By Mike Schneider THE ASSOCIATED PRESS

CAPE CANAVERAL, Fla. – For the second day in a row yesterday, NASA scrubbed the launch of an unmanned spacecraft on a nine-year voyage to Pluto – this time, because a storm in Maryland knocked out the power at a laboratory that will operate the probe.

NASA officials planned to make a third attempt to launch the New Horizons probe today after electricity was restored to the lab.

High winds at the launch pad kept the spacecraft from lifting off Tuesday, the first day the launch window opened.

Scientists have been working 17 years on the mission, and they were unfazed by the back-to-back postponements.

“Two or three days doesn’t mean a hill of beans,” said Alan Stern, principal investigator for the mission.

A storm in Laurel, Md., knocked out power early yesterday at the John Hopkins University Applied Physics Laboratory.

“The air conditioning was off. The flight controllers were sitting there wiping sweat,” Stern said. “If they were dealing with any spacecraft issues, which first day out of the box a lot of spacecraft have, you can’t concentrate like that.”

The space agency has until mid-February to send the spacecraft on its way, but a launch in January would allow the spacecraft to use Jupiter’s gravity to shave five years off the 3-billion-mile trip, allowing it to arrive as early as July 2015.

The spacecraft is about the size and shape of a concert piano. It will study Pluto as well as the frozen, sunless reaches of the solar system known as the Kuiper Belt. Scientists believe that studying the region’s icy, rocky objects can shed light on how the planets formed.