WASHINGTON — NASA and the National Academy of Sciences are joining the government's effort to figure out what caused the sudden acceleration problems that led to Toyota's massive recalls.

NASA scientists with expertise in electronics will help the National Highway Traffic Safety Administration study potential electronic ties to unintended acceleration in Toyotas. NASA's knowledge of electronics, computer hardware and software and hazard analysis will ensure a comprehensive review, Transportation Secretary Ray LaHood said Monday.

In a separate study, the National Academy of Sciences will examine unwanted acceleration and electronic vehicle controls in cars from around the auto industry, LaHood said. The National Academy is an independent organization chartered by Congress.

The academy study, expected to take 15 months, will review acceleration problems and recommend how the government can ensure the safety of vehicle electronic control systems.

Toyota has recalled more than 8 million vehicles worldwide, including 6 million in the United States. Toyota said in a statement it was "confident in our vehicles and in our electronics" and would cooperate with the government review.