Where I Wasn't Going Part 5

There was a gurgling churkle from the innocent-looking maze as the "borrowed" aerator pump from the FARM supplies began returning the condensate back to the boiler.

Major Steve Elbertson stood on the magnetic stat-walk of the south polar loading lock, gazing along the anchor tube to Project Hot Rod five miles away.

"There are no experts in the ability to maneuver properly in free fall," he told himself, quieting his dissatisfaction with his own self-conscious efforts at maintaining the military dignity of the United Nations Security Forces in a medium in which a man inevitably lost the stances that to him connotated that dignity.

Awkwardly, he attached the ten-pound electric device affectionately known to s.p.a.cemen as the scuttlebug, to the flat ribbon-cable that would both power and guide him to Hot Rod.

As the wheels of the scuttlebug clipped over the ribbon-cable, one above and two below, and made contact with the two electrically conductive surfaces, he saw the warning light change from green to red, indicating that the ribbon was now in use, and that no one else should use it until he had arrived at the far end.

Seeing that the safety light was now in his favor, he swung his legs over the seat--a T-bar at the bottom of the rod which swung down from the drive mechanism--grasped the rod, and pulled the starting trigger.

The accelerative force of one gee, the maximum of which the scuttlebug was capable, provided quite a jolt, but settled down very quickly to almost zero as he picked up speed and reached the maximum of one hundred twenty miles per hour.

A very undignified method of travel, he thought. Yet for all that, the scuttlebugs were light and efficient, and reduced transit time between outlying projects and the big wheel to a very reasonable time, compared to that which it would take for a man to jump the distance under his own power--and, he thought, without wasting the precious ma.s.s that rockets would have required.

The low voltage power supplied by the two flat sides of the ribbon was insufficient to have provided lethal contact, even if the person were there without the insulation of a s.p.a.cesuit around him, a very unlikely occurrence. Furthermore, the structure of the cable, with the flat, flexible insulation between its two conductive surfaces, made it practically impossible to short it out; and the f.l.a.n.g.ed wheels of the scuttlebug clipped over it in such a fas.h.i.+on that, once locked, it was thought to be impossible that they could lose their grip without being unlocked.

As Steve gained speed along the ribbon, "his" Project Hot Rod was in view before him--appearing to be a half moon which looked larger than the real moon in the background behind it; and seeming to stand in the vastness of s.p.a.ce at a distance from the far end of the long anchor tube, a narrow band of bright green glowing near its terminator line.

From the rounded half of the moon, extending sunward, four bright, narrow traceries seemed to outline a nose that ended in a pale, globular tracery at its tip, pointing to the sun.

The narrow traceries were in actuality four anchor tubes, similar to the one beside which he rode; and mounted in their tip was the directing mirror that would aim Hot Rod's beam of energy.

Project Hot Rod was actually a giant balloon eight thousand feet in diameter, one-half "silvered" with a greenish reflective surface inside that reflected only that light that could be utilized by the ruby rods at its long focal center; and that absorbed the remainder of the incident solar radiation, dumping it through to its black outside surface, and on into the vastness of s.p.a.ce. This half of the big balloon was the spherical collector mirror, facing, through the clear plastic of its other half, the solar disk.

Well inside the balloon, at the tip of the ruby barrel that was its heart, were located the boiler tubes that activated the self-centering inertial orientation servos which must remain operational at all times. If the big mirror were ever to present its blackened rear surface to the sun for more than a few minutes, the rise in temperature would totally destroy the entire project. Therefore, these servos had been designed as the ultimate in fail-safe, fool-proof control to maintain the orientation of the mirror always within one tenth of one degree of the center of Sol.

Their action was simplicity itself. The black boiler tubes were s.h.i.+elded in such a way that so long as the aim was dead center on the sun they received no energy; but let the orientation s.h.i.+ft by a fraction of a degree, and one of these blackened surfaces would begin to receive reflected energy from the mirror behind it; the liquid nitrogen within would boil, and escape under pressure through a jet in such manner as to re-orient the position to the center of the tracking alignment.

[Ill.u.s.tration]

Since the nitrogen gas escaped into the balloon, the automatic pressure regulator designed to maintain pressure within the balloon would extract an equal quant.i.ty of gas, put it back through the cooling system on the back side of the mirror, and return it as liquid to the boiler.

These jets were so carefully and precisely balanced that there was virtually no "hunting" in the system.

The balloon itself was attached to its anchor tube by a one hundred meter cable that gave free play to these orientation servos. The anchor point was the exact center of the black outside surface of the mirror-half of the balloon; and beside that anchor point was the air lock to the control center, to which Steve was now going.

From the control room, a column extended up through the axis of the balloon for thirty-five hundred feet--and most of the surface of this column was covered with the new type, high power ruby rods, thirty feet long and one-half inch in diameter, mounted in tubular trays of reflective material which took up sufficient s.p.a.ce to make each rod occupy two inches of the circ.u.mference of the tube on which it was mounted.

These ruby rods were the heart of the power system, converting the random wave fronts of noncoherent light received from the mirror into a tremendous beam of coherent infrared energy which could be bundled in such a pattern as to reach Earth's surface in a focal point adjustable from here to be something between twenty-two feet in diameter to approximately one mile in diameter.

[Ill.u.s.tration]

The banks of rods were so arranged that each of the one hundred sections comprising the three thousand feet of receptive surface at the focus of the mirror formed a concentric circle of energy beams; each circle becoming progressively smaller in diameter, so that the energy combined into one hundred concentric circles, one within the other, as it left the rods; but these circles were capable of the necessary focusing that could bring them all together into a single small point near Earth's surface.

The beam leaving the rods represented three hundred seventy-five million watts of energy, tightly packaged for delivery to Earth. But this was only a small fraction of the solar energy arriving at the big mirror.

The remainder, the loss, must be dumped by the black surface at the back; and to account for the loss in the rods themselves, to prevent their instantaneous slagging into useless globules of aluminum oxide, their excess loss energy must also be dumped.

A cooling bath of liquid nitrogen therefore circulated over each rod and brought the excess heat to the rear of the big lens, where it, too, could be dumped into the blackness of s.p.a.ce beyond.

For all its size and complexity, Hot Rod was only a trifle over six per cent efficient; but that six per cent of efficiency arriving on Earth would be highly welcome to supplement the power sources that statistics said were being rapidly depleted.

The spherical shape of the mirror itself, one of the easiest possible structures to erect in s.p.a.ce, had dictated the placement of the rods through its center since there was no single focal point for the entire mirror surface.

But it had also added a complication. From this position, the rods could have been designed to fire either straight forward or straight back.

However, due to the hollow nature of the thirty-five hundred foot laser barrel; the necessity for access to the rods from inside that barrel; and the placement of the control booth at its outside end, the firing could only be forward, straight towards the sun on which the mirror was focused.

But to be useful, the beam must be able to track an ever-moving target.

This problem had been solved by one of the largest mirror surfaces that man had ever created--flat to a quarter of a wave-length of light, and two hundred fifty feet in diameter, the beam director, from this distance looking as though it were a carelessly tossed looking-gla.s.s from milady's handbag, anch.o.r.ed one diameter forward of the big power balloon.

For all its size, this director mirror had very little ma.s.s.

Originally it had been planned to be made of gla.s.s in much the same manner as Palomar's 200-inch eye. But this plan had been rejected on the basis of the weight involved.

Instead, its structure was a rigid honeycomb of plastic; surfaced by a layer of fluorocarbon plastic which had been brought to its final polish in s.p.a.ce, and then carefully aluminized to provide a highly reflective, extremely flat surface.

This mirror was also cooled by the liquid nitrogen supplied from the back side of the big mirror. Necessarily so, since even its best reflectivity still absorbed a sufficient portion of the energy from the beam it deflected to have rapidly ruined it if it were not properly cooled.

The several tons of ruby rods in the barrel, with their clear sapphire coatings, were far more valuable than any gems of any monarch that had ever lived on Earth. Synthetic though they were, Steve Elbertson, the project's military commander, knew they had been s.h.i.+pped here at fantastic cost and were expected to pay for themselves many thousands of times over in energy delivered.

As yet, the project had had no specific target; nor had it been fully operational as of midnight yesterday.

But this "morning" for the first time the terrific energy of the laser beam would be brought to bear on the Greenland ice cap--three hundred seventy-five million watts of infrared energy adjusted to a needle-point expected to be twenty-two feet in diameter at Earth's surface, delivering one million watts per square foot, that should put a hole a good way through the several thousand feet of glacier there in its fifteen minutes of operation, possibly even exposing the bare rock beneath, and certainly releasing a mighty cloud of steam.

Focused to this needle sharpness, the rate of energy delivery was many orders of magnitude higher than that delivered by man's largest nuclear weapons only a few yards from ground zero.

Today's test was primarily scheduled as a test of control in aiming and energy concentration. Careful co-ordination of the project by ground control was vital, so that no misalignment of the beam could possibly bring it to bear on any civilized portion of Earth's surface.

For, fantastic as this Project Hot Rod might be as a source of power for Earth, Major Elbertson knew that it was also the most dangerous weapon that man had ever devised.

Therefore, the scientists were never alone in the control booth, despite the mile-long security records of each. Therefore, he and his men were in absolute control of the men who controlled the laser.

Therefore, too, Steve told himself, as the time came when there would be a question of command between himself and Captain Nails Andersen, science advisor to the U.N. and commander of s.p.a.ce Lab One, his own secret orders were that he was to take command--and the rank that would give him that command was already bestowed, ready for activation.

Nails Andersen, Steve reminded himself with amus.e.m.e.nt, had originated the laser project; had fought it through against the advice of more cautious souls; and had, through that project, attained command of the s.p.a.ce lab, and the rank that made that command possible, all in the name of civilian science.

But not command of the laser project, Steve told himself.

Not of the most dangerous military weapon ever devised--dangerous and military for all that it was a civilian project, developed on the excuse that it would power Earth, which was rapidly eating itself out of its power sources.