EDWARDS AIR FORCE BASE, Calif. (AP) _ A NASA research plane and close cousin to the U-2 spy plane set a new altitude record for a medium weight aircraft by soaring to 68,700 feet, almost twice the cruising altitude of most commercial jetliners.

The ER-2 aircraft based at the Dryden Flight Research Center made the historic flight Thursday during an Airborne Science mission designed to measure water, ozone and other particles in atmosphere, Dryden spokeswoman Kirsten Williams said.

The flight surpassed the 62,500 feet flown by a Canadian P-42 aircraft in 1988. A medium weight aircraft ranges from 26,455 pounds to 35,274 pounds at takeoff.

It wasn't the first time the ER-2 reached the high altitude mark, but it was the first time the ER-2's performance was documented and made public. A National Aeronautics Association official observed the record-setting flight and will process formal certification.