DARPA updated its humanoid rescue robot Atlas, but the changes show how far the machine still has to go to be useful in disaster zones. Atlas will be used by up to seven teams in the DARPA robotics challenge later this year. The competition is aimed at developing robots that can help humans respond to natural and man-made disasters. Among the upgrades is a variable pressure pump that will help the robot conserve energy and also make it a lot quieter. Unlike previous versions of the robot this one can run completely on batteries, albeit not for very long. Its 3.7 kilowatt hour lithium ion battery will give it about one hour of mixed mission operation. That's far from what would be required to tackle a real-world emergency where there are no means to recharge. The new bot has three computers for processing sensor input for task planning as well as wireless communication abilities. During the challenge it will face communication blackouts of up to one minute and it will need to operate autonomously. Three and a half million will be award to the top three finishers in the challenge. In Boston, Nick Barber, IDG News Service.