The interior of Zero G 727 is mostly made up of leather padding. Synthetic padding is not used as per FAA in case of onboard fire. Zero G is a neat 727 that takes you up to 32,000 feet and then does dives and climbs which simulates weightlesness. NASA sends their people on flights and I'm told that civilians can also go, the cost is $3,000 per person (not sure how long the flight is)