CAPE CANAVERAL, Fla. -

Af­ter four launch attempts in four days, a Delta IV rocket and three military satellites remain right where they started -- on the launch pad.

But after a day off Sunday to give the launch team a break, United Launch Alliance and the Air Force will take anoth­er shot Monday, when the weather is expected to im­prove a bit. Launch on Monday is targeted for 6:43 p.m., the opening of a 65-minute window at Cape Canaver­al Air Force Station.

There's a 60 percent chance of favorable weather -- the best odds yet since the mission be­gan trying to get off the ground on Wednesday.

Technical problems scrubbed the first try, but thunderstorms and light­ning washed out the next three countdowns on Thursday, Friday and Sat­urday.

There was some opti­mism the storms might clear before Saturday's window closed at 7:56 p.m., but a lightning warn­ing never cleared. Several funnel clouds were spotted, and the Titusville area was under a tornado warning for about 30 min­utes in the hours leading up to the launch window.

With the day off, the 206-foot Delta IV and its payload were returned to the shelter of a mobile ser­vice tower at Launch Complex 37. Atop the rocket are twin satellites that will look out for threats from other spacecraft orbiting more than 22,000 miles up, and a third experimen­tal satellite.

The mission's delay to Monday has pushed back by one day, to Friday, the next launch on the Cape schedule: an Atlas V rock­et carrying the seventh in a new series of Global Po­sitioning System satel­lites. That launch is now planned at 11:23 p.m. Friday, with an 18-minute window.