Orbital Sciences Hits Key Milestones Toward ISS Cargo Flights


Cygnus modules in preparation for flight. (Credit: Orbital Sciences Corporation)

An update from Orbital Sciences Corporation:

As the year draws to a close there are now three substantially complete Cygnus Service Modules in Orbital’s Dulles, Virginia Satellite Manufacturing Facility (see photo below). In addition to the integration and testing of the spacecraft, the program has achieved a number of key milestones in the last few months:

Mission Operations to Spacecraft Testing: The Orbital team successfully completed the first test of the Mission Operations to Spacecraft link. The COTS demo service module was attached via data and command lines to Orbital’s Mission Operations Center in Dulles, Virginia, and the mission timeline from launch to berthing was exercised by the Cygnus team. This test required the team to operate in shifts, flying the spacecraft continuously for approximately 80 hours to simulate all required maneuvers to achieve ISS berthing, successfully executing all required procedures.

Safety Review: In addition, the Cygnus engineering and safety teams successfully completed the presentation of our final safety hazard assessment to the ISS Safety Review Panel, including design and operational controls to mitigate hazards to the Space Station or its Crew.

Joint Avionics Software Validation Testing: At the Johnson Space Center (JSC) Orbital connected its Cygnus “Flatsat” to a ISS “Flatsat” platform to validate the avionics that comprise the spacecraft and the Cygnus ground control system. Joint Test 4 (JT4) validated Cygnus interfaces to the ISS successfully demonstrating its ability to send commands and receive telemetry. Cygnus flight software also demonstrated nominal and off-nominal approaches, nominal departures, aborts, and a wide variety of responses to faults.

Joint Test 5, also known as the End-to-End-Test, used the same test configuration and included mission control centers in Houston, Texas, Dulles, Virginia, and Tskuba, Japan to validate the ability of the distributed ground control system to properly operate ISS and Cygnus. The team passed all test cases on the first pass with no issues.