MSE at the Dawn of the Space Age

contributed by
Leslie R. Hodges
B.S. CERE 1957

After graduating from Georgia Tech, I was employed at the Georgia Tech Engineering Experiment Station, Ceramic Department. I was assigned as engineer in charge of development of permanent foundry molds. I believe sand molds were the standard at that time.

That year the Sputnik was beeping overhead and a contract was obtained from Redstone Arsenal for ablative nose cones for supersonic re-entry of intercontinental missiles.  Our compound was room temperature to 1000 C with zero thermal expansion.  This particular compound had marginal strength, and during a meeting, it was suggested we try some additive.

A compound was formulated with an additional 5% Kentucky Old Mine # 8 ball clay. The strength doubled with no change in thermal expansion.  After a few modifications in mold design, we were able to fabricate a quite impressive nose cone to their specifications, including molded threads for mounting.

Georgia Tech Engineering Experiment Station 1957 article caption read “Rocket nose cones of Tech’s new ceramic material successfully cast in molds” Click here for the complete article

We took the test nose cone to Redstone Arsenal and were directed to a butler building on the reservation. The building contained a V-2 static mounted rocket engine, with an accompaniment of German technicians. The exhaust of the rocket was outside the building.  We mounted the nose cone on a fixture which was behind a huge V shaped block of carbon.

They directed us to about the third rolling hill (50 yards) and suggested we lie on the grassy turf to observe the test. The rocket was fired and when the engine was burning properly, they lifted the carbon block.  The exhaust from the V-2 simulated re -entry conditions. On a number of occasions, I observed the amazement of those who observed the properties and the success of this compound.

I left the Station after only one year to pursue electronic ceramics but while I was there, we made nose cones up to three feet.  This compound is presently on missiles.  The shuttle tile compound is not published but probably the same compound with different forming techniques.  I was jolted when recently one of the engineers reporting on the shuttle tile said, “and it contains some clay.” I still remember the compound, which was composed of fused silica, colloidal silica and clay.  Simplicity at its best!

Some years back, I visited an aircraft company in Orlando, Florida and was shown inside a three-acre building with many large, bottom load furnaces.  Around the edges of the building were broken six-foot tall nose nones.  The engineer explained that they had a contract for nose cones but it had been cancelled due to their inability to remove the casting from the plaster molds.  Colloidal silica had locked the castings in the pores of the plaster molds.  Of course, this problem was solved at the Experiment Station in 1957. Lost technology can be very costly!

Leslie R. Hodges
B.S. CERE 1957

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