A Dyson shell with an inner surface partly covered by a mirror would be one incarnation of such a system (although it suffers from the same stabilization problems as a non-propulsive shell), as would be a Dyson swarm with a large statite mirror (see image above). A Dyson bubble variant is already a Shkadov thruster (provided that the arrangement of statite components is asymmetrical); adding energy extraction capability to the components seems an almost trivial extension. Astronomer Matthew E. Caplan of Illinois State University has proposed a variant of the Dyson swarm of mirrors that uses concentrated stellar energy to excite certain regions of the outer surface of the star and create beams of solar wind for collection by a multi-Bussard ramjet assembly, producing directed plasma to stabilize its orbit, and jets of oxygen-14 to push the star. Using rudimentary calculations that assume maximum efficiency, Caplan estimates the Bussard engine would use 1015 grams per second of solar material to produce a maximum acceleration of 10-9 m/s2, yielding a velocity of 200 km/s after 5 million years, and a distance of 10 parsecs over 1 million years. While theoretically the Bussard engine would work for 100 million years given the mass loss rate of the Sun, Caplan deems 10 million years to be sufficient for a stellar collision avoidance. His proposal was commissioned by the educational YouTube channel Kurzgesagt. In Olaf Stapledon's 1937 science fiction novel "Star Maker", some advanced galactic civilizations attempt to use stellar engines to propel their planetary systems across the galaxy in order to physically contact other advanced galactic civilizations. However, it turns out that the stars are life forms with a consciousness of their own, and their consciousnesses are extremely upset by this happening to them, because it violates the canon of the galactic ballet dance the stars feel they are a part of and which the stars feel is the primary focus and most sacred ritual of their lives. So, those stars whose surrounding civilizations attempt to force them to move in a different direction take revenge by committing suicide by exploding as supernovae, thus destroying their attendant worlds. This initiates the "War of Stars and Worlds", lasting millions of years, which becomes a pivotal event in the history of the galaxy. The war only ends when the galactic civilizations figure out how to telepathically communicate with the stars and arrange a truce. The novel " Manifold: Space" by Stephen Baxter has a Shkadov thruster being built around a neutron star which is destined to collide with another neutron star; the intention is to delay the collision, so that Galactic civilization will not be wiped out.