A second runway was added crossing the original north-south landing strip, and in 1979 both lakebed runways were lengthened to 35,000 ft (10,668 m), which includes 15,000 ft (4,572 m) usable runway with 10,000 ft (3048 m) extensions on either end, to allow White Sands Space Harbor to serve as shuttle backup landing facility.
An auxiliary runway was added crossing the original runway, and in 1979 both lakebed runways were expanded to 35,000 ft (10,668 m), including a 15,000 ft (4,572 m) operational section with 10,000 ft (3048 m) additions on either side, allowing White Sands Space Harbor to serve as a backup landing facility for space missions.