Quickly they lashed and anchored the crate containing the lathe and hauled it in towards the main south lock of the big wheel. * * * * * These were not the only activities in and around the wheel, or other places in space. Man already had a toehold in space, and that toehold was gradually growing into a real beachhead. Swarms of satellites in their short, fast orbits down close to Earth had been performing their tasks for many years. Astronauts had come and gone, testing, checking, probing however briefly; bravely clawing their way up the sides of the long gravitic well that separated Earth from space. The moon project that had originally been forecast for immediate accomplishment had met with delay. As yet there was no base on the moon, though men had been there, and this was bound to occur. But the lab was not here so much as a stepping stone to the moon as it was to provide information for the future manned trips out towards Mars and the asteroids; and in towards Venus and the sun. Besides research, the big wheel would provide living quarters for men building other projects; would provide a permanent central for the network of communications beams that was gradually encompassing man's world and would eventually spread to the other planets as well. Cooperating with this master communications central, other satellites, automatic so far, occupied the same orbit, leading and lagging by one hundred twenty degrees. A twenty-four hour orbit would have been more advantageous from the point of view of communications, except for the interference that would have been occasioned by the vast flood of electrons encircling Earth in the outer Van Allen belt. These electrons, trapped by Earth's magnetic field from the solar wind of charged particles escaping the sun, unfortunately occupied the twenty-four hour orbit, and, as their orbit expanded and contracted under the influence of the shifting magnetic field and solar flares, could produce tremendous havoc even in automatic equipment, so that it had been deemed economically impractical to set up the originally-postulated three satellites in stationary twenty-four orbits as communications terminals. As the next best choice, the thirty-six-hour orbit had been selected. It gave a slow rate of angular displacement, since the satellite itself moved ten degrees an hour, while Earth moved 15 deg., for a differential rate of only five degrees an hour, making fairly easy tracking for the various Earth terminals of the communications net; and making possible a leisurely view of more than ninety per cent of Earth's surface every seventy-two hours.