On Basilisk Station

Tellerman was one of the 'Roaring Deeps,' the most powerful grav waves ever charted. More than that, it headed almost directly towards the People's Republic of Haven. If there truly was a Peep battle squadron out here, the Tellerman would take Sirius to meet it at two and a half or three thousand times the speed of light.

Back in the early days of hyper flight, spacers would have avoided something like the Tellerman like death itself, for death was precisely what it would have meant for any starship that encountered it.

The original hyper drive had been a mankiller, yet it had taken people a while to realize precisely why that was. Some of the dangers had been easy enough to recognize and avoid, but others had been far more difficult to identify and account for—mainly because people who encountered them never came back to describe their experience.

It had been discovered early on that translating into or out of the alpha band, the lowest of the hyper bands, at a velocity greater than thirty percent that of light was suicide, yet people had continued to kill themselves for centuries in efforts to translate at speeds higher than that. Not because they were suicidal, but because such a low velocity had severely limited the usefulness of hyper travel.

The translation into or out of any given band of hyper space was a complex energy transfer that cost the translating vessel most of its original velocity—as much as ninety-two percent of it, in the case of the alpha band. The energy loss dropped slightly with each 'higher' hyper band, but its presence remained a constant, and for over five standard centuries, all hyper ships had relied on reaction drives.

There were limits to the amount of reaction mass a ship could carry, and hydrogen catcher fields didn't work in the extreme conditions of hyper space. That had effectively limited ships to the very lowest (and 'slowest') hyper bands, since no one could carry enough reaction mass to recover velocity after multiple translations. It also explained why more stubborn inventors had persisted in their costly efforts to translate at higher velocities in order to maintain as much starting velocity in hyper space as possible. It had taken over two hundred years for the .3 c limitation to be fully accepted, and even today, some hyper physicists continued to search for a way around it.

Even after one had resolved the problems of safe translation speeds, however, there was the question of navigation. Hyper space wasn't like normal space. The laws of relativistic physics applied at any given point in hyper, but as a hypothetical observer looked outward, his instruments showed a rapidly increasing distortion. Maximum observation range was barely twenty light-minutes; beyond that, the gravity-warped chaos of hyper and its highly charged particles and extreme background radiation made instruments utterly unreliable. Which, of course, meant that astrogation fixes were impossible, and a ship that couldn't see where it was going seldom came home again.

The answer to that one had been the hyper log, the interstellar equivalent of the ancient inertial guidance systems developed on Old Earth long before the Diaspora. Early-generation hyper logs hadn't been all that accurate, but they'd at least given astrogators a rough notion of where they were. That had been far better than anything that had come before, yet even with the hyper log, so many ships never returned that only survey vessels used hyper space. Survey crews had been small, fantastically well-paid, and probably just a bit crazy, but they'd kept hyper travel in use until, eventually, one or two of them encountered what had killed so many other starships and survived to tell about it.

Hyper space itself was best considered as a compressed dimension which corresponded on a point-by-point basis to normal space but placed those points in much closer congruity and so 'shortened' the distance between them. In fact, there were multiple 'bands,' or associated but discrete dimensions, of hyper space. The 'higher' the band, the shorter the distance between points in normal space, the greater the apparent velocity of ships traveling through it ... and the higher the cumulative energy cost to enter it.

That much had been understood by the earliest theorists. What they hadn't quite grasped was that hyper space, formed by the combined gravitational distortion of an entire universe's mass, was itself crossed and crisscrossed by permanent waves or currents of focused gravity. They were widely separated, of course, but they also might be dozens of light-years wide and deep, and they were deadly to any ship which collided with one. The gravitational shear they exerted on a starship's hull would rip the hapless vessel apart long before any evasive action could even be contemplated, unless the ship happened to impact at precisely the right angle on exactly the right vector, and its bridge crew had both the reflexes and the reaction mass to wrench clear in time.

As time passed, the survey ships that survived had mapped out reasonably safe routes through the more heavily traveled regions of hyper space. They couldn't be entirely relied upon, for the grav waves shifted position from time to time, and sticking to the safe lanes between waves often required vector changes reaction-drive ships simply could not make. That meant hyper voyages had tended to be both indirect and lengthy, but the survival rate had gone up. And as it climbed, and as physicists went out to probe the grav waves they now knew existed with ever more sophisticated instruments, observational data increased and ever more refined theories of gravity were proposed.

It had taken just over five hundred years, but finally, in 1246 P.D., the scientists had learned enough for the planet Beowulf to perfect the impeller drive, which used what were for all intents and purposes 'tame' grav waves in normal space. Yet useful as the impeller was in normal space, it was extraordinarily dangerous in hyper. If it encountered one of the enormously more powerful naturally occurring grav waves, it could vaporize an entire starship, much as Honor herself had blown the Havenite courier boat's impeller nodes with Fearless's impeller wedge.

More than thirty years had passed before Dr. Adrienne Warshawski of Old Earth found a way around that danger. It was Warshawski who finally perfected a gravity detector which could give as much as five light-seconds' warning before a grav wave was encountered. That had been a priceless boon, permitting impeller drive to be used with far greater safety between grav waves, and even today all grav detectors were called 'Warshawskis' in her honor, yet she hadn't stopped there. In the course of her research, she had penetrated far deeper into the entire grav wave phenomenon than anyone before her, and she had suddenly realized that there was a way to use the grav wave itself. An impeller drive modified so that it projected not an inclined stress band above and below a ship but two slightly curved plates at right angles to its hull could use those plates as giant, immaterial 'sails' to trap the focused radiation hurtling along a grav wave. More than that, the interface between a Warshawski sail and a grav wave produced an eddy of preposterously high energy levels which could be siphoned off to power a starship. Once a ship had 'set sail' down a grav wave, it could actually shut down its onboard power plants entirely.

And so the grav wave, once the promise of near certain death, had become the secret to faster, cheaper, and safer hyper voyages. Captains who had avoided them like the plague now actively sought them out, cruising between them on impeller drive where necessary, and the network of surveyed grav waves had grown apace.

There had still been a few problems. The most bothersome was that grav waves were layers of focused gravity, subject to areas of reverse flow and unpredictable bouts of 'turbulence' along the interfaces of opposed flows or where one wave impinged upon another. Such turbulence could destroy a ship, but it was almost more frustrating that no one could take full advantage of the potential of the Warshawski sail (or, for that matter, the impeller drive) because no human could survive the accelerations which were theoretically possible.

Improved Warshawskis had tended to offset the first difficulty by extending their detection range and warning ships of turbulence. With enough warning time, a ship could usually trim its sails to ride through turbulence by adjusting their density and 'grab factor,' though failure to trim in time remained deadly, which was why Sirius's claim of tuner flutter had been so serious. A captain still had to see it coming, but the latest generation detectors could detect a grav wave at as much as eight light-minutes and spot turbulence within a wave at up to half that range. The problem of acceleration tolerance, on the other hand, had remained insoluble for over a standard century, until Dr. Shigematsu Radhakrishnan, probably the greatest hyper physicist after Warshawski herself, devised the inertial compensator.

Radhakrishnan had also been the first to hypothesize the existence of wormhole junctions, but the compensator had been his greatest gift to mankind's diaspora. The compensator turned the grav wave (natural or artificial) associated with a vessel into a sump into which it could dump its inertia. Within the safety limits of its compensator, any accelerating or decelerating starship was in a condition of internal free-fall unless it generated its own gravity, but the compensator's efficiency depended on two factors: the area enclosed in its field and the strength of the grav wave serving as its sump. Thus a smaller ship, with a smaller compensator field area, could