Underground day 2.

The cavenauts explore more of the Sa Grutta caves and set up a communication line.

An international crew of six astronauts are training for a caving adventure designed to prepare them for spaceflight. There are many similarities to spaceflight such as a lack of day--night cycle, sensory deprivation, minimal hygiene and the necessity to work as a team and solve problems together.

After a week of training they entered the caves to spend six days living and working underground.