Making the Invisible Visible: The Remarkable Journey of a Powerful Space Microscope

Colloids are mixtures of microscopic particles suspended in fluids, partly solid and partly liquid substances. Colloids are found in products such as toothpaste, ketchup, paint, and liquid hand soap, and are part of a field of study known as soft matter.

Another familiar experience with colloids: “settling,” which is when these mixtures separate into layers over time, separated by gravity. That’s why researchers set out to study how these substances behave at a fundamental level in space, in order to extend the “shelf life” of materials, both in space and on Earth.

To collect this data, the researchers needed a special tool that would allow them to see deep into the world of these tiny particles. Enter NASA’s LMM, the optical microscopy module.

Since 2009, scientists and researchers from six countries, including 27 universities and research organizations, have spent thousands of hours using the remarkable power of this state-of-the-art light-imaging confocal microscope facility to study a variety of physical phenomena. and biological. Formerly housed in the Destiny module of the International Space Station, the LMM has greatly contributed to scientific discovery.

The LMM has been used by private companies to find new ways to improve their consumer products. Procter & Gamble, for example, received approval on three patent applications for new products directly derived from company research using the LMM.

The device has also helped other engineers design the next generation of highly efficient quantum dot-responsive devices. solar cellsdramatically improve biomedical device technology and offer potential innovations in materials of construction for use on Earth, the Moon, and Mars.

Diane Malarik is currently the Deputy Director of NASA’s Biological and Physical Sciences Division, but in the 1990s she was the project manager responsible for the initial design of the LMM. As she recalls: “We designed payloads for the spaceship, but then they had much simpler designs and operation. The equipment was designed to be used only once by a single investigator. When the idea of ​​building an LMM to be installed on the space station came up, we knew it would need to be used by at least four investigators and we had to design it with a lot more flexibility.”

Since its installation, the LMM has been used in 40 experiments, capturing essential images to help scientists and engineers understand the forces that control the organization and dynamics of matter at microscopic scales. Indeed, the LMM has helped to make the invisible world of colloids more visible.

What made the LMM unique among microscopes was that it allowed scientists to use the microgravity environment to observe the separation of physical and biological mechanisms over much longer time scales than possible on Earth. . And the microscope’s high-quality three-dimensional images have deepened our scientific understanding of multiple micro and macroscopic fields, including heat transfer, colloidal interaction and phase separation. In doing so, it has enabled scientists to improve the efficacy of commercial products on Earth and has contributed to the scientific community’s understanding of colloids.

After more than a decade of research, the last LMM experiment took place in October 2021. During this time, the LMM has been used for research on soft matter/complex fluids (colloids and gels), physics of fluids (heat pipes), biophysics (protein crystallization, drug delivery) and plant biology (sensing gravity in roots). More than 30 conference presentations have been given and about 50 publications in journals published or in development use data directly from the results of the space station LMM.

Museum professionals hope that one day the LMM can be preserved so others can interact with it on Earth as well. Lauren Katz, NASA artifacts and exhibits program manager, said she would be happy to oversee the potential use of LMM in future NASA exhibits and museum loans. “We believe the inclusion of the LMM could serve as a fascinating introduction to how science in space can be conducted from Earth,” says Katz. “Additionally, as the microscope is remotely controlled, we think this interactive feature could serve as a ‘cool’ factor as visitors control the microscope (or representative device) themselves.”

Many factors will influence the ability of the LMM to be returned to Earth, namely space constraints on board both the space station and return vehicles. Whatever the LMM’s final destination, its legacy as a workhorse for science will remain.