a place in the top 10 next to the research of today’s scientists.

Julie A. Robinson, Ph.D.
International Space Station Program Scientist

Top Space Station Research Results Countdown: Five, Pathway for Bacterial Pathogens to Become Virulent

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In today’s A Lab Aloft entry, International Space Station Program Scientist Julie Robinson, Ph.D., continues her countdown to the top ten research results from the space station, recently presented at the International Astronautical Conference in Beijing, China. Be sure to check back for daily postings of the entire listing.

We’re at the halfway point for my top ten research results for the International Space Station. As we kick off the second portion, I hope you have already learned something new to take home about our amazing orbiting laboratory.

Number five on our countdown is the pathway for bacterial pathogens to become virulent, in this case Salmonella. This is a topic that you may have heard about, because it was published in the Proceedings of the National Academy of Sciences. It has been heavily discussed by some of our stakeholders; the original discovery came from some human research focused investigations.

 

An example of Salmonella invading cultured human cells. (Rocky Mountain Laboratories, NIAID, NIH)

An example of Salmonella invading cultured human cells. (Rocky Mountain Laboratories, NIAID, NIH)

There was some indication from ground research that certain bacteria might become more pathogenic (more able to cause disease) when they went into space, in particular Salmonella bacteria. Salmonella infections results in 15,000 hospitalizations and 400 deaths annually in the United States. Cheryl Nickerson, Ph.D., from Arizona State University proposed to NASA that it may be good to look at this to find out if there was an increased risk for food borne illnesses in astronauts. NASA’s human research program funded the first study to fly these bacteria into space.

What researchers found was that the bacteria did become more able to cause this disease. More importantly, however, they identified the genetic pathway that was turning on in the bacteria, allowing the increased virulence in microgravity. This pathway had to do with the way that ions pass through the culture media. In a later study funded by NASA’s space life and physical sciences project, Nickerson was able to fly media that did not have those ions, and then control whether or not that bacteria became more or less virulent.

 

A photomicrograph of Salmonella bacteria. (Pacific Northwest National Laboratory)

A photomicrograph of Salmonella bacteria. (Pacific Northwest National Laboratory)

 

Astronaut Shane Kimbrough works with a Group Activation Pack (GAP) aboard the space shuttle Endeavour during an assembly mission to the International Space Station. (NASA)

Astronaut Shane Kimbrough works with a Group Activation Pack (GAP) aboard the space shuttle Endeavour during an assembly mission to the International Space Station. (NASA)

This is a great piece of scientific research showing the importance of doing biology experiments in this unique environment. There was a time when I would have had one of my top results be the possibility of developing vaccines on the ground—a private company did some additional studies in this area on the space station. Developing new medical treatments can take years, though, and have a lot of ups and downs. Right now that doesn’t appear to be developing as quickly as one might have hoped, so the jury is still out on the final benefit. Still, the core discovery here remains significant.

Scientists are working through other species of bacteria now, trying to understand if this is a common pathway. If so, how can we use it to increase or return benefits back to Earth, and can this new knowledge be used to help fight disease? Nickerson and colleagues continue to work on these questions, using the important discovery of this new pathway found through space station investigation.

Julie A. Robinson, Ph.D.
International Space Station Program Scientist

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