The Glory satellite plummeted into the Pacific in 2011 shortly after lifting off from the Vandenberg Air Force Base along the California coast.
The panel's report released Wednesday found the rocket's clamshell-shaped covering over the satellite never fully opened. But the experts said they were unable to determine why. The covering surrounds the satellite as it flies through the atmosphere.
The loss of the $424 million mission was an embarrassment for NASA, which similarly lost another climate satellite in 2009.
The rocket was a Taurus XL from Orbital Sciences Corp.
NASA only released a summary of the accident report, citing U.S. security regulations and proprietary company information.