Discovery's launch to the International Space Station is now scheduled for Tuesday afternoon -- Election Day.
NASA test director Jeff Spaulding said if the latest repairs go well, the agency will press ahead with a Tuesday launch, even though it's Election Day. Considerably more launch spectators than usual are anticipated, since this will be Discovery's 39th and final liftoff as the shuttle program winds down. Coupled with Election Day traffic, the roads almost certainly will be jammed.
For weeks, managers have been encouraging workers to vote early or by absentee ballot, just in case a launch attempt fell on Tuesday. Florida, like many other states, allows voting before Election Day.
"That was something that we recognized a long time ago, the possibility for the dates to line up could be a realistic event," Spaulding told reporters. "We want to make sure everybody has the ability to vote" without worrying about getting to the precincts on Tuesday.
The Discovery's six astronauts cast ballots before leaving their Houston homes. They arrived at Kennedy Space Center on Thursday.
Engineers have traced the leaks to couplings, or connection points, in the helium and nitrogen lines for the system used to maneuver the shuttle in orbit, back near the shuttle tail.
Spaulding said he's confident the faulty couplings can be replaced in time for NASA to begin the launch countdown on Saturday. These types of hookups have a history of breaking and leaking, and technicians have replaced them many times in years past at the launch pad, he said.
Discovery is loaded with a pressurized compartment full of supplies and even a robot for the space station. The mission is expected to last 11 days. It's the next-to-last shuttle flight scheduled, although an extra mission could be added.
Forecasters put the odds of good flying weather Tuesday at 70 percent. Launch time will be 4:17 p.m.
NASA has until Sunday to launch Discovery, otherwise the mission will have to be put off until December at the earliest because of unacceptable sun angles.