Feature

In microgravity, even seemingly indestructible materials degrade. Just look at the Hubble telescope, where its outer layer of insulation and thin layer of aluminum encasing have become so embrittled they are cracking and curling.

Without question, space is a harsh place where radiation, temperature extremes, orbital debris, and atomic oxygen (the presence of highly reactive single-oxygen atoms) flourish.

A new permanent test bed is now available on the exterior of the International Space Station (ISS) that allows investigators to analyze the durability of materials one sample or experiment at a time in the extreme space environment. The remotely controlled platform, the Materials ISS Experiment Flight Facility (MISSE-FF) from in-orbit commercial services provider Alpha Space Test & Research Alliance, LLC, aims to accelerate the testing of materials and components that have utility both in space and on Earth.

Building on NASA’s Legacy of Innovation

MISSE-FF, which launched on the 14^th SpaceX commercial resupply services mission in April 2018, builds on two decades of innovation by NASA. When the space shuttle was operating, NASA flew eight MISSE missions to the ISS, the last of which returned to Earth in 2014. The new MISSE design uses carriers to hold the experiments, which are launched and returned with each mission. Carriers from the current mission, MISSE-9, using the new MISSE-FF platform, are currently scheduled to return to Earth in December 2018 and April 2019.

In contrast to earlier MISSE missions, in which astronauts installed MISSE payloads on the outside of the ISS during a spacewalk and then later retrieved the experiments the same way for return to the ground, MISSE-FF is a permanent fixture on the space station. The platform’s individual experiment carriers are installed and removed using the robotic Canadarm2. Approximately 40 percent of the platform is reserved for NASA experiments, with the remaining 60 percent available for commercial use.

Research and development projects included in MISSE-9 will advance both space exploration and Earth-based innovations in solar technology, remote sensing, telecommunications, and other fields. MISSE-9 includes a suite of investigations, with samples including 3D-printed materials, sensors, sensor components, textiles, carbon-fiber laminates, paints, coatings, polymers, and composites. Within the first few weeks of MISSE-FF operation, Alpha Space had already received 1.2 million data packets (a unit of data made into a single package for transmission), including imagery of samples in various flight orientations.

“We built the MISSE-FF platform in less than three years, and now that it’s onboard the ISS, it’s running spectacularly,” said Alpha Space founder Stephanie Murphy, who brought together a team of engineers with prior MISSE experience to build the platform.

Murphy also leads MEI Technologies, a government contracting firm established in 1992 by Murphy’s father as Muñiz Engineering, Inc. MEI Technologies originally won the contract to privatize the MISSE platform, but it was Murphy’s idea to spin off Alpha Space into a standalone firm.

Driving New Understanding and Breakthroughs

Results from MISSE-9 investigations will not be fully realized until after the MISSE sample carriers housing the experiments return in winter 2018 and spring 2019 and samples or components are analyzed, but historical MISSE investigations have a legacy of advancing understanding and innovation in several industries on Earth.

For example, research on surface oxidation by atomic oxygen informs the design of fire-retardant and rust-resistant materials on Earth. Interactions between various materials and solar ultraviolet radiation could lead to better protective designs for communications and weather satellites and may help improve terrestrial structures, such as plastic siding for houses.

In addition, because true space environmental conditions are difficult to replicate on Earth, MISSE provides a valuable test platform that enables methods for correlating and extrapolating ground results. “That means that MISSE experiments can make ground testing more accurate and reliable,” said MISSE researcher Kim de Groh from NASA’s Glenn Research Center.

Most notably, of course, MISSE missions have provided space-environment durability data that enables the design of new, even more reliable spacecraft and innovative new structures for use in harsh environments both on and off Earth. Today’s satellites that are relied upon by hundreds of millions of people for Earth observation, weather, and communications were developed with materials tested in space on earlier NASA-led MISSE and related exposure missions.

These established benefits are appealing to a broad customer base. “We’ve attracted some really diverse initial clients,” said Murphy. “We’re in a lucky place where we can invite new users to the ISS National Lab, but our expenses are still being subsidized through the ISS National Lab and NASA. It’s a short-term incentive to bring entities and entrepreneurs into the fold that haven’t been there before.”

Besides traditional materials testing (e.g., paint, coatings, fabrics, and materials for 3D printing), Murphy noted that Alpha Space has had strong interest from customers studying “exobiology,” or the behavior of living things in the external space environment; for example, biological firms focused on medical applications.

An Unparalleled Platform for Tech Demo 

Firms wishing to demonstrate or test their space technology components and equipment in LEO are particularly drawn to the MISSE-FF platform. Two such technology demonstration experiments on MISSE-9 involve testing glass-free packaging for solar cells and assessing the robustness of optical receivers for communication in the harshness of space.

One experiment is from New Jersey-based Discovery Semiconductors, Inc., which makes fiber-optic modules and receivers for telecommunications, the military, and now LEO space applications.

“Demand for data bandwidth, which has been strong for terrestrial applications for many years, has started to migrate to space platforms,” said Abhay Joshi, owner of Discovery Semiconductors.

Joshi previously flew his fiber-optic components on MISSE-7 and has continued with the current MISSE-9 mission. He hopes the latest tech demo—involving two indium gallium arsenide high-end space receivers—will enhance the technology readiness level (TRL) of his company’s components.

The materials of the future and the component systems in which they are used are going to need to pass even more rigorous testing in extreme environments in order to operate and remain functional as they shrink in size and power consumption but increase in complexity and capability. The small satellite revolution is driven by advances in material performance and technologies proven in the harshness of space.

Like Joshi, Aarohi Vijh also sees value in the MISSE-FF platform for his technology components. Vijh heads new product definition and technical marketing for Alta Devices, a solar technology company in Sunnyvale, California. The company was founded 10 years ago by two researchers: Harry Atwater, of the California Institute of Technology, and Eli Yablonovitch, of the University of California, Berkeley.

Vijh and his team are studying a special kind of solar cell based on gallium arsenide (GaAs). GaAs solar cells were first developed in the early 1970s and have several unique advantages. GaAs is naturally robust to moisture and radiation, making it very durable. It has a wide and direct band gap allowing for more efficient photon absorption and high-output power density.

To create glass-free packaging for these solar cells so that they are lighter, less fragile, and better able to operate in space, Alta Devices tapped into years of NASA performance data on various plastics and polymers flown in space on MISSE missions. “In developing our own packaging solution, it made it a lot easier to look at what had already been done and proven,” Vijh said.

Vijh plans to continue to use the MISSE platform to evaluate his firm’s innovative solar arrays. “It’s a very powerful statement to make to our customers that our solar panels and packaging have actually been on a space flight with a credible provider,” he said.

Vijh sees applications on the ground as well. “The solar cells receive very high environmental exposure in space—ultraviolet rays and temperature cycling,” Vijh said. “The materials and our manufacturing techniques that we’re qualifying on MISSE will carry over to applications on the ground in the automotive industry and near-space applications such as high-altitude aircraft.”

Looking to the Future

On the NASA side, both de Groh and Sheila Thibeault, a member of the Advanced Materials and Processing Branch in the Research Directorate at NASA’s Langley Research Center, have experiments not only on MISSE-9 but also on MISSE-10, which recently launched to the ISS on Northrop Grumman CRS-10.

Thibeault served as an original founder of the MISSE project back in 1999, building the initial hardware used on MISSE-1 through MISSE-8. She also assisted with the redesign of MISSE to be remotely controlled, eliminating the need for spacewalks, and she and de Groh both advocated for a permanent MISSE platform on the space station.

“I’m really excited about MISSE missions continuing under Alpha Space leadership,” said Thibeault. She recalls how her team often had to take the machining of the carriers to NASA Langley’s machine shop, which was time consuming and involved some cost, and had to oversee quality control for incoming specimens from external partners, which also took time and resources.

“Alpha Space is making our life easier,” Thibeault said. “I can focus on my materials and the science and don’t have to worry about the platform or the specimen holders, which is all being taken care of for me.”

While it is still early in the platform’s performance history, Alpha Space executives believe the future is bright for MISSE-FF as a permanent test bed that will have a lasting impact on the quality of life at home and in space.

Optical fibers are the thread that connects our modern digital world. Smaller in diameter than a human hair, these fibers can transmit light pulses of information at billions of pulses per second and over distances of several thousand kilometers, eclipsing what is possible with electrical cables.

These optical fibers are most commonly made of silica (SiO₂) glass. While silica fibers are easily produced using well-established methods, optical losses in the fiber requires the use of expensive repeaters to boost the signal across long transmission distances.

The fluoride glass optical fiber, ZrF₄-BaF₂-LaF₃-AlF₃-NaF, commonly known as ZBLAN, at its theoretical best can have 10 to 100 times lower signal loss than silica fiber. However, when ZBLAN is produced on Earth, convection and other gravity-driven phenomena can cause imperfections because of the nonuniform distribution of the various chemical components within the fiber. These defects that occur during the process of solidification result in the formation of microcrystals that render the fibers unusable for many commercial applications.

To avoid the adverse effects of gravity, scientists have turned to the ISS National Lab to produce ZBLAN fiber in microgravity.

High-performance ZBLAN fibers would be extremely valuable back on Earth, and several commercial companies such as Fiber Optics Manufacturing in Space (FOMS), Made In Space (MIS), and Physical Optics Corporation (POC) are currently pursuing in-orbit production of ZBLAN fiber. Initial results have been promising, and successful ZBLAN fiber production on the ISS National Lab could pave the way for future large-scale commercial manufacturing of ZBLAN in low Earth orbit.

Why Microgravity?

To understand why microgravity is preferable over normal gravity for ZBLAN production, it is important to understand what about Earth’s gravity causes defects in the fibers. The production process on Earth involves draw towers that can be up to several stories tall. At the top of the tower is a preform, a large-diameter rod of the glass mixture, which is heated up so that a bead of glass falls, pulling a glass fiber behind it. Reaching the bottom of the tower, the fiber is wound on a spool to continue the draw from the preform. The whole process has been compared to that of pulling taffy.

When scientists talk about defects in ZBLAN optical fibers, they are mainly referring to crystallization and phase separation within the fibers. Due to convection-induced effects in molten ZBLAN glass, as well as other reasons researchers are still trying to determine, ZBLAN optical fibers made in Earth’s gravity are prone to having crystals form during the transition from a molten liquid state to a solid-like state.

“ZBLAN is desirable for many applications because it has a very large wavelength transmission window; even the current fibers with defects from ground production are used for transmission of infrared light,” said Michael Snyder, chief engineer and cofounder of MIS. “In theory, if you could suppress most or all of the crystallization in ZBLAN, the advantages of ZBLAN fiber, which include repeaterless transoceanic transmission of light, are huge compared to silica fiber.”

Using estimates for the theoretical loss limit of ZBLAN glass, a 2,000-km length of ZBLAN fiber could have the same optical loss as 10 km of silica fiber, which would be an extraordinary performance gain.

Because ZBLAN is made of five different elements (zirconium, barium, lanthanum, aluminum, and sodium) while silica fiber consists of only silicon dioxide, phase separation (boundary layers in the microstructure of a material) is more prevalent due to zirconium, barium, and lanthanum being denser than aluminum and sodium. Microgravity helps minimize this effect as well.

The Path to ZBLAN Production on the ISS

Before taking ZBLAN production to the ISS National Lab, POC used parabolic flight studies to test microgravity’s effects on ZBLAN production and optimize their hardware. “Results were encouraging,” said Ranjit Pradhan, vice president of applied technologies at POC. “The cross section of the glass pulled during parabolic flights was significantly more homogeneous than glass pulled on the ground.”

These promising results led to the development of POC’s Orbital Fiber Optic Production Module, which is scheduled for launch to the ISS on SpaceX’s Commercial Resupply Services (CRS)-17 mission in 2019. POC will first operate the system in microgravity to identify any unknown factors that could adversely affect the in-orbit production of high-quality ZBLAN fibers. Once optimization of the system is complete, the company plans commercial operations for in-orbit fiber manufacturing.

Similarly, FOMS leveraged its knowledge of past studies in the development of ruggedized hardware to develop the Space Facility for Orbital Remote Manufacturing (SpaceFORM), for which the company has an issued U.S. patent. SpaceFORM is intended to serve as not only a proof of concept but also a platform for volume production of optical fibers in microgravity.

SpaceFORM, which is capable of multi-kilometer fiber production, is scheduled to launch to the ISS on SpaceX CRS-17 in 2019, after which FOMS plans to conduct several in-orbit experiments aimed at testing and optimizing their hardware. FOMS hopes to gain insight into the fundamental physics of material processing in microgravity and the improvement pathways for the properties of the fiber produced in orbit. This knowledge will help in operationalizing a commercial in-orbit optical fiber manufacturing facility.

For MIS, successful parabolic flight testing led to the development of the company’s initial demonstration optical fiber puller, which launched to the ISS on SpaceX CRS-13 in December 2017. As part of their multi-flight Optical Fiber Production in Microgravity (OFPIM) experiment, this first investigation from MIS focused on evaluating the puller’s temperature settings.

The OFPIM hardware is entirely automated, which holds great promise for long-term commercial use due to the minimal crew time needed for unloading and plugging in samples—but perfecting the operation of the industrial process itself takes iteration. To this end, a second investigation from MIS that launched on SpaceX CRS-14 in April focused on testing several approaches for fiber-pulling techniques, and a third investigation on SpaceX CRS-15 in June further optimized the industrial process settings. A fourth investigation that launched on Northrop Grumman CRS-10 last month seeks to shift from pulling only test-length fibers to pulling fibers reaching up to 100 m in length for analysis.

This shift from validation to production of fibers for characterization and attenuation is an important step toward optimizing the OFPIM for commercial production of ZBLAN fibers in space for use back on Earth. The fibers pulled in testing so far have not been long enough for critical evaluation, but according to MIS, preliminary visual analysis of the fiber’s microstructure indicates an absence of the level of microcrystallization and flaws typically seen in terrestrially produced fiber.

Commercial Interest and the Future of Space Manufacturing

The core technology needed to produce commercial quantities of ZBLAN in microgravity is currently in development, and FOMS, MIS, and POC are each fine-tuning their methods of drawing optical fibers in space. For now, the ISS is the ideal platform to support the current level of space-based ZBLAN production. However, depending on the growth of the industry, the future could involve a new ISS module specifically dedicated to fiber pulling or even a new station or other platform for optical fiber manufacturing in low Earth orbit.

However, before large-scale commercial ZBLAN production in space can really take off, in-orbit manufacturing must become price competitive. “We are thankful to the ISS Commercial Space Utilization Program Office for funding this unique opportunity,” said Pradhan. The current round-trip costs of launching cargo to the ISS, performing experiments and procedures, and sending the cargo back down are prohibitive without NASA and the ISS National Lab subsidizing costs. According to Starodubov, though, this may not always be the case.

“The ongoing revolution of the space industry is making orbital processing amazingly affordable,” said Starodubov. “The costs will be dropping from the existing space trip cost, which is comparable to the price of platinum per kilogram, by roughly a factor of 10 in the near future.”

As costs start to come down, in-orbit manufacturing will become more accessible to smaller companies. And as more companies get involved, whether through the production of ZBLAN or other products, the cost of flying and returning cargo will continue to be driven further down, spurring an expansion of commercial manufacturing of products in space that have high value back on Earth.

In terms of the future Earth benefits of space-produced ZBLAN, Pradhan said that “given that ZBLAN performs closest to the theoretical best, space fibers could be used to wire up different continents.” Trans-oceanic telecommunication lines currently made of silica optical fibers could be replaced with high-performance microgravity-produced ZBLAN fibers.

“With such low optical loss,” said Pradhan, “the world could be connected like never before.”

In microgravity, even seemingly indestructible materials degrade. Just look at the Hubble telescope, where its outer layer of insulation and thin layer of aluminum encasing have become so embrittled they are cracking and curling.

Without question, space is a harsh place where radiation, temperature extremes, orbital debris, and atomic oxygen (the presence of highly reactive single-oxygen atoms) flourish.

A new permanent test bed is now available on the exterior of the International Space Station (ISS) that allows investigators to analyze the durability of materials one sample or experiment at a time in the extreme space environment. The remotely controlled platform, the Materials ISS Experiment Flight Facility (MISSE-FF) from in-orbit commercial services provider Alpha Space Test & Research Alliance, LLC, aims to accelerate the testing of materials and components that have utility both in space and on Earth.

Building on NASA’s Legacy of Innovation

MISSE-FF, which launched on the 14^th SpaceX commercial resupply services mission in April 2018, builds on two decades of innovation by NASA. When the space shuttle was operating, NASA flew eight MISSE missions to the ISS, the last of which returned to Earth in 2014. The new MISSE design uses carriers to hold the experiments, which are launched and returned with each mission. Carriers from the current mission, MISSE-9, using the new MISSE-FF platform, are currently scheduled to return to Earth in December 2018 and April 2019.

In contrast to earlier MISSE missions, in which astronauts installed MISSE payloads on the outside of the ISS during a spacewalk and then later retrieved the experiments the same way for return to the ground, MISSE-FF is a permanent fixture on the space station. The platform’s individual experiment carriers are installed and removed using the robotic Canadarm2. Approximately 40 percent of the platform is reserved for NASA experiments, with the remaining 60 percent available for commercial use.

Research and development projects included in MISSE-9 will advance both space exploration and Earth-based innovations in solar technology, remote sensing, telecommunications, and other fields. MISSE-9 includes a suite of investigations, with samples including 3D-printed materials, sensors, sensor components, textiles, carbon-fiber laminates, paints, coatings, polymers, and composites. Within the first few weeks of MISSE-FF operation, Alpha Space had already received 1.2 million data packets (a unit of data made into a single package for transmission), including imagery of samples in various flight orientations.

“We built the MISSE-FF platform in less than three years, and now that it’s onboard the ISS, it’s running spectacularly,” said Alpha Space founder Stephanie Murphy, who brought together a team of engineers with prior MISSE experience to build the platform.

Murphy also leads MEI Technologies, a government contracting firm established in 1992 by Murphy’s father as Muñiz Engineering, Inc. MEI Technologies originally won the contract to privatize the MISSE platform, but it was Murphy’s idea to spin off Alpha Space into a standalone firm.

Driving New Understanding and Breakthroughs

Results from MISSE-9 investigations will not be fully realized until after the MISSE sample carriers housing the experiments return in winter 2018 and spring 2019 and samples or components are analyzed, but historical MISSE investigations have a legacy of advancing understanding and innovation in several industries on Earth.

For example, research on surface oxidation by atomic oxygen informs the design of fire-retardant and rust-resistant materials on Earth. Interactions between various materials and solar ultraviolet radiation could lead to better protective designs for communications and weather satellites and may help improve terrestrial structures, such as plastic siding for houses.

In addition, because true space environmental conditions are difficult to replicate on Earth, MISSE provides a valuable test platform that enables methods for correlating and extrapolating ground results. “That means that MISSE experiments can make ground testing more accurate and reliable,” said MISSE researcher Kim de Groh from NASA’s Glenn Research Center.

Most notably, of course, MISSE missions have provided space-environment durability data that enables the design of new, even more reliable spacecraft and innovative new structures for use in harsh environments both on and off Earth. Today’s satellites that are relied upon by hundreds of millions of people for Earth observation, weather, and communications were developed with materials tested in space on earlier NASA-led MISSE and related exposure missions.

These established benefits are appealing to a broad customer base. “We’ve attracted some really diverse initial clients,” said Murphy. “We’re in a lucky place where we can invite new users to the ISS National Lab, but our expenses are still being subsidized through the ISS National Lab and NASA. It’s a short-term incentive to bring entities and entrepreneurs into the fold that haven’t been there before.”

Besides traditional materials testing (e.g., paint, coatings, fabrics, and materials for 3D printing), Murphy noted that Alpha Space has had strong interest from customers studying “exobiology,” or the behavior of living things in the external space environment; for example, biological firms focused on medical applications.

An Unparalleled Platform for Tech Demo 

Firms wishing to demonstrate or test their space technology components and equipment in LEO are particularly drawn to the MISSE-FF platform. Two such technology demonstration experiments on MISSE-9 involve testing glass-free packaging for solar cells and assessing the robustness of optical receivers for communication in the harshness of space.

One experiment is from New Jersey-based Discovery Semiconductors, Inc., which makes fiber-optic modules and receivers for telecommunications, the military, and now LEO space applications.

“Demand for data bandwidth, which has been strong for terrestrial applications for many years, has started to migrate to space platforms,” said Abhay Joshi, owner of Discovery Semiconductors.

Joshi previously flew his fiber-optic components on MISSE-7 and has continued with the current MISSE-9 mission. He hopes the latest tech demo—involving two indium gallium arsenide high-end space receivers—will enhance the technology readiness level (TRL) of his company’s components.

The materials of the future and the component systems in which they are used are going to need to pass even more rigorous testing in extreme environments in order to operate and remain functional as they shrink in size and power consumption but increase in complexity and capability. The small satellite revolution is driven by advances in material performance and technologies proven in the harshness of space.

Like Joshi, Aarohi Vijh also sees value in the MISSE-FF platform for his technology components. Vijh heads new product definition and technical marketing for Alta Devices, a solar technology company in Sunnyvale, California. The company was founded 10 years ago by two researchers: Harry Atwater, of the California Institute of Technology, and Eli Yablonovitch, of the University of California, Berkeley.

Vijh and his team are studying a special kind of solar cell based on gallium arsenide (GaAs). GaAs solar cells were first developed in the early 1970s and have several unique advantages. GaAs is naturally robust to moisture and radiation, making it very durable. It has a wide and direct band gap allowing for more efficient photon absorption and high-output power density.

To create glass-free packaging for these solar cells so that they are lighter, less fragile, and better able to operate in space, Alta Devices tapped into years of NASA performance data on various plastics and polymers flown in space on MISSE missions. “In developing our own packaging solution, it made it a lot easier to look at what had already been done and proven,” Vijh said.

Vijh plans to continue to use the MISSE platform to evaluate his firm’s innovative solar arrays. “It’s a very powerful statement to make to our customers that our solar panels and packaging have actually been on a space flight with a credible provider,” he said.

Vijh sees applications on the ground as well. “The solar cells receive very high environmental exposure in space—ultraviolet rays and temperature cycling,” Vijh said. “The materials and our manufacturing techniques that we’re qualifying on MISSE will carry over to applications on the ground in the automotive industry and near-space applications such as high-altitude aircraft.”

Looking to the Future

On the NASA side, both de Groh and Sheila Thibeault, a member of the Advanced Materials and Processing Branch in the Research Directorate at NASA’s Langley Research Center, have experiments not only on MISSE-9 but also on MISSE-10, which recently launched to the ISS on Northrop Grumman CRS-10.

Thibeault served as an original founder of the MISSE project back in 1999, building the initial hardware used on MISSE-1 through MISSE-8. She also assisted with the redesign of MISSE to be remotely controlled, eliminating the need for spacewalks, and she and de Groh both advocated for a permanent MISSE platform on the space station.

“I’m really excited about MISSE missions continuing under Alpha Space leadership,” said Thibeault. She recalls how her team often had to take the machining of the carriers to NASA Langley’s machine shop, which was time consuming and involved some cost, and had to oversee quality control for incoming specimens from external partners, which also took time and resources.

“Alpha Space is making our life easier,” Thibeault said. “I can focus on my materials and the science and don’t have to worry about the platform or the specimen holders, which is all being taken care of for me.”

While it is still early in the platform’s performance history, Alpha Space executives believe the future is bright for MISSE-FF as a permanent test bed that will have a lasting impact on the quality of life at home and in space.

Rocket scientists, real meteorite pieces, big telescopes on loan from astronomical societies—and mixed in with it all, students in grades 5 through 12 presenting their own experiments, each hoping to be selected as a finalist to possibly have their experiment fly to the International Space Station (ISS).

This is the scene at Space Night in Burleson, Texas, a community event put on by the Burleson Independent School District (ISD) designed to get families, students, and community members excited about science and spaceflight research and to allow students an opportunity to present the experiments they are submitting for Step 1 Review as part of the National Center for Earth and Space Science Education’s (NCESSE) Student Spaceflight Experiments Program (SSEP).

Burleson ISD began participating in SSEP during the 2014–2015 school year, a year after the new superintendent Bret Jimerson came onboard with the mission of getting more students engaged in science, technology, math, and engineering (STEM). “He wanted to unify everyone around an idea of STEM and progress and innovation. That’s where SSEP comes in,” said Leslie Bender Jutzi, Burleson’s chief academic innovation officer.

Recognizing the power of space to inspire and engage students, Jimerson’s first project for the district was SSEP, a program in which they have participated and excelled every year since. With the success of SSEP within their community, the Burleson ISD Academic Innovation Department has expanded their program offerings to include options in robotics, drones, xeriscaping (a landscaping method that reduces the need for irrigation), and additional space topics and research opportunities, covering a wide range of age groups.

Engaging Students in Real Science

The primary mission of the ISS National Lab is to benefit life on Earth, something that SSEP tackles through inspiring young scientists. SSEP is unique because it engages students in every aspect of STEM through a research competition in which the winners get to imagine, design, and send an experiment to space—an immersive learning experience that aligns well with Next Generation Science Standards.

The thought of designing a spaceflight experiment is an irresistible lure for students in grades 5 through 12, who are the primary focus of the program. Instead of the traditional model of doing well-established experiments in science class, students are challenged to research a topic and come up with an experiment worthy of microgravity study.

“I think the idea of flying an experiment to the International Space Station is what draws them in initially, but what we found from most of our students is that being treated as professional scientists was a better experience for them than anything in terms of actually flying the experiment,” said Stacy Hamel, SSEP Senior Flight Operations Manager for the NCESSE.

For each SSEP mission, a call is put out for interested communities to submit an implementation plan detailing how SSEP will be used to meet strategic needs in STEM education for their community. Once communities join the program, students are required to submit proposals just like those written by practicing scientists. With the help of their teachers, students split into small teams of typically three to five students and learn how to do the most basic and often overlooked part of science: experimental design and proposal writing.

Over a nine-week period, students come up with research questions and think of ways to answer the questions within certain parameters set as part of the competition. Students must also plan a ground control experiment that is conducted simultaneously on Earth to understand how spaceflight affects experimental outcomes. This allows students to compare experimental results in microgravity with results from Earth-based controls.

Typically, only one experiment flies from each participating community, so the competition is tough. Once students craft proposals, a local review board comprised of experts within the community selects three finalists to be moved on to national review, where a committee of experts assembled by the NCESSE selects the winning experiment for flight.

Fitting into Tight Spaces

Perhaps the most challenging part of the competition is that students must come up with an experiment that can fit within the parameters of the lab space available on the ISS. The NanoRacks Fluid Mixing Enclosure (called “MixStix”), the mini-laboratory utilized by SSEP, is essentially a silicone tube that can hold small amounts of fluids or solids in up to three separate compartments.

Students may use either one or two clamps to separate samples. Once in space, ISS crew members can open the clamps at different time intervals to start and stop the experiment. The MixStix can hold up to 10 mL of samples or up to 8.2 mL total with the use of two clamps.

“So, for example, students can load a seed and a substrate in volume 1, water and a liquid fertilizer in volume 2, and a fixative in volume 3,” said Hamel. Students then write a protocol for ISS crew members with instructions on when to open the clamps and any other simple tasks that may be needed, such as shaking the sample on a certain day.

For tenth grader Deidre Morales from Ector County, Texas, designing her experiment to fit within the confines of the MixStix meant rethinking the entire experiment in a more creative way. Morales wanted to study ways to get rid of space trash, and while doing her preliminary research, she found a worm that degrades polyethylene (the most common plastic). However, the worm did not fit in the MixStix, so Morales had to go back to the drawing board.

The bacterium would fit in the MixStix, but first Gray and her students needed to figure out how to get it to the United States. By reading through the scientific literature, they were able to track down the lab in Japan, and with the help of the Ector County ISD Innovation Department, they were able to collaborate internationally to get the bacterium from Japan to Texas.

“It took us five weeks to get it because we had to order it online and get approval from the United States Department of Agriculture to make sure it would not be harmful to anyone,” said Gray. It was a unique opportunity that allowed the students to not only learn about a new bacterium but also learn about government policies and international collaboration in the sciences.

A New Approach to Science Education

Perhaps the most important goal of SSEP is that for many students, the program fosters true engagement in STEM subjects that goes beyond merely achieving high test scores. Getting good grades, while important to many students, does not necessarily lead to an increased interest in a subject.

As an authentic learning competition, SSEP does just that. Through the hook of helping astronauts onboard the ISS, or someday on Mars, students learn how to design an experiment, write a proposal, present their idea to local review boards, and, if selected to fly their experiment to the ISS, present the outcomes of their research at a national conference, typically held at the Smithsonian National Air and Space Museum.

These are skills that many scientists do not learn until college or even graduate school. “It’s definitely a novel approach to science education, and it takes students from learners to actual practicing scientists,” said SSEP’s Hamel.

For the students, it is exciting to be treated like a scientist, even though it is hard work. For sixth-grade student researcher and SSEP principal investigator Gabriel McCarthy from Burleson ISD, participating in SSEP had been a dream since he was in third grade. McCarthy’s career goal is to become an astrophysicist, and he had been looking forward to competing in SSEP since he first heard about the competition.

In participating in SSEP and having his experiment “The Effects of Microgravity on Penicillum Mold Growth” selected for flight, McCarthy not only grew to understand just how much work goes into science, but he also got to experience new opportunities that were never available to him before.

Working with local universities is a unique opportunity and often one of the most valued experiences for students. McCarthy and his team worked with Clark Jones, a biology instructor at TCU, in his microbiology lab while preparing their sample for launch to the ISS. McCarthy also had the opportunity to work with Hana Dobrovolny, an assistant professor of biophysics at TCU, and to participate in TCU’s Student Research Symposium.

“Dr. Dobrovolny taught me more about cell growth, and it has been a unique experience,” McCarthy said. “She’s challenged me in math and coding in order to make graphs and taught me how to model cell growth within equations.”

McCarthy also learned how different concentrations of chemicals, like medications or nutrients, can affect tumor cell growth and has been invited to participate in TCU’s Student Research Symposium this year for the second time. For a sixth-grade student, this is typically an unheard-of opportunity.

Inspiring Young Scientists

Although the draw of flying an experiment to space is powerful, the benefits of SSEP extend beyond any single student or any one winning team. “SSEP touches every single aspect of STEM literacy,” said Gray, who reported higher interest in STEM subjects among her students after participation in SSEP.

For many other communities, the results were similar. More than 12,000 students participated in microgravity experimental design and proposal writing for SSEP’s Mission 12. In the end, even though only some students had their experiment chosen to fly to the space station, the impact on all participating students was significant. Through the process of being treated like actual scientists and conducting real science, SSEP instills in students the idea that anyone can be a scientist.

Every three seconds, a person somewhere in the world breaks a bone due to osteoporosis—a progressive disease that decreases bone density, making bones weak and fragile. Osteoporotic fractures greatly reduce quality of life, and immobilization following a fracture can lead to further bone loss which puts these patients at risk for breaking another bone.

When SpaceX CRS-11 launched to the space station last June, it carried 40 mice to the ISS National Lab for a mission aimed at improving treatment for the millions of people with osteoporosis back on Earth. The Rodent Research (RR)-5 mission successfully proved the robustness of a  new potential osteoporosis therapy based on a naturally produced protein, NELL-1, and also led to significant improvements in the delivery of the therapy.

Most current osteoporosis drugs only work to slow bone breakdown, not form new bone. A therapeutic approach using NELL-1 being developed by a group of researchers at the University of California, Los Angeles (UCLA) works both ways. NELL-1 has been shown to not only help prevent further bone loss but also build new bone to replace what was lost. Such a therapy would be of tremendous benefit to patients with severe osteoporosis.

To further evaluate the effectiveness of NELL-1, the UCLA team, led by principal investigator Chia Soo, tested its therapeutic use in mice onboard the ISS National Lab. Microgravity has been shown to induce accelerated bone loss in mice at rates that exceed those caused by either post-menopausal or disuse osteoporosis on Earth, making space an ideal environment to study osteoporosis therapies.

LINKING NELL-1 AND BONE FORMATION

NELL-1 is a protein made by the body, and its bone-forming effects were originally discovered more than 20 years ago by craniofacial orthodontist and RR-5 co-investigator Kang Ting. He had been examining children with a condition that causes an overgrowth of bone in the skull and wondered whether looking at gene expression in these patients could reveal a protein involved in bone growth.

Ting said, “The question was, can we find a way to see what induces bone formation in patients with too much bone? Can we find the protein and use it to help people who need bone?”

After screening millions of genes, Ting found one protein—NELL-1—that was overexpressed in children with skull bone overgrowth, leading him to begin investigating NELL-1 as a bone-forming agent. Following results from an independent research group that linked the underexpression of NELL-1 in patients to low bone density, Ting and his UCLA colleagues found that mice lacking NELL-1 exhibit symptoms of osteoporosis as they age.

In several animal models, the UCLA team was able to demonstrate the use of NELL-1 as a successful osteoporosis treatment; however, use of the protein as a therapy was possible only via local administration. In other words, the NELL-1 protein would have to be injected directly into a patient’s affected bone during surgery.

To make NELL-1 more useful for patients with osteoporosis, the team needed to modify NELL-1 to administer it systemically. This type of therapy could be given as a quick injection under the skin to build bone throughout the body.

As the UCLA researchers began working to modify NELL-1 for systemic use, they submitted a proposal to test the therapy in the microgravity environment on the ISS National Lab and were awarded a CASIS grant, which supported the RR-5 mission. Once modification of the molecule was complete, the team could launch their investigation to the space station.

MODIFYING THE MOLECULE

Developing NELL-1 into a systemic therapy that could be given as an injection every couple of weeks to build bone would greatly benefit patients; however, modifying the molecule to achieve this was no easy task. The team needed to find a way to keep the therapeutic protein molecules circulating in the blood long enough for NELL-1 to induce bone formation. The molecules also needed to be able to successfully and exclusively attach to bone tissue to be effective and safe.

Additionally, ISS crew members have typically accessed mice on the space station once every 14 days, so the interval between injections had to be at least that long. Keeping NELL-1 in the bloodstream for such a long period was a tremendous challenge. Moreover, with such a long circulation time, the team needed to reduce any toxicity so that the therapy would be safe.

With the help of Benjamin Wu, RR-5 co-investigator and former chairman of the UCLA Department of Bioengineering, the team modified NELL-1 using a method called PEGylation, which slows the rate at which molecules are degraded by the liver. This would keep NELL-1 circulating in the bloodstream longer. Then, to help NELL-1 find bone tissue, the team attached the protein to an inactive form of a bone-seeking molecule called bisphosphonate.

The team tested the modified molecule, called BP-NELL-PEG, in a ground-based experiment using female mice whose ovaries had been surgically removed to induce osteoporosis. The team found that injection of the therapy into the abdomen of the mice once every 14 days was successful.

Developing the therapy with a 14-day injection interval was one of the greatest technical challenges the team faced, but successfully extending the dosing interval will also be a substantial benefit to patients, Kwak said. Patients would need fewer injections of BP-NELL-PEG compared with most current osteoporosis drugs. This would not only save extra trips to the doctor’s office, but also make the therapy more affordable.

“Our work on the RR-5 mission really helped us make the delivery more effective and targeted, and it significantly increased the eventual clinical feasibility of the therapy,” said RR-5 principal investigator Chia Soo. “If you have an easier way to deliver the therapy and if you don’t have to deliver it as frequently, it has a much greater human application.”

Having successfully optimized the molecule and achieved the 14-day injection interval necessary for rodent research on the space station, the team was now ready to test the systemic therapy in the extreme case of microgravity-induced bone loss.

SENDING MICE TO THE SPACE STATION

SpaceX CRS-11 launched to the space station last June with the RR-5 mission, carrying 40 female mice aged to 8 months, which is when they reach skeletal maturity. An additional 40 mice remained on the ground at NASA’s Kennedy Space Center as a control group. In both the flight and ground groups, half the mice received BP-NELL-PEG treatment and the other half did not.

The RR-5 mission was unique in that halfway through the nine-week investigation, 20 mice in the flight group (10 receiving treatment and 10 not) were returned to Earth alive to complete the rest of the experiment on the ground at UCLA. The other 10 mice remained on the space station until the end of the investigation when they were sacrificed, and the frozen specimens were returned on SpaceX CRS-12.

Many analyses can only be performed on live tissues and cells, so live return was important to the RR-5 team. When the SpaceX Dragon capsule splashed into the Pacific Ocean last July with the RR-5 live-return mice, the team was elated to find that all 20 mice were alive and healthy. The team also noticed that the fur of the mice was shiny within a day of live return to UCLA, meaning they had been grooming—an indication of contentment.

“Our live return involved full survival of the animals, and they were safe, healthy, and happy,” Kwak said. “This is a huge milestone, and the exciting part for our science team is that all of our data will be very reliable.”

ANALYZING DATA AND LOOKING TO THE FUTURE

The RR-5 team is still in the process of analyzing all the data, but preliminary results indicate the investigation was a success. Data from the hind limbs and vertebrae of the spaceflight mice showed significant bone loss from microgravity and a remarkable recovery by BP-NELL-PEG treatment.

From here, the team plans to probe deeper into the molecular biology of the NELL-1 protein to gain a more detailed understanding of how the molecule works, while continuing to focus on the practical translational aspects of the therapy.

“We want to look at how we can make this a better osteoporosis treatment for eventual clinical application,” Soo said. “Not only for the millions of osteoporosis patients on Earth but also, in thinking about future space travel and a mission to Mars, we want to see how we can prevent the detrimental effects of microgravity on bones during spaceflight.”

Although modification and use of NELL-1 as a therapy has come far since its discovery more than 20 years ago, there’s still a long journey ahead before this treatment approach can be applied to humans, Ting said.

“But that’s what research is about—you have persistence and tenacity, and you never give up,” he said. “Everyone involved in the RR-5 mission was so devoted and committed to making the project successful, and it shows that if we all have the same goal and push forward, we can achieve anything. The sky is not the limit anymore!”

Three years ago, a two-headed worm returned from the International Space Station (ISS), and in the summer of 2017, the worm achieved internet and popular media fame when researchers from Tufts University published a paper describing the worm and other results from their ISS U.S. National Laboratory experiment.

The story behind this mutant worm, however, is even more rich than its delightfully deformed morphology. The payload that carried the famous worm and 77 of its relatives to the ISS and back inspired researchers, payload specialists, and even FedEx to take the first steps toward new scientific discoveries and processes that now  have their own successes to share, all of which was pioneered  by these first worms—planarian flatworms, that is—in space.

THE WONDER OF WORMS

Planarian flatworms have been studied since the 1800s as a model for genetics, body patterning, and neuroscience. The flatworms  have a “true brain,” unlike earthworms and other species in which the nervous system is more spread out and less well-developed.

Because of their brain’s bilateral symmetry, their genomes, and other factors, planarian flatworms are more similar to our human ancestors than some of the more derived model systems such as flies or Caenorhabditis elegans (nematodes), said Michael Levin, director of the Allen Discovery Center at Tufts. This model system is being used to understand regeneration, stem cell regulation, and behavior. The worms are also popular for drug addiction research because they have most of the same neurotransmitters as humans, so they exhibit symptoms of withdrawal and addiction to the same drugs.

Levin’s lab, however, uses the worms to study how physical forces influence body patterning, the process through which an organism ensures that cell types and body structures are properly shaped and placed during development. Planarian flatworms are a unique model for such studies because they are incredibly robust regenerators and yet they are mixaploid—their cells accumulate a plethora of mutations from constant regeneration and non-sexual reproduction.

In other words, because the DNA of planarian flatworms can diverge widely and yet their anatomy remains intact, their cellular decisionmaking is revealing novel aspects of how genetics and physics cooperate to control dynamic anatomy. Levin and his team studies the role of bioelectric signals—electrical communication between individual cells—in determining anatomy. They created the first-ever line of stable patterning mutants in planarians by editing their natural electrical signals, said Levin. In doing so, the team showed that it is possible to re-write electrical pattern memories to control anatomy.

Over the long term, understanding these processes may shed light on how biophysical dynamics are involved in the development, aging, and modification of body plans in higher organisms—and how we might use bioelectric and other signals to control cell behavior. Beyond myriad benefits in discovery science, the power to control cell fate with bioelectric signals could ultimately allow manipulation of regenerative or developmental processes involved in human health. For example, perhaps doctors could use this knowledge to accelerate wound healing, grow organs outside of the body for use in transplants, slow negative effects of aging, prevent certain birth defects, or improve treatments for neurodegenerative diseases.

WHY SPACE?

A notable player in biophysical dynamics is the geomagnetic field, or GMF. This natural characteristic of the Earth imposes a magnetic field of approximately 0.5 Gauss onto all living organisms. The GMF changes very large areas, so it may seem unintuitive that organisms sense and use it in their daily behaviors. However, experiments on plants, animals, and cells in culture show that they do sense and respond to changing magnetic fields, and some classic examples (such as migrating fish and birds) demonstrate ways in which organisms perceive and use Earth’s magnetic field lines. Despite these data, it is unknown how and why embryonic cells (like the stem cells of a regenerating planarian) sense the GMF.

In laboratory model organisms that are shielded from the GMF by metals and other techniques, “all kinds of things go wrong,” Levin said. “Cells are counting on this field for something, and we have no idea what.” The unique GMF conditions onboard the ISS are what prompted Levin to seriously consider an unexpected opportunity to send worms to space.

The opportunity was borne of a search for innovation. The nonprofit Kentucky Space, LLC was seeking white papers from new-to-space investigators interested in using microgravity to tackle big research questions—to spark their imagination in the early stages of the nonprofit learning how to enable research onboard the ISS.

“We heard there was this group from Kentucky that was doing some space stuff, and they were interested in sending worms to space,” said Junji Morokuma, who joined the Levin lab in late 2004 and subsequently worked on the space worms project. “I thought ‘oh wow,’ but we weren’t sure what to do or what we would find.” There was some research on worms in simulated microgravity that had shown a strong increase in regenerative capacity, he said, but there had been no planarian flatworms in space to shed light on what the team should expect.

So the team kept it simple, said Levin, and set out to determine how the combined components of space travel might affect regeneration in the worms. These components included takeoff, acceleration, splashdown, vibration, microgravity, and, of course, the altered geomagnetic field. These physical forces perturb how the cells talk to each other and thus can influence the pattern formation within cells of a regenerating worm. “It’s not zero GMF,” Levin said, as it is in ground-based shielding experiments, “but it’s different, and we didn’t have any clue what we might find.”

BREAKING NEW GROUND

As the first-ever space-faring planarian flatworms unknowingly prepared for their launch onboard commercial resupply services (CRS) vehicle SpaceX CRS-5, Kentucky Space and the Levin lab tackled a variety of their own firsts.

Kris Kimel, founder of Kentucky Space and co-founder of its for-profit spinoff Space Tango, acknowledged that early experiments like the space worms, while simple in design, played a critical role in allowing his team to “learn the ropes” with respect to payload integrations, interfacing with NASA, and dealing with customers.

“This experiment was a really important one for us,” said Kimel. “We learned a lot technically from the payload as well as how to protect the end user from some challenging processes. This experience laid the philosophical bed for what became TangoLab and our successful business ventures as Space Tango.”

Supported by CASIS sponsorship, the worms launched on January 10, 2015, spent several weeks onboard the ISS National Lab, and returned exactly one month later.

Prior to return, Kentucky Space also worked with Levin and new partner FedEx Space Solutions to arrange delivery services for the worms back to the lab following splashdown. “The logistics were really interesting,” said Levin. “I’ve never weighed a flatworm. I understand why they needed that data, but it was kind of wild.”

David Drees, who managed the flatworm delivery process for FedEx, said his primary concern was returning the worms as rapidly as possible after splashdown so the team could analyze the worms before they readjusted too much to Earth’s conditions. Some of this depended on temperature. “We needed to keep them not warm enough for cell division but not cold enough to kill them,” said Drees.

The rest was timing. “We have a great infrastructure at FedEx, but we run on schedules,” said Drees. “The capsule coming down from the ISS is not on a schedule we can predict months in advance. It could come down any time of day or night, and we’ll get maybe three hours’ notice.” To adjust to this uncertainty, resources from several FedEx operating companies were activated, and a FedEx Express courier was on standby.

Adding to the lists of firsts on the space worms’ resume, this was the first payload that FedEx executed as a “rapid return,” in which they intercept returning experiments during the handoff from launch provider to NASA, in this case at an airport on the California coast.

“It was a new thing, so I actually went out there and personally worked with Kentucky Space as they took possession of the box with the worms from the NASA plane,” said Drees. “I was a space geek growing up, so it was a really cool thing to be a part of.” From there, the box was fitted with a “SenseAware” device that sends information on location, pressure, light, moisture, and temperature to a customer web portal—and then, since it was 11 p.m., it went to a FedEx station for the night.

“Our operations folks really stepped up to handle a nontraditional shipping situation,” said Drees. “Everyone was really proud to play a small part in the experiment.” The worms’ proof-of-concept “rapid return” helped FedEx develop this service as a new product offering to its customers, with an entire system now developed for this purpose. “Space worms was the prototype!” said Drees.

A DARK AND MURKY JOURNEY

Meanwhile, back in Boston, there was a blizzard as the Tufts team waited for the new FedEx delivery process to return their box of worms from the ISS (via Long Beach, California).

Normally, the worms would routinely receive fresh water and be exposed to light when they were fed and cleaned twice a week. But to keep the initial experiment as elegant and simple as possible, none of these elements were preserved in the spaceflight experiment or ground controls. Because the goal was to evaluate regeneration, the worms were merely cut into thirds, placed into the approved container and space-certified hardware, and loaded onto the SpaceX rocket.

“We basically shoved a lot of worms into a test tube, which went into a sealed coffee-can-sized container,” said Morokuma. “Temperature was controlled to some degree, but that was it.” As promised, the postflight box arrived, and the team gathered to see whether their planaria pioneers had successfully re-grown and survived—and what stories they had to tell. “We got this box that came from space, and we were all very excited to open this box,” said Levin, “and sure enough, they were alive!”

Immediately, the team witnessed the first interesting behavior of the space worms. When they took the worms out of the dark, stagnant water from their long journey and placed them in normal water, the worms’ bodies curled. Normally, this type of curling response indicates that worms are unhappy with their environment, said Levin. “It was amazing. We put them into this beautiful, fresh Poland Springs water they normally love, they all curled up like they didn’t like it,” he said, “like they had gotten used to the stinky water—which is really strange.”

Then of course, as the team examined the individual worms more closely, they noticed the now-famous two-headed worm—which later garnered acclaim in mainstream media outlets including Gizmodo, CNET, CBS News, Fox News, Engadget, Yahoo, and Smithsonian Magazine.

Beyond being visually captivating to the public, this phenotype is statistically significant. “Planaria are robust, stable regenerators,” said Levin. “You’d have to cut thousands of these kinds of worms on the ground to see two heads.” This was the first indicator that something indeed was unique about the regenerative environment onboard the ISS.

Yet as unexpected and interesting as these early findings were, the most astounding results from the space worms study would not be seen for more than a year, when the team examined the worms’ behavior 18 months after readjusting to normal Earth conditions.

MORE THAN JUST A BOX OF WORMS

At first look after 18 months of reacclimation, the worms remarkably had a different complement of bacteria than their relatives who had remained on Earth. As with the human microbiome, the population of microorganisms in a worm’s gut, on its surface, and in its surroundings intimately influence bodily functions and behaviors.

According to Levin, until this point, no one had really studied planarian flatworm microbiomes—though some studies on their immune systems and response to infection may yield insights into the role of the microbiome. Inspired by the space worm results, however, Levin and collaborators are currently finalizing the first study of the native planarian microbiome, in terms of what the complement of bacteria typically looks like in standard populations and why it matters.

The second curious and remarkable behavior of the retired space worms suggested an atypical fear of the dark. “Normally, worms dislike the light,” said Levin. “They’re sort of photophobic and try to get into as dark a corner as they can.” After 1.5 years of experiencing normal lab conditions on Earth, however, the space worms showed a notable and unusual preference for light.

“Planarian flatworms are amazing in that they are, in effect, immortal—they don’t age,” said Levin. “They have stem cells that continuously repopulate the animal as somatic cells age and die off.” Within approximately one month, most of a worm’s cells have to be renewed. Yet 1.5 years after spaceflight, after 18 such turnovers, the space worms still showed an imprint of their unique experience, moving toward and sitting in the light far more frequently than control worms.

“This is of course conjecture at this stage, but one possibility is that they remember that long,” said Levin. “Another possibility is that it’s related to the microbiome change.” Evidence of the microbiome changing organism behavior and acting as a cognitive modulator has been seen in other animals and even humans, according to Levin.

However, more studies are needed to answer these and other questions about the influence of the ISS environment on planarians.