VANDENBERG AIR FORCE BASE, Calif. — NASA has delayed the launch of a sun-observing satellite by a day so that technicians can restore power to launch range equipment.

The Iris satellite was supposed to be carried aloft from California's Vandenberg Air Force Base on Wednesday. But the launch range recently lost electricity after an equipment failure at a utility substation darkened much of the central coast. The problem is expected to be fixed by Thursday evening.

Iris will ride into Earth orbit aboard a Pegasus rocket, which will be dropped from an airplane flying over the Pacific. Once in place, it will point its ultraviolet telescope at the sun.

It's the latest satellite designed to gaze at the sun in an effort to better predict space weather, which can affect communication systems on Earth.