A pair of CubeSats, with the Earth's limb in the background, moments after being ejected from a small satellite deployer outside of the International Space Station's Kibo laboratory module on Wednesday, May 16, 2017.

The tiny shoebox-sized satellites will orbit Earth observing the Earth's upper atmosphere and interstellar radiation left over from the Big Bang.

Over a dozen CubeSats were ejected into Earth orbit this week outside the Kibo module to study Earth and space phenomena for the next one to two years.