Tepco believes the robot endured approximately 650 Sieverts of radiation per hour if it only lasted a couple of hours. If it were a human in there, he would have died instantly. The team decided to pull the robot back when its cameras went dark before losing it completely.

Since the machine wasn't able to complete its mission of doing recon and cleanup for Tepco's second robot, the follow-up machine will have a lot more to do. That is, if the team even decides to deploy it -- officials said they have to study the outcome further before deciding. The good news is that even though the radiation levels inside the reactor are extremely deadly, the team didn't find any leaks that could pose a risk to anyone outside.