Conceived in the 2000s, the first Cygnus pressurized cargo modules (PCM) were designed and built to ferry supplies to the International Space Station in the so-called standard version, with a payload capacity of 2,750 kg and a volume of 18 m3.
The Cygnus spacecraft comprises two main sections: a Service Module from Northrop Grumman, responsible for supplying the service to NASA, and a PCM developed and built by Thales Alenia Space. Cygnus typically makes two trips a year to the International Space Station, ferrying food, water, spares, repairs and science experiments to the crew.
This initial configuration was the norm until the Cygnus developed for the OA-4 mission. From the fifth mission onward, the design and cargo capacity evolved significantly, with a larger version, able to hold 3,750 kg and a volume of 27 m3. This enhanced configuration is the largest resupply capacity to the ISS, most recently used for the NG-20 mission at the end of January.
Inside Thales Alenia Space’s clean rooms, engineers are currently completing the Cygnus for NG-21, where final system verification and testing are underway to ready for delivery to Northrop Grumman in May of 2024. In the meantime, work continues to complete PCM 22, already undergoing integration in the clean room.