Zamok Sabyel'

Poul Anderson, Harvest Of Stars, 60.

In the Centaurian System, not only have the Lunarians colonized Perun and other asteroids but also Phyle Ithar has constructed a hundred-kilometers-long, orbiting, spinning zamok (castle) with:

a hub;
radiating spokes joined by cables and tubeways;
a rim with lights and ports;
missiles, ray projectors and robotic vessels as defense against meteors;
four solar collectors like wings "...scything across Milky Way and stars..." (p. 500)

Demetrian Captain Erling Davis, having brought his crewed ship from Odysseus, is welcomed by Lady Commander Rusaleth of Ithar. Guthrie had helped her phyle against Arcen and Yanir who had tried to storm Zamok Sabyel'. Davis' naval service had been with the irregulars, McCannon's Kids. Their weapons included superlasers, explosives, rocks and spaceship jets and they had exploited the lower acceleration tolerance of their opponents.

Demeter has:

a republican Folkhouse;
the immortal Guthrie;
the Life Mother;
simple nature dwellers;
hectic town dwellers.

Demetrians and Lunarians must prepare for the time when Phaeton not only destroys Demeter but also fills the system with dangerous shards. Demetrians have a larger population with a higher acceleration tolerance and have extended the limit of suspended animation to about a century. A Lunarian physicist theorizes that transference of momentum between spaceship and cosmos might generate near-light speeds. Erling refers to the Casimir effect, virtual particles and work from the vacuum (as with the zero-zero drive in Starfarers?) 60 also presents detailed, colorful information about life inside Zamok Sabyel'. We do not know how many generations after Kyra Davis Erling has been born. Like most Demetrians, he is also descended from Guthrie.

In its PART THREE, Harvest Of Stars systematically transcends itself as sf should.