Martin Jetpack hits the 5,000 feet milestone, could come to market within 18 months

OK, so the Martin Jetpack may not have gone into commercial production quite as soon as we'd anticipated, but there's still hope on the horizon. Over the weekend, Glenn Martin's flying machine successfully climbed some 5,000 feet above sea level, marking a new milestone in the 30-year, $12 million project. Remotely controlled by a tailing helicopter, the 250-pound craft used its two "superfans"