There was a switch hidden behind a plate at the base of one of the four stabilizing fins of the booster. This closed an electrical circuit running through a conducting core concealed within the lay of the parachute cable. When current flowed, it set in motion a reefing motor located in a watertight casing at the open end of the parachute. The motor reeled in a thin steel cable which closed the bight of the parachute down to a few meters as it hung deep under water at the end of its cable.
Now the steamer's engines went slow ahead and the great parachute began to open as far as the draw-line tightened by the reefing motor would permit, but still creating much drag behind the slowly moving vessels. As the speed of the steamer increased, the parachute on the end of its cable, now secured to bits at the stern of the ship, began to approach the surface. It streamed out behind the ship at an ever flatter angle, until some fifty meters astern, the first visible meshes of the 'chute appeared above the boiling wake.
Soon, almost the whole pocket of the great mass of metal ribbons was whirling and flashing near the surface like a school of flying fish. The long sailcloth roll had been pushed up beneath the parachute by the dynamics of the water and was raising the whole thing above the surface, much as a man on an aquaplane is supported by it.
At last, the parachute lay with its whole length clear of the water and was kept narrow within the width of its supporting sail by the drawstring.
Now a man on deck pushed a button and a solenoid in each of the two disk-like affairs at the far end of the sail pushed off two can-shaped covers. This revealed on each disc a little water wheel with spoon-shaped paddles. Promptly beginning to revolve in the wake of the advancing steamer, these wheels began to roll up the sail and the parachute within it around their common axle. It seemed that the towed sail was growing shorter as the roll it made at its after end grew thicker and thicker.
Some 40 meters astern of the steamer, this rolling-up process stopped due to the weight of the axle and its burden being too great to be supported above water by the now shortened sail. At this point an electric motor began to rotate the huge drum upon which the towing sail had been stowed. The sail was wound back onto it until the great mass, nearly 12 feet in diameter, between whose folds lay the dual layers of sail and parachute, was clear of the water. Just before this emerged, there appeared an enormous swivel weighing some two tons. This swivel, joining the parachute suspension line to the shroud lines of the great canopy, was to prevent any fouling of the latter if the body of the booster should begin to rotate while in descent.
The carpet-like roll of parachute and towing sail was not hauled inboard, but secured to the after section of the hull, well above the waterline. Then, as the steamer's screw began to turn in earnest and her course was set for Christmas Island, the radio flashed the welcome news of another successful booster salvage to the Ferry Command.
The spacious inspection and repair building for recovered boosters stood close by the bulkhead of the inner basin of Christmas Island. As the Steamer came alongside, the ship's crane deposited the booster gently on a wide trailer which was then promptly hauled into the building.
Here the reconditioning procedure began immediately, starting with the drying process by blasts of hot air. These removed any remaining traces of water from the booster's ducting within a few hours. Still on its trailer, the booster next went into one of the test chambers, where it was thoroughly inspected for dents, damage and sprung rivets.
The electricians connected the plugs on either end to their multipoled testing circuits which terminated in a profusion of test panels upon which glittered masses of switches, gauges, meters and test lamps. This revealed any defect in the magnetic valves, switching relays, servomotors and the rest of the complicated equipment which rendered the launching of a Sirius well-nigh automatic. Other mechanics connected compressed air mains to the tubing of the propulsion unit, verifying its leakproofness and the operation of its multiplicity of valves.
Any defects revealed during these inspections were immediately made good by specially trained crews carrying appropriate replacement parts.
Usually there were a few minor elements whose operation might be considered unsatisfactory, such as a sticky relay or a recalcitrant valve. All such commonly required parts were kept in stock in the building itself and could be obtained without delay. But occasionally there was major damage to be repaired. In such cases, which might vary from a crack in a seam weld on the rocket motor to a defective turbopump, the entire hull section of the booster might be hoisted by the overhead crane, as an undershirt is stripped from a patient in a hospital. The workmen would swarm around the inner structure like bees and remove the defective unit, installing a new motor or turbopump in laborious hours or even days of effort.
One of the regular operations in preparing a salvaged booster for a new flight was the replacement of the exhausted deceleration powder rockets. Each of these ten rockets, as it checked the descent of the great booster a few meters above the ocean, developed a full 250 tons of thrust. It was a little more than \Vz meters in diameter and was about two meters long. The powder charge weighed 2.5 tons and was loaded in steel drums weighing almost 1.5 tons empty. When the powder was ignited, it burned for two seconds, expelling its gas in a violent jet of flame at a pressure of 200 atmospheres to produce the upward thrust which slowed the downward motion of the plunging booster.
When this work was completed and the test section had certified the booster as ready for service, a tractor hooked on to the trailer and dragged it over a pit where the parachute was installed. This pit was just outside the building. The parachutes themselves were taken directly from the salvage steamer to a separate shop where they were removed from the rolled towing sails, thoroughly inspected, and finally given a new coating of corrosionproofing.
Then they were skillfully loaded into special metal containers and sent to the installation pit. Here a hydraulic ram pushed the container upwards into the parachute housing of the booster. It was locked in, and the suspension cable was attached.
Two assembly sheds were located some eight miles away along the ring of the atoll, on which a wide concrete road had been constructed. The trailer was towed to the sheds not far from the launching site. Each shed was an enormous, tower-like structure some 70 meters high and each could contain four complete Siriuses at a time. Within each shed there was a mighty overhead traveling crane which lifted the complete booster slightly from its trailer as it came in, while the trailer was removed. The heavy metal annulus from which the launch would be made was on rails and was run under the booster which the crane gently lowered onto it.
It was not time to mount the second, or "baby," booster, as the Space Forces called it. Looking somewhat like an egg truncated at one end and in the middle, it was brought into the shed and made ready. It was 20 meters in diameter at one end, thus matching that of the "big" booster. At the upper end it tapered roundingly to 10 meters, above which section the third stage would find its place. The whole baby booster was about 14 meters high.
Now the traveling crane lifted the baby and set it in place atop the stumpy taper of the "big" booster's upper level. The taper also served as jet deflector for the baby when the latter's rocket motor began to spew flames after the propellants of the larger and lower rocket stage were exhausted. Around the taper there were four vertical guide rails into which the baby was now carefully fitted. A bare meter above the tip of the jet deflector cone, the lower part of the small booster came to a stop. Four mechanical couplings which provided the rigid connection between the stages clicked shut. They would part electromagnetically only in flight, when the big booster was to drop off. As the couplings snapped shut, the multiple-pole electric jacks and plugs also connected firmly.