It's back on. Two weeks after the space shuttle Endeavour's launch was postponed due to electrical problems, it's scheduled to launch on Monday morning. Rep. Gabrielle Giffords is once again expected to watch as her husband, Mark Kelly, commands the Endeavour's final mission. Giffords travelled to Florida on April 29 to watch the launch, but it was canceled at the last minute. Her ability to make a second trip so soon is an indication of the rapid pace of her recovery. The second launch isn't expected to draw the estimated 700,000 spectators that the first one was expected to, in part because President Obama won't be attending the rescheduled launch. The astronauts will deliver a $2 billion particle physics detector and conduct four space walks.