Starquake.pdf

We wanted Dragon Slayer at a 406-kilometer altitude above Egg so it would be in a synchronous orbit
about the star (with the orbital period equal to the rotation period of the star). At this distance from a
neutron star, even though the orbital motion cancels the gravity attraction at the center of the spacecraft,
the acceleration due to the tidal effects is 200 Earth gravities per meter outward in the radial direction to
the neutron star and 100 gravities per meter inward in a plane tangent to the star.
To counteract these tides the crew of St. George constructed a tidal compensator made of six
ultra-dense masses arranged in a ring around the spacecraft. As can be seen in Figure 7, the tides in the
middle of a ring of masses have a tidal pattern that is exactly opposite to that of the tides above a single
mass. By adjusting the massm and spacingr of the ring masses, we were able to compensate the tides of
the neutron star and get close enough to the star to collect good scientific data.
Later, when the cheela wanted to shrink the ring of masses, the tides from the compensator masses
became stronger than the tides from the neutron star and it was necessary to "aug-
2GmI
Figure S. Tidal Accelerations of a Two-Sphere Tidal Augmentor