Feb. 6, 2018

Space Station Science Highlights: Week of Jan. 29, 2018

NASA astronaut Joe Acaba works with the SPHERES satellite as part of the SmoothNav investigation.
NASA astronaut Joe Acaba works with the SPHERES satellite as part of the SmoothNav investigation.
Credits: NASA
NASA astronauts Joe Acaba and Mark Vande Hei prepared for the SmoothNav investigation last week.
NASA astronauts Joe Acaba and Mark Vande Hei prepared for the SmoothNav investigation last week. This investigation develops an estimation algorithm aggregating relative state measurements between multiple, small, and potentially differently instrumented spacecraft.
Credits: NASA
Cosmonauts Alexander Misurkin (left) and Anton Shkaplerov in their Russian spacesuits before a Feb.2 spacewalk outside ISS
Cosmonauts Alexander Misurkin (left) and Anton Shkaplerov are pictured in their Russian Orlan spacesuits during a fit check ahead of a Feb.2 spacewalk for International Space Station maintenance
Credits: NASA
Last week, the crew living and working aboard the International Space Station had a busy week of science and spacewalk preparations, as well as an early Friday morning spacewalk for Russian crew members.
Crew members explored research in the fields of physical science, technology demonstrations and human research. Take a more detailed look at some of the science that happened last week aboard your orbiting laboratory:
Crew prepares ELF for upcoming operations
The Electrostatic Levitation Furnace (ELF) is an experimental facility designed to levitate, melt and solidify materials by container-less processing techniques using the electrostatic levitation method. With this facility, properties of high temperature melts can be measured, and solidification from deeply undercooled melts can be achieved. 
Last week, the crew moved samples to prepare for upcoming ground commandedoperations. Results from this investigation may contribute to the development of containerless processing technology, benefiting manufacturers and scientists designing new materials.
Crew conducts trial run for SmoothNav investigation
Many future space exploration and space-based business enterprise models, such as on-orbit satellite servicing, on-orbit assembly, and orbital debris removal, necessitate the use of fully autonomous multi-satellite systems. Smoothing-Based Relative Navigation (SmoothNav) develops an estimation algorithm aggregating relative state measurements between multiple, small, and potentially differently-instrumented spacecraft.
The algorithm obtains the most probable estimate of the relative positions and velocities between all spacecraft using all available sensor information, including past measurements. The algorithm remains portable between different satellite platforms with different onboard sensors, adaptable in the case that one or more satellites become inoperable, and tolerant to delayed measurements or measurements received at different frequencies.
Last week, the crew set up the work area to activate and check out the hardware before conducting a trial run.
Investigation tests lighting aboard space station
Anyone who uses electric lights can benefit from lights that can be adjusted for intensity and wavelength across the day, improving alertness during waking hours and promoting sleep during evening hours. The Lighting Effects investigation studies the impact of the change from fluorescent light bulbs to solid-state light-emitting diodes (LEDs) with adjustable intensity and color and aims to determine if the new lights can improve crew circadian rhythms, sleep and cognitive performance.
Last week, the crew conducted a visual performance test by stowing the hardware in their crew quarters, setting the light to the correct mode, turning all other light sources in the crew quarters off, and performing a color discrimination test.