Sfera (satellite)
Sfera (TEKh-44) is a small passive satellite deployed during a spacewalk from the ISS in August 2012.

Description
Also called the Vektor-T calibration sphere, the satellite enables operators to track its movement, generate velocity and acceleration estimates to determine to what extent atmosphere is slowing down the sphere as it travels in space. Drag (velocity deceleration) estimates are used to determine localized atmospheric density. 

TEKh-44 is a shiny sphere 53 cm (20.8 inches) across weighing 14 kg (~31 pounds). "Sfera" is Russian for sphere.

Re-entry
It  re-entered the atmosphere in late November 2012.

See also
List of passive satellites

References

External links
Sfera deployed

Passive satellites
Spacecraft which reentered in 2012
Spheres
Atmospheric sounding satellites