The 420K's envelope shape, fin design, and cable attachment points are further optimized for high aerodynamic stability and easy ground handling. While Lockheed Martin is the prime contractor for the 420K aerostats, the envelopes are built by ILC Dover.
The 420K's envelope shape, fin design, and cable attachment points are further refined to enhance high aerodynamic stability and simple ground maneuverability. Although Lockheed Martin is the primary contractor for the 420K aerostats, the envelopes are constructed by ILC Dover.