Echo II, a Balloon Satellite
Echo II is shown here undergoing a tensile stress test in a dirigible hanger at Weekesville, North Carolina. A dirigible is a type of aerostat or "lighter-than-air" aircraft. The 135-foot rigidized balloon satellite was sent into orbit as a passive communications experiment by NASA on January 25, 1964.
When folded, the satellite was packed into the 41-inch diameter canister shown in the foreground.
Image Credit: NASA