Another experiment enabled through this resupply mission is the
Comparative Real-time Metabolic Activity Tracking for Improved
Therapeutic Assessment Screening Panels investigation—a study
using a new method to track the metabolic activity of cells and the
effects of five therapeutic compounds on those cells in microgravity.
Previous research has found that microgravity can alter the way
drugs interact with human tissue, and has opened up the possibility
of drug discovery and development in space—which can even result
in more effective and less expensive medications. This experiment
will investigate the use of autobioluminescence to track metabolic
activity in microgravity in real-time, without having to destroy the
A synthetic luciferase gene is combined with human embryonic kidney cells, which emit a certain amount of light correlating
to their metabolic activity. By observing this bioluminescence,
researchers will track the effect of the five compounds on the tissues.
Samples on Earth will be compared to samples on the ISS to further
assess the impact of microgravity on this process.
This research, in addition to assessing the potential of drug
development in space, can also lend insight into emergency medical
treatment for astronauts on missions.
Materials in space
Testing a variety of materials in space has been one long-running
objective of the International Space Station’s research—since 2001,
the ISS has been working on a project called the Materials International Space Station Experiment (MISSE), beginning with MISSE 1
and 2 that were attached to the outside of the station on Aug. 10,
2001. The objective of these missions was to observe how different material structures, coatings, electronic components and more
would fare on the exterior of a spacecraft, exposed to various types
of radiation, highly reactive atomic oxygen, thermal cycles and an
ultra-high vacuum environment.
With the arrival of CRS- 14, ISS scientists received new MISSE
samples—and the new MISSE-FF (Flight Facility) that will allow for
closer monitoring of the tested materials than ever before. While the
previous MISSE missions—MISSE 1 through 8—mostly involved
planting the materials outside of the station and retrieving them after
a long period of time to see how each fared, this facility includes components called MISSE Sample Carriers (MSCs) that provide monthly
images of the materials to the researchers, as well as on-demand data.
Additionally, the MSCs do not require the astronauts to leave the
space station to plant or retrieve them. The MSCs are attached via
one of 12 “slots” on the MISSE-FF, and can be retrieved using the
same robotic arm—the Canadarm 2—used to bring in the Dragon
capsule. Scientists control the MSCs remotely from Earth—the ISS
astronauts simply need to load and later retrieve them, and prepare
them to be returned to Earth for further study.
Once the samples are sent back to Earth, researchers can observe
any erosion that may have occurred to the palette of materials—
the results to inform engineers designing future spacecraft. The
MISSE- 9 samples include 138 different materials, which will be
left in orbit for about a year. In addition to the overall effects of
different space conditions like radiation and temperature on the
materials, this experiment will also look at how flight orientation—
the position of the materials relative to the direction of the station’s
movement—affects the materials.
“We will fly some of the same materials in different orientations
as the same material can react differently in each flight direction,”
Seeds are planted in the veggie Passive Orbital Nutrient Delivery System
(PONDS) units inside a laboratory at the Space Station Processing Facility
at NASA’s Kennedy Space Center in Florida. Photo: NASA/Daniel Casper
said Kim de Groh, senior materials research engineer at NASA’s
Glenn Research Center, when explaining the experiment.
Thunderstorms from above the clouds
In addition to its novel microgravity and thermospheric conditions, the ISS is also in a unique position to observe Earth from
above. The Atmosphere-Space Interactions Monitor (ASIM) supplied by CRS- 14 will do just that, tracking Earth’s upper atmospheric lightning patterns to strengthen scientists’ understanding of the
atmosphere and potentially provide insight into the planet’s climate.
The ASIM observatory will be installed on an external platform on
the European Space Agency’s Columbus module of the ISS.
Upper atmospheric lightning is different from most lightning
observed from Earth’s surface during normal thunderstorms—these
transient luminous events involve electrical discharges in the stratosphere and mesosphere, high above the altitude of typical storm
clouds. This lightning can take a variety of different forms, including sprites, large electrical discharges in the mesosphere; blue jets,
which discharge up from the tops of clouds into the stratosphere;
and ELVES (Emissions of Light and Very Low Frequency Perturbations due to Electromagnetic Pulse Sources), large concentric light
rings occuring in the lower ionosphere.
The ASIM will monitor these phenomena using its cameras,
photometers, X-ray detectors and gamma-ray detectors to observe
the processes of these different luminous events and possibly help
scientists understand their role and impact on other atmospheric
processes and the climate. Overall, these observations will help build
a more comprehensive atmospheric mode that can be applied to
climatology, meteorology and environmental studies.
What goes up must come down
SpaceX’s Dragon capsule is scheduled to return to Earth in May,
bringing back approximately 3,500 pounds of research material as
well as additional hardware and supplies. CRS- 14 will also return
with Robonaut 2, a robot that has helped ISS crew members with
various tasks since 2011, and is in need of repairs.