Hallsley knew about the Spartan 1's, and why they weren't overly succesful, which is why/how she adapted her Spartan 2 program to require the genetic enhancments and other modifications. It was believed that there weren't any surviving Spartan 1's after Harvest. As we all know know, but haven't yet learned how, Johnson (who was a Spartan 1) somehow survived and was re-enlisted as a "standard" soldier. [Edited on 06.21.2007 12:10 PM PDT]