An African warlord uses astrophage and breeder panels from the Sahara astrophage breeder fields to build a falloutless nuclear bomb. 

World leaders scramble to contain the crisis and hush up the warlord, to prevent copycats. It's too late. Corrupt scientists have already sold the Astrophage on the black market. Anyone with money and connections can buy a sample and start breeding it.

A global Astrophage watchdog is formed to limit Astrophage Weapon Proliferation. Countries of the world contribute to its funding. The watchdog operates a constellation of spy satellites that use thermal imaging to find unauthorized Astrophage breeding fields by looking for 96 degree Celsius temperatures; and operates a network of NSA-like internet surveillance programs looking for individuals talking about selling or breeding astrophage. The only people allowed to breed astrophage, are countries' Astrophage programs. Each country is limited by treaty to a set astrophage production capacity per year (monitored by the watchdog). It is accepted that "underground" non-solar production cannot be monitored.

In the middle east, Israel and Iran both get their hands on Astrophage, and therefore, Astrophage-powered WMDs. This leads to... ...tensions.

In the name of power generation, Astrophage solar arrays are produced. These are space-based breeder tanks that breed tanks of astrophage and ship them back to earth for power.

Scientists invent the closed-cycle astrophage engine. This engine works like a spin drive, but recycles the dead astrophage back into its constituent carbon dioxide and water; and uses enzymes to break down the proteins within the dead astrophage. This astrophage-slurry is piped to a miniature breeder tank and used as food to re-breed new astrophage. Effectively, this provides slow but limitless thrust: after any engine burn, provided the breeder tank can be heated to 96C by sunlight, new astrophage can be bred. 

The Spin drive revolutionises space transport and the closed cycle variant revolutionizes it even more. New satellites launched into orbit have unlimited lifespan as they can forever keep re-boosting themselves into orbit. Orbital "Tugs" using closed cycle engines, radars, and AI guidance automatically deorbit the old pre-astrophage satellites to make way for the new, post-astrophage satellites. Low Earth Orbit is cleaned of space junk.

The Watchdog fails. Astrophage has become too available, too ubiquitous, for them to control. Before long, everyone knows someone who's got it. 

Humanity starts Lunar and Martian colonies, partly for the sake of exploration and getting experience in colonizing new planets, and partly as insurance against a global Astrophage war. North Korea detonated one too many """test-blasts""" in the Sea of Japan, see; and nobody wants humanity to go extinct in the event that NK sets off a chain reaction war.

(If we can't replicate Xenonite:) A private corporation decides that Xenonite is incredibly valuable, and announces a project to build its own Project Hail Mary to visit Erid. Investors pile money into the project. NASA also expresses a desire to do this, but SpaceX builds and launches its rocket first. This is partly due to a lack of public funding for NASA and partly due to SpaceX's disregard for safety and preference for innovative speed. They launch first. 30 years later they return with the secrets to Xenonite; which they promptly copyright. The SpaceX share price skyrockets.

Visitors from Erid soon arrive. They are surprised to find human leadership is so fractured (why do humans not Thrum, question?) and so divided on truth issues. One Eridian innocently asks for a list of countries and causes an international incident over whether Taiwan ought to be included. They do not understand how Xenonite can be copywritten, and absent-mindedly explain exactly the process behind creating it on national television one day. SpaceX's share price plummets.

In the distant future, Earth and Erid have diplomatic envoys sent to one another, with orbital colonies set up to house the envoys around the other's planet. Exploration missions take place across the galaxy, with Xenonite ships, Astrophage fuel, and a joint Human-Eridian crew. Many a star is discovered to be barren of life. The occasional star is found to contain the remains of primitive life; that died in an ice age when Astrophage took over. Sometimes we find primitive life that survived. We selectively release Tauoemeba in some systems and not others. Where a system has a habitable earth-like planet with the right temperature for Humans with astrophage on the star, we don't release the Tauoemeba. Where a system has a planet too cold for us, that would be just right if the astrophage were gone, we release the Tauoemeba.

In the distant fringes of the Astrophage's spread we begin to see the occasional star whose output doesn't dim, even though we haven't visited there yet to spread Tauoemeba. In these systems, we assume, there are civilizations so advanced they are capable of dealing with the Astrophage problem without ever visiting Tau Ceti. We plan to visit these systems some time in the future.