The reference volume that accompanied the charts was most helpful. Stellar systems were listed by right ascension, declination, and distance; so that he merely had to find the appropriate pages to find in a single group all the systems near his line of flight.
There were twelve suns, in seven systems, lying with a light-year of his course, within the distance measured by a month's flight. Such a number was most surprising; chance alone would not insist on even one star within a cylinder of space two light-years in diameter and thirty-five long. Most of them, of course, were “dead” stars, detectable at only the closest range. Six of them had planetary systems; but the planets, without exception, possessed surface temperatures below the freezing point of mercury.
That was unfortunate. To remain alive on any of these worlds would demand that he stay in the ship, and use power, for heat and light. Even such slight radiation as that would cause meant a virtual certainty of detection by even a cursory sweep of the planet on the part of a League cruiser. He had to find a place where the ship would remain at least habitably warm without aid from its own converters. He could do without light, he thought.
The problem would not have bothered a pilot of even moderate experience, of course. The ship could easily be set in a circular orbit of any desired radius about one of the stars. Unfortunately, there is a definite relation between the mass of a star, the radius of the desired orbit, and the amount of initial tangential velocity required; and this simple relation was unknown to La Roque. Trial and error would be very unsatisfactory; the error might be unnoticeably small to start with, and become large enough to require correction when searchers were around. A worried frown began to add creases above La Roque's black brows as the little flyer raced on.
The spot of light in the front vision plate grew paler as Sol, who provided most of its radiance, faded astern. Within a day, he was merely a bright star; in a week, dozens of others outshone him whenever La Roque cut the drive fields. Space, the runaway began to realize, was a terrifying lonely environment. Earth was beginning, in his memory, to assume a less forbidding aspect.
Two days out, he passed the first of the seven systems. It was not visible, at half a light-year, even when the fields were off; the chart reference described it as a binary, both stars cool enough to have clouds of solid and liquid particles in their atmospheres, and neither emitting any visible radiation to speak of. The relative orbit was of almost cometary eccentricity, with a period of about seventy years. The suns had passed periastron about a dozen years before, without anyone's being greatly concerned.
It was a dry collection of data, but it jogged La Roque's mind into recalling something. He had been picturing the result of an error in establishing an orbit, as being a spiral drop into the star he had chosen. Now he recalled that he would merely find himself in a slightly eccentric, rather than a circular, orbit; and if the eccentricity were not great enough to bring his periastron point actually within the star's atmosphere, it would be perfectly stable.
The idea attracted him for a moment; even he could set up a passable concealment orbit. The possibility of being alternately too warm and too cold was unpleasant, but not forbidding. The system he was passing would not do, of course; he took it for granted that the perturbations produced by the companion star would nullify his attempts. However, four single suns were among those he had looked up along his course, and were within easy reach.
It remained to choose one of the four. Any reasonable and normal person would have without hesitation laid a course for the nearest; La Roque, under the elemental motivation that sent an incognito Hitler to Borneo rather than Switzerland, chose the farthest. Perhaps his gambling spirit had something to do with the choice; for there was actually some doubt that he would reach the star before a League cruiser would come nosing along his wake into detection range.
From where he was, the runaway could not lay a direct course for his chosen hideout. His knowledge of solid geometry and trigonometry was so small that all he could do was to continue on his present course until the proper heliocentric distance was attained, then stop, put Sol exactly on his beam, hold it there while he turned in the proper direction, and again run in second-order flight for a certain length of time — dead reckoning pure and very simple. By thus reducing his goal position to a known plane — or near plane; actually the surface of a sphere centered on Sol — he could get the course of his second leg by simply measuring, on a plane chart, the angle whose vertex was the point in the sky toward which he had been driving, and whose sides were determined, respectively, by some beacon star such as Rigel or Deneb, and the star of his destination. He dragged out a heliocentric chart and protractor, and set to work.
Time crawled on. The nearer stars, on the trail photographs, drifted sluggishly toward Sol. La Roque found a photometer, and managed to obtain with its aid a check on his distance from the Solar System. He spent much of his time sleeping. There was nothing to read except the charts, astrographical and planetographical references, and the numbers on the currency leaves whose gathering had necessitated his departure from Earth. The latter kept up his morale for a while.
Second-order pilotage is not difficult; it depends chiefly on proper aiming of the ship before cutting in of the converters. There is practically no tendency to drift from the original heading; in fact, it is impossible to turn without cutting the fields and re-aligning the vessel's axis. Actually, the ship will follow the arc of a circle whose radius depends to some extent on the power of the generators, but in any case is so enormous that a “local” interstellar flight may be considered rectilinear. La Roque's intended flight path was so short that his ignorance of short-order field technology made no difference. An experienced navigator, planning a flight across the galaxy, or to one of the exterior systems, would have to forecast and allow for the “drift” caused by generators of any given make and power.
One by one, the star systems La Roque had rejected dropped behind. Each time he fought the temptation to turn aside and seek refuge. Days turned into weeks, three of them, from the time he had chosen his destination. By the most generous estimate, his margin of clearance from the law was growing narrow, when he cut the fields at — according to his reckoning — twenty-eight point seven seven four seven light-years from the Solar System.
He snapped on plate after plate, looking around in every direction. A fifth-magnitude star on the cross wires of the rear plate was, of course, Sol. He looked for Deneb, but Cygnus was too badly distorted by a parallactic variation of nine parsecs to permit him to identify its alpha star with certainty. Orion was recognizable, since he had been moving more or less directly away from it and all its principal stars were extremely distant; so he decided to use Rigel to control his direction.
He zeroed the cross wires of one of the side plates and, using the gyros, swung the ship until Sol was centered on that plate. Rigel was, conveniently, visible on the same plate; so he snapped a switch which projected a protractor onto it, and swung the ship again until Rigel was on the proper — according to his measures — radius. Using the plate's highest power, he placed the two stars to four decimals of accuracy, released the gyro clutches, and cut in the second-order fields before friction at the gyro bearings could throw off his heading.
His arithmetic said he had eight hours and thirty minutes of flight to his destination. Experience would have told him that his chances of stopping within detection range of his goal were less than one in a hundred thousand; as it was, the chief worry that actually disturbed him was whether or not there was risk of collision. Not too surprising! In dead reckoning, the novice navigator makes a tiny point and says, “Here we are.” The junior makes a small circle and says the same. The experienced navigator lays the palm of his hand on the chart and says, “We ought to he here.” And La Roque's was the deadest of dead reckoning.