Unified Power Standards to Reduce Space Station Load
The International Space Station (ISS) faced a practical challenge during its early construction: how to simplify the laptop charging process. In the late 1990s, NASA’s engineering team decided to repurpose the unused modem ports on laptops into unified power connectors, adopting the 'cannon plug' as the standard to directly interface with the station’s direct current (DC) power system. This modification not only reduced the need for multiple chargers but also lowered the risk of equipment failure and effectively decreased the station’s overall weight.
The laptops sent to the ISS at the time were primarily models like the ThinkPad. Since the ISS did not utilize traditional telephone modems, these ports were removed and redesigned as charging ports. NASA engineer George Roush explained that the modification allowed astronauts and visitors to directly tap into the station’s power supply without carrying various charging devices. He noted that this historical detail has rarely been discussed externally, and related documentation has gradually faded over time.
Military-Grade Communication Standard Replaces Ethernet
The ISS’s networking and communication systems did not adopt the commonly used Ethernet standard for computers. Instead, it relied on the military-grade MIL-STD-1553 standard. This design reflected the technological context of the space station’s construction era, when modems were still a standard feature in personal computers. By the time the first astronauts arrived at the ISS in 2000, this system was already in operation, becoming one of the station’s critical infrastructure components.