While I had thoroughly enjoyed my career life of 40-odd years working in aircraft engineering, there was always an inner desire to have a role in the US Space Program – so when Charlie XXXX, President of Rockwell’s Space Division, called to say that he needed someone with my background for his Space Shuttle’s difficulties, it struck a responsive chord. After a week or so thinking about it – talking it over with family (significant salary reduction) – I accepted. And so I became Assistant Chief Engineer at Rockwell’s Space Division, in charge of Engineering for the vehicle, except for engines and computers.
I quickly learned why the Shuttle was so far behind schedule. NASA had set for itself, a clearly, highly improbable goal – to provide thermal protection against 3000 degree re-entry heat – for an entire airplane – with all conventional and standard components and equipment items, such as wings, flaps, tail, ailerons, etc., and including wheels, brakes and tires. Everything required insulation protection! The basic problem was trying to obtain perfect vacuum insulation consistently – in 33,000 fragile tiles.
At the outset of NASA’s Space Shuttle program, it had been deemed essential that a more sophisticated solution to re-entry-heat be found than was used for the US Moon program. Its basic structural configuration had been missile technology, circular cylinders for fuel tank stages and rocketry, also for the Escape-Recovery Capsule. For the dangerous re-entry back to Earth insulation what been provided – simply but effectively – by five inches of cork attached to the bottom of the Escape-Recovery-Capsule. On re-entry, “charring” insulated the Astronauts and Capsule from the intense heat. After reentry, three parachutes on the Astronaut Capsule were opened, lowering it to the ocean surface – and rescue ships.
Thermal insulation for the “Space Shuttle” vehicle, however, had to be considerably more reliable and sophisticated than thick cork. Desired was an “airplane-type” of space-craft, capable of flying (gliding – no engine-power after achieving escape velocity) – to any landing field on Earth for a safe landing – “flying” via it’s post-re-entry velocity-momentum. The “forcing function” was the word “shuttle”, a vehicle system capable of re-use without inordinate repair. The need, therefore, was for absolute thermal insulation during re-entry – as could be provided only by a perfect vacuum – covering and protecting a total airplane, complete with wings, fuselage, tails, landing gear, etc. Reliability of 100% was required (or at least 99.999%) – or death and disaster would await each flight’s return.
The conceptual reliance was upon “tiles”, tens of thousands of them. All but the specially configured shapes at air-foil leading edges, were a standard size, 6 in. x 6 in. x 1.125 in. thick. The outer surface was a thin, fragile glass covering; the glass kept from cracking by “crunched” non-conductive filaments of silica, stuffed inside, providing support for the thin glass plus vacuum insulation. And each tile had to be perfectly flawless, since the harshness of Space was completely unforgiving! To this end, each tile was double vacuum-ized.
And to this end also, continuous, meticulous inspection procedures were inaugurated – and continually improved upon – with a system of detailed inspection and repair processes) The installation of the tiles on the Shuttle surface was equally meticulous and painstaking – “gap-fillers” of quartz fibre were stuffed between tiles at the slightest gap. Gradually, gradually – the “perfection” required of each tile – all 33,000 – improved and improved – until finally, concerned management – at both NASA and Rockwell Space – felt that the Shuttles could be safely flown.
The first successful launch, witnessed by those of us having devoted thousands of hours of preparation (and prayer), was a never-to-be-forgotten-moment. Then, after two more successful launches – and three years – it was time to say “Good-bye”, and return to a normal 40-50 hour work week. In 1982 NASA honored me with a Public Service award and medal.
Perhaps it was the painstaking discipline required, but USSR tried and failed – with it’s duplicative attempt at its Space Shuttle. (Worth a thought is the cost: 33,000 tiles @ $10,000 – in 1980 = 1/3 of a $Billion!).