Tides of Light by Gregory Benford

scratch out an existence here.
    “Why’s it happening now?” Shibo mused.
    “Just as we arrive?” Killeen read her thoughts. “Could be this is what the Mantis wanted us for.”
    “Hope not,” Shibo said with a sardonic twist of her lips.
    “We had plenty bad luck already,” Cermo said.
    Shibo studied the board. “I’m getting something else, too.”
    “Where?”
    “Coming up from near the south pole. Fast signals.”
    “What kind?”
    “Like a ship.”
    Killeen peered at the screen. The glorious squashed circle had cut slightly farther into the planet. It was still aligned
     with its flattened face parallel to the rotation. He estimated the inner edge would not reach the planet’s axis for several
     more hours at least. As it intruded farther, the hoop had to cut through more and more rock, which probably slowed its progress.
    Shibo shifted the view, searching the southern polar region. A white dab of light was growing swiftly, coming toward them.
     It was a dim fleck compared with the brilliant cosmic string.
    “Coming toward us,” she said.
    “Maybe cargo headed for the station, if they’re still carrying out business as usual.” He cut himself short; it did no good
     to speculate out loud. A crew liked a stony certainty in a Cap’n; he remembered how Cap’n Fanny had let the young lieutenants
     babble on with their ideas, never voicing her own and never committing herself to any of their speculations.
    He turned to Cermo. “Sound general quarters. Take up positions to seize this craft wherever it comes in.”
    Cermo saluted smartly and was gone. He could just as easily have hailed the squads of the Family from the control vault, but
     preferred to go on foot. Killeen smiled at the man’s relishing this chance to take action; he shared it. Pirating a mech transport
     was pure blithe amusement compared with impotently watching the hoop cut into the heart of their world.
    The three midshipcrew left hurriedly, each taking a last glance at the screen where two mysteries of vastly different order
     hung, luminous and threatening.

TWELVE
    Killeen glided silently around the sleek craft, admiring its elegant curves and economy of purpose. Its hull was a crisp ceramo-steel
     that blended seamlessly into bulging flank engines. The capture had been simple, flawless.
    The squad that had seized it hovered near both large airlocks in the ship’s side. They had waited here in the station’s bay,
     and done nothing more than prevent six small robo mechs from hooking up power leads and command cables to the ship’s external
     sockets. Without these, the craft floated inertly in the loading bay.
    It was clearly a cargo drone. Killeen was relieved and a little disappointed. They faced no threat from this ship, but they
     would learn little from it, as well.
    It is of ancient design. I recall the mechs using such craft when they transported materials to Snowglade. I believe I could
     summon up memories of how to operatethem, including the difficulties of atmospheric reentry. They were admirably simple. People of times before mine often hijacked
     them for humanity’s purposes.
    Arthur’s pedantic, precise voice continued as Killeen inspected the loading bay. Arthur pointed out standard mechtech. The
     Aspect was of more use here, where older, high-vacuum tech seemed to have changed little in the uncounted centuries since
     humanity had been driven from space altogether. On Snowglade the mechs had adapted faster than humans could follow, making
     the old Aspects nearly useless. Arthur’s growing certainty about their surroundings in this station began to stir optimism
     in Killeen.
    Flitters! See there?
    A squad member, exploring nearby in the station, had fumbled her way through a lock. A large panel drew aside, revealing a
     storehouse of sleek ships similar to the cargo drone they had just seized.
    These are quick little craft that can reach the surface with ease. I remember them well. We termed them Flitters