The launch, which had already been called off Sunday, was delayed to 1:58 pm (1758 GMT) Tuesday with a second window at 2:36 pm (1836 GMT) after a Monday afternoon launch was scrubbed.

MER-A is to be launched aboard a Boeing-made Delta II launcher from Cape Canaveral, Florida. It will travel some some 500 million kilometersmillion miles) over seven months, then drop into the Gusev crater, 15 degrees south of the Martian equator, in early January 2004.

A second Mars Rover, MER-B, is scheduled for launch on June 25 and is due to land exactly one year later in an area of Mars known as the Meridiani Planum.

Forecasters predict a 30 percent chance of rain during Tuesday's launch window.

SPACE.WIRE