Since we have more and more requirements for LTA flying at high altitudes, we started introducing the latest ultrasonic technology in joining parts of the envelope as well as joining various assemblies on the envelope. We expect to fully adopt and accept the technology and start regular production by the summer. So now we have at our disposal 3 types of technology for joining envelope parts/components: Classic with active glue (-10 to +70 C) G, thermal (-20 to 100 C) and the latest ultrasonic (Limited by the characteristics and quality of the material) . As it turns out, each height has its own corresponding technology.