Astrea

Astrea (アストレア Asutorea) is a planet surrounded by chunks of rock.

Galaxy Force cartoon
Before the threat of the Grand Black Hole existed, Wing Saber and Optimus Prime were involved in a rescue mission by Astrea. Under desperate pressure to save the life of a spacefarer, they flew back-to-back with each other in an attempt to escape the debris and get the spaceman to safety. Wing Saber was thrown off from formation and nearly collided with a huge rock, but was apparently saved by Prime.