As the details of its new orbit became more and more clearly defined, it was hard to see how Rama could possibly escape disaster. Only a handful of comets had ever passed as close to the sun; at perihelion, it would be less than half a million kilometres above that inferno of fusing hydrogen. No solid material could withstand the temperature of such an approach; the tough alloy that comprised Rama's hull would start to melt at ten times that distance.
Endeavour had now passed its own perihelion, to everyone's relief, and was slowly increasing its distance from the sun. Rama was far ahead on its closer, swifter orbit, and already appeared well inside the outermost fringes of the corona. The ship would have a grandstand view of the drama's final stage.
Then, five million kilometres from the sun, and still accelerating, Rama started to spin its cocoon. Until now,, it had been visible under the maximum power of Endeavour's telescopes as a tiny bright bar; suddenly it began to scintillate, like a star seen through horizon mists. It almost seemed as if it was disintegrating; When he saw the image breaking up, Norton felt a poignant sense of grief at the loss of so much wonder. Then he realized that Rama was still there, but that it was surrounded by a
shimmering haze.
And then it was gone. In its place was a brilliant, star like object, showing no visible disc - as if Rama had suddenly contracted into a tiny ball. It was some time before they realized what had happened. Rama had indeed disappeared: it was now surrounded by a perfectly reflecting sphere, about a hundred kilometres in diameter. All that they could now see was the reflection of the sun itself, on the curved portion that was closest to them. Behind this protective bubble, Rama was presumably safe from the solar inferno.
As the hours passed, the bubble changed its shape. The image of the sun became elongated, distorted. The sphere was turning into an ellipsoid, its long axis pointed in the direction of Rama's flight. It was then that the first anomalous reports started coming in from the robot observatories, which, for almost two hundred years, had been keeping a permanent watch on the sun.
Something was happening to the solar magnetic field, in the region around Rama. The million-kilometre-long lines of force that threaded the corona, and drove its wisps of fiercely ionized gas at speeds which sometimes defied even the crushing gravity of the sun, were shaping themselves around that glittering ellipsoid. Nothing was yet visible to the eye, but the orbiting instruments reported every change in magnetic flux and ultra-violet radiation.
And presently, even the eye could see the changes in the corona. A faintly-glowing tube or tunnel, a hundred thousand kilometres long, had appeared high in the outer atmosphere of the sun. It was slightly curved, bending along the orbit which Rama was tracing, and Rama itself - or the protective cocoon around it - was visible as a glittering head racing faster and faster down that ghostly tube through the corona.
For it was still gaining speed; now it was moving at more than two thousand kilometres a second, and there was no question of it ever remaining a captive of the sun. Now, at last, the Raman strategy was obvious; they had come so close to the sun merely to tap its energy at the source, and to speed themselves even faster on the way to their ultimate unknown goal ...