Passages through wormholes had been closed intermittently even before the Cold War. Most were closed because of stability problems or because maintenance was discontinued when they were no longer economically viable. After the Third Passage Mandate Act and the Return Eligibility Ruling, however, the number of reserve passages justified on safety grounds actually increased, while closures for economic reasons virtually disappeared. Entrances to passages that had collapsed or suffered accidents were repaired, and if they could not be repaired, new entrances were installed. The maintenance, repair, and replacement of passages had itself become a vast industry that generated new demand. For that reason, there was no universal agreement on a plan to stop maintaining passages that were still functioning normally.
When the Energy Conservation Committee aggregated the usage rates of registered passages, more than half had recorded no traffic for an entire year. Some entrances had not been used by anyone for thousands of years. Equipment that stabilized the throat, calculated time differences, and waited for emergency signals continued to consume power. The committee reported that redirecting the energy used by passages with no users could supply enough power to support the lives of hundreds of billions of people. Abandoned tourist planets, planets containing only exhausted mines, numerous planets humans had left behind, and third passages that had never been used were placed on the list of closure candidates. The Central Union government accepted four conditions proposed by an advisory group from the Life Protection Coalition and announced formal closure criteria. A passage could be considered for closure only if it had no traffic record for one thousand years, no local residents, no identified return-eligible persons, and another passage capable of replacing it. If even one condition was not satisfied, the passage remained open. The first review examined 960,000 passages. Only 518 passed. Old passenger lists, unrestored memory records, and records stating an intention to return became grounds for return-eligibility review. Even establishing that no residents remained was difficult. Independently living beings underground and in planetary orbit also had to be investigated. Safely closing a passage was expensive as well. Residual energy in the throat had to be dealt with, and the time difference between the two entrances had to be taken into account. An improperly closed passage could disturb the stabilization fields of neighboring passages. At some entrances, the closure operation required the equivalent of several hundred years of maintenance costs. The committee calculated that the energy saved over the long term would exceed that cost. Of the 518 passages, one hundred considered low risk were selected for the first trial closures. The first target was a satellite belonging to a weather station that had ceased operation long ago. It had recorded no traffic for three thousand years and no signs of life were detected. Descendants of the former staff claimed a right to visit the place where their ancestors had lived. The government copied the station’s records, conducted a remote inspection of the interior, and rejected the petition. It concluded that preserving a place was different from maintaining a wormhole to that place forever. The passage was closed as scheduled without incident. Eleven more passages were then closed safely, and the energy saved was supplied to other settlements. Support for the plan increased even in regions that had opposed it.
While the thirteenth passage was being closed, the monitoring system at the far-side entrance detected an old call sign. The signal was being transmitted by a slow ship that had departed 871 years earlier. The ship was navigating automatically toward the star system containing the entrance and had seventeen years remaining before arrival. Seven hundred passengers aboard were in cryogenic sleep. An order was issued to stop the closure. The throat, however, had already been narrowed, and expanding it again carried a risk of collapse. Engineers considered ways to preserve the existing entrance and to transport an entrance for a new passage. The new entrance would require forty-three years to arrive. Seventeen years later, the ship reached the location where the closed entrance had once been. Its remaining energy could sustain it for another eleven years. The rescue ship arrived twenty-six years after the stranded vessel. The passengers had died fifteen years before the rescue ship arrived. The investigation found that the departure record had been included in the data used for the closure review. The destination star had been renamed four times over the preceding 871 years, and the search system had failed to classify the different names as the same location. The closure condition requiring that there be no known traveler had therefore not been satisfied. The responsible agency and all three verification committees had nevertheless completed the searches required by the regulations then in force.
The remaining trial closures were suspended. The administrator who had approved the plan was also investigated. He had neither omitted any criteria nor concealed any data. The record used a different name, and the procedure linking names to coordinates had not incorporated the changes. After the incident, the legislature strengthened the review process. The no-traffic period was extended from one thousand years to ten thousand years. All former star names and coordinates had to be cross-checked, and the possibility of unidentified travelers had to be evaluated by multiple independent systems. No passage was found that met the new standards. The Energy Conservation Committee proposed, instead of closure, maintaining a small throat under normal conditions and expanding it when an approach signal was detected. Maintenance costs fell temporarily, but emergency-expansion equipment and signal-prediction systems were required. Once the technology stabilized, small passages could be installed even at locations that had previously been considered uneconomical to connect. More passages were opened than had been closed under the trial program.
The alliances that had opposed closure submitted the records of the missing ship’s passengers to the Central Union government and the relevant institutions. Yet support for keeping passages open was not universal. There were also records of settlements that survived because they received the energy saved by the closures. The same plan had both saved lives and caused lives to be lost. Neither set of records was deleted. After the passage-closure plan, politicians began using terms such as “long-term standby” and “suspension of operations” instead of “closure.” Even changing the name did not result in approval to eliminate a throat completely. Permanent closure and the temporary closing of a passage by safety systems during an accident remained distinct acts under the regulations. That distinction later became important during the Zero-Latency Disaster. Systems that temporarily closed passages in response to danger warnings still functioned, but permanently eliminating a normally operating passage required extensive verification.