You never know what you’ll discover when you remove gravity from the equation, which may be why researchers find investigations aboard the International Space Station (ISS) so compelling.
Three individuals representing their teams accepted honors in Top Discoveries in Microgravity June 19 for their work as they highlighted research during the fifth plenary panel at the third annual ISS Research and Development conference:
Mitsuteru Sato, Ph.D., Hokkaido University, Sapporo, Japan, in recognition of top results for the Global Lightning and Sprite Measurements on the Japanese Experiment Module Exposed Facility (JEM-GLMIS): First Qualitative Nadir Observations of Lightning and Transient Luminous Events (TLE).
Rohit Trivedi, Ph.D., Iowa State University, in recognition of top results for breathing modes in cellular interface pattern formation in directional solidification, carried out in the Device for the Study of Critical Liquids and Crystallization-Directional Solidification Insert (DECLIC-DSI).
Kim de Groh, NASA's Glenn Research Center in Cleveland, in recognition of top results for Materials International Space Station Experiment (MISSE) Collaboration for Materials Testing on ISS.
“These investigators bring fantastic results from studies that are leading to new spacecraft materials and designs and ways to search outside our planet in hope of leading to fundamental discoveries," said Allyson Thorn, NASA ISS Research Integration at the agency's Johnson Space Center in Houston and a member of the award committee. "We are excited and motivated by these new findings, helping our quest, turning the unknown into the known."
This year’s conference themes are discoveries, applications and opportunities. Specifically, discoveries in microgravity, space and Earth science, as well as engineering and education; applications benefitting Earth, enabling technology and advancing exploration; and opportunities for use of this innovative laboratory. The conference takes place June 17 to 19 in Chicago.
JEM-GLMIS is a space mission that observes lightning and lightning-associated optical flashes from the station known as Transient Luminous Events (TLEs), such as sprites and elves. Sprites appear high in the atmosphere, miles above thunderstorms, with twisted structures that extend down as far as 25 miles. They are normally associated with positively charged cloud-to-ground lightning strikes. Elves are electromagnetic pulses caused by lightning strikes.
From the optical and electromagnetic observations of JEM-GLIMS with the nadir viewing from the station, it is possible to identify the physical parameters determining the occurrence location of sprites over the sprite-producing lightning discharge. Nadir is the lowest point or level. JEM-GLIMS observations contribute to a more quantitative understanding about the effects of sprites on Earth’s ozone layer.
"The time period to develop and fabricate our JEM-GLIMS instruments was quite limited,” said Sato. "During the development and before the launch, in 2011, we had a big earthquake that affected our overall development plan. At that difficult time, we could not imagine today’s success. However, we led ourselves with willpower and strong teamwork, and, of course, with full support from the Japanese Aerospace Exploration Agency. This award gives us confidence, and it becomes an important milestone that pushes us to strive for more new scientific results."
The results found by Trivedi and his team have direct impacts on Earth. DECLIC is used to study crystal growth in transparent liquids. The DSI portion of DECLIC observes clear alloys that freeze like metals in microgravity. By providing real-time views of the crystal structures that form in the liquid, DECLIC-DSI sheds light on the physics that control the formation of solid materials.
Solidification processing is important in the manufacturing of critical industrial products that range from many automobile parts to turbine blades for jet engines. Although the transformation of liquid to solid is a simple concept, the manner in which this occurs is very complex, as exemplified by the variety of snowflake structures that form in the atmosphere. This area of research establishes the fundamental science that governs the formation of complex structures that evolve during solidification so that precise conditions can be designed to manufacture objects with superior properties and high reliability.
"Our results show that under some growth conditions, cells do not grow with a constant cross-section, but the cross-section oscillates with time, increasing and decreasing cross-sectional areas that resemble the breathing process," said Trivedi. "This award is special because it encourages us to look for other new phenomena that are present during solidification."
MISSE investigates the effects of long-term exposure of materials to the harsh space environment. It has provided a platform for environmental durability studies for many devices and thousands of samples, and it has produced tangible impacts. MISSE-1 through MISSE-8 have flown, yielding long-duration space environmental performance and durability data that enable material validation; processing recertification and space qualification; improved predictions of materials and component lifetimes in space; model verification and development; and correlation factors between space-exposure and ground facilities. Results have impacted the operational durability of the station, Earth-observing satellites and other spacecraft.
"MISSE is a collaborative effort with participants from NASA, the Department of Defense, industry and academia," said de Groh. "There have been hundreds of contributors from more than 85 organizations over the past 15 years. This award is graciously accepted on behalf of all participants of the MISSE project. Each participant has made a valuable contribution, and we all share in this wonderful honor."
MISSE 2 PEACE (Polymers Erosion and Contamination Experiment) is one example of the hundreds of successful MISSE experiments. This study determined the long duration low-Earth orbit atomic oxygen erosion yield of 38 polymers. Erosion yields are needed by spacecraft designers to ensure the survivability of materials exposed to atomic oxygen in the low-Earth orbit environment.
Additional award categories for the conference include: Most Compelling Results from the ISS in 2013; Biotechnology, Health and Education; and Engineering Development and Technology Maturation with a Focus on Commercial Applications and Exploration Applications. The American Astronautical Society organized the event in cooperation with the Center for the Advancement of Science in Space (CASIS) and NASA. The yearly gathering is the only U.S. conference to detail the scope of research and technology development on the space station.