Major John Sheppard's team, while exploring the planet, discovered the truth about their protection, and Dr. Rodney McKay, having determined that the ZPM was too depleted to power Atlantis for more than a few hours, was able to expand the field without a significant power loss. Later, Dr. Radek Zelenka was sent to help repair the field, and appeared to have been accepted into the tribe. In 2008, the device had further troubles. (SGA: "Childhood's End", "Critical Mass", "Outcast")