What was this strange design for the Man In Space Soonest program?

Question

The following picture shows various spacecraft design proposals for the 1958 U.S. Air Force Man In Space Soonest program:

The bottom row depicts various spaceplanes, which should not be a surprise considering that many of the companies involved were established aviation manufacturers. The top row shows three conical designs (similar to what was finally chosen for Mercury), then a bullet-shaped capsule (like Soyuz), then dear lord what is that?!, and finally two spherical capsules (like Vostok).

Are there any details on the Avco design?

I realize that Avco later made the Apollo heat shields. Were they trying to make a capsule that was 70% heat shield?

Is it swamp gas?

Answer 1

Not a heat shield, but rather a steel-mesh parachute of sorts.

From This New Ocean:

...the contractor team of Avco and Convair, which, since the Sputniks, had spent more time and money on manned satellite design than other industrial firms, presented to the Air Force a highly detailed proposal for development of a "minimum" vehicle. Featuring the "bare" Atlas, the basic "one and one-half stage" ICBM with no second stage, the Avco-Convair approach would orbit a man inside a sphere weighing 1500-2000 pounds. The steel-mesh drag brake, a metallic, inverted parachute, would be used for atmospheric entry.

There's more information on the Avco project on Astronautix (grain of salt not included). If I'm understanding correctly, the drag brake would be inflated with compressed air and the induced drag would actually begin the re-entry process, rather than relying on a retrorocket! This would obviously only work at a quite low orbital altitude.