“The structural loads stored in the assembly by this ‘stretch’ will cause the whole stick to vibrate on release, shivering back and forth for the first few moments of flight, with a period of three or four seconds.” Dana prodded at a part of the page he had underlined heavily. “According to this rough outline, you will see that the greatest stresses on the joints of your segmented rockets are likely to occur during the ‘stretch’ and the subsequent bounce; I believe the stresses at that time might even exceed those of the period of maximum dynamic pressure during the flight.”

“The joints are designed to resist such pressures. All of this is under consideration,” Udet said, sounding a little testy.

“I’m sure it is. But I will want to see documentary evidence of tests before I could consider signing off the Critical Design Review. I have further recommendations.” He dug out more pieces of paper. “I would like to see the rubber of the segment seals replaced with a composite, temperature-resistant material. The field joints should be redesigned. All of this will reduce the possible flexing of the joints during the ‘stretch’ by many orders of magnitude. In addition, viewing ports for launch-site testing and electrical heating for the joints should be installed…”

As he went through his points, Udet listened politely, imperturbable.

A new announcement, incomprehensible to Dana, came over the sound system, and Udet turned his head to listen. When he turned back to Dana his smile was restored, creasing his papery cheeks. “We will talk further,” Udet said. “But the test fire will begin in a few minutes. If you will accompany me — you may bring your drink if you wish…”

Dana followed. Oddly, he felt as if he had acted without manners — as if it had been crass to raise all those niggling objections on a day of such visionary significance.

Udet drove Dana out to the test range in an open vehicle like a golf cart.

They stopped perhaps a mile from the booster. Udet, with an outstretched hand, helped Dana from the cart, and then to climb down a short metal ladder into an open trench. The trench was maybe four feet deep, a crude affair lined with rough-finished concrete. A technician handed Dana a set of goggles and a white hard hat.

The test booster was a cylinder of slim white, lying flat against the orange ground. The booster was strapped to the Earth by huge rectangular frames, and its nose was capped by an immense, open half sphere. As if it is a fallen god, pinned down, which might otherwise escape. The field joints between the casing segments gleamed gold in the sun, which was climbing toward noon. The big engine bell flared toward a low hill.