On April 2525, the vessel went on patrol in the Lambda Serpentis system. Unknown to most of the crew, the SPARTAN-IIs were aboard for this mission, to recover from their augmentations - and bury their dead - in the microgravity atmosphere.
The Atlas had a detachment of ODSTs from the 105th Orbital Drop Shock Trooper Division. One morning, in the Atlas gym, an argument between John-117 and four ODSTs was caused by John accidentally almost crushing an ODST's foot with weights, which escalated into a fight, leaving three of the ODSTs dead and one badly wounded. The result of the fight was observed by Second Lieutenant Antonio Silva, and permanently marred by the relationship between Spartans and ODST contingents.