their own gravity-bound planet until well afterthe spin supplied pseudo-gravity to the ship; but the schedule of theshuttles' loads had proved such as to make possible the trip eitherfar in the future, or to put him aboard on this trip, with spin only afew hours away.

  The cages, with their loads of guinea pigs, rabbits, hamsters andother live animals to be used in the sacrificial rites of biochemicalresearch were, to put it mildly, a mess. Provision had been made forfeeding and watering the animals under free-fall conditions, butkeeping them sanitary was proving a near-impossible task; and thoughthe cages were sealed to confine the inevitable upset away from theremainder of the lab, it was good to hear that the problem was nearlyover as the news of the imminent countdown came over the loud-speaker.

  Meantime, Dr. Claude Lavalle was having his difficulties, and hewished fervently that his assistants could have been sent up on theshuttle with him.

  * * * * *

  In rim-sector A-10, the FARM (Fluid Agricultural Recirculating Methodcontrol lab, according to the U.N. acronym), Dr. Millie Williams, hersatiny brown skin contrasting to her white T-shirt and shorts, wasalso having her troubles.

  The trays of plants, in their beds of sponge plastic and hydroponicmaterials, were all sealed against free-fall conditions, but should beoriented properly for the pseudo-gravity as the great wheel was givenits rotational spin.

  The vats of plankton and algae concentrates were not so important asto orientation, but should be fed into their rim-river homes as soonas possible, although this could not be done until the rim spin waswell under control.

  The trays, the plants, the plankton, the algae--even a largeproportion of the equipment in the lab, were all new, experimentalprojects, designed to check various features of the food and aircycles that would later be necessary if men were to send their shipssoaring out through the system.

  The primary purpose of Lab One was a check of the various survivalsystems and space ecology programs necessary to equip the futureexplorations under actual space conditions. Her job on the FARM wouldbe very important to the future feeding and air restoration ofspacemen; but more important, the efficient utilization of the wheelitself, since success in shipboard purification of air and productionof food would free the shuttle to bring up other types of mass.

  At present, the ship's personnel were existing almost entirely ontanked air, but within two weeks one of the three air-restorationprojects on the satellite--either hers, in which hydroponic plants andalgae were the basic purifiers; or projects in the chem and physicslabs--would have to be already functioning in the job, or extrashuttles would have to be devoted to air transportation until theywere ready.

  The provision of good fresh vegetables and fresh, springlike air wouldalmost certainly be up to her department. The other two labs, Dr.Carmencita Schorlemmer in chemistry, and Dr. Chi Tung in physics, wereboth working on the air-restoration problem by differentmeans--electro-chemistry in the one case; gas dialysis membranes inthe other.

  The work of the physics labs was operating on the differential abilityof various gas molecules to "leak" through plastic membranes underpressure, causing separation of the various molecular constituents ofthe atmosphere; shunting carbon dioxide off in one direction, andreturning oxygen and the inert nitrogen and other gases back to thesurrounding atmosphere.

  This latter method had proved highly satisfactory back on Earth, whereit was separating out fissionable materials in large quantities andhigh purities from closely similar isotopes; and would now be testedfor efficiency versus weight in some of the new problems beingencountered in space.

  A fourth method, direct chemical absorption by soda lime, had beendiscarded early in the program, although it was still used inspacesuit air cleaners, and for the duration of the canned air programunder which they were now operating.

  The lab was like that--no problem has a single solution. And it wasthe lab's job to evaluate as many solutions as possible so that thebest, under different conditions, might be proved and ready for use inlater programs.

  * * * * *

  Paul Chernov, ordinary spaceman--which meant that he had only a littlemore specialized training than the average college graduate--wasworking in the dump, surrounded by much of the equipment that remainedto be placed aboard Space Lab One, and trying to identify theparticular object he sought.

  Looking down almost directly over the eastern bulge of the Africancoast, he sighted what was probably the ECM lathe he was after, andkicked towards it, simultaneously pulling his pistol-gripped Rate ofApproach Indicator from the socket in his suit.

  The RAI gun, he sometimes felt, was the real reason he'd become aspaceman in these tame days. Even if he couldn't be a space pirate, itgave him the feel.

  Humming to himself, he aimed the search beam from the tinygallium-arsenide laser crystal that was the heart of the gun at thebulky object, and read off the dial at the back of the "barrel" thetwo meter/second approach velocity and the twenty-eight meterdistance.

  He could as easily have set the RAI gun to read his velocity anddistance in centimeters or kilometers, and it would have read as wellhis rate of retreat, if that had been the factor.

  Paul's RAI gun might be, to others, a highly refined, vastly superiorgreat-grandson of the older radar that had required much more in theway of equipment than the tiny bulk of this device, but to him, alonein his spacesuit, the galaxy spread around him, it was the weapon withwhich he had conquered the stars.

  In the distance, off beyond the wheel in a trailing orbit, the hugespherical shape of Project Hot Rod glowed its characteristicgreen--another application of the laser principle, but this onemacroscopic in comparison to the tiny laser rate-of-approach gun.

  Happily, Paul burst into song.

  _"There's a sky-trail leading from here to there And another yonder showing; But I've a yen for gravity-- This is where I wasn't going!"_

  From the other side of the dump, Tombu's voice bellowed into his earsover the intercom. "If you're going to audition for the stars, cutdown the volume!"

  Paul grinned and reached for the volume control.

  "O.K., M'Numba, 's m'numba!--I'm a space-yodler from way out. Heave aline over this way and let's get this ECM lathe aboard."

  Tombu's "last name" M'Numba had delighted Paul from the moment he'dheard the story of its origin. By the customs of his own country,Tombu had only a single name. However, when he had first enrolled as astudent in England there had been a lack of comprehension between himand the rather flustered registrar and, when he had muttered somethingabout "my number," the registrar had misunderstood and put him down asM'Numba. Tombu had let it stand.

  Paul Chernov, fine-boned, blond, with an ancestral background of thePolish aristocracy, and his side-kick, Tombu, black, muscular giantfrom the Congo, were one of the strangest combinations of thisinternational space lab crew. Yet it was perhaps even stranger thatthe delicate-looking blond youth was a top machinist, a trade that hehad plied throughout his student days in order to economically supportan insatiable thirst for knowledge. A trade that had led him to thisnewest center of man's search for knowledge.

  But perhaps the combination was not so strange, for Tombu, also, wasof the aristocracy--an aristocracy that could perhaps be measured interms of years extending far behind the comparable times for anyEuropean aristocracy.

  Tombu was Swahili, a minor king of a minor country which had neverbeen recognized by the white man when he invaded Africa and set up hisvast protectorates that took no account of the peoples and theirtribal traditions; protectorates that lumped together many hundreds ofindividual nations and tribes into something the white man looking atmaps could label "Congo."

  Tombu himself, educated in the white man's schools to the white man'sways, and probing ever deeper into the white man's knowledge, was onlyvaguely aware of his ancestral origin. He counted his kingdom innegative terms, terms that were no longer applicable in a modernworld. Where national bound
aries everywhere were melting further andfurther into disuse, it would seem to his mind foolish to lay claim toa kingship that had been nonexistent for more than one hundred yearsover a people that had been scattered to the four winds and groundtogether with other peoples in the Belgian Congo protectorate.

  Odd the combination might be; but together the two machinists workedwell, with a mutual respect for each other's abilities and a mutualunderstanding that is rare to find among members of different races.

  Quickly they lashed and anchored the crate containing the lathe andhauled it in towards the main south lock of the big wheel.

  * * * * *

  These were not the only activities in and around the wheel, or otherplaces in space. Man already had a toehold in space, and that toeholdwas gradually growing into a real beachhead. Swarms of satellites intheir short, fast orbits down close to Earth had
Leigh Richmond and Walt Richmond's Novels