An Overview of the Cygnus Mission to ISS

Illustration of Cygnus in orbit. (Credit: Orbital Sciences Corporation)

Cygnus Mission Summary

Company: Orbital Sciences Corporation
Launch Vehicle: Antares
Payload: Cygnus cargo freighter
Destination: International Space Station
Launch Date: Wednesday, Sept. 18, 2013
Berthing at ISS:  Sunday, Sept. 22, 2013
Launch Site: Mid-Atlantic Regional Spaceport (MARS), Wallops Island, Virginia
Orbit: LEO
Program: NASA Commercial Orbital Transportation Systems (COTS)
Mission Description: Inaugural test flight of the first Cygnus cargo freighter to the International Space Station under NASA’s COTS program. Cygnus will carry 1,300 lbs. of cargo to astronauts aboard the orbiting laboratory.

Mission Coverage

A post-launch news conference is scheduled for 12:30 p.m. EDT/9:30 a.m. PDT.  It will be broadcast live on NASA Television.

On Sunday, Sept. 22, NASA Television coverage of rendezvous will begin at 4:30 a.m. and will continue through the capture and installation of the Cygnus spacecraft. Capture is scheduled for about 7:17 a.m. EDT with installation of the craft beginning about 9 a.m.

At about 1 p.m. EDT, after Cygnus operations are complete, a joint news conference will take place at Johnson and at Orbital’s Headquarters at 45101 Warp Drive in Dulles, Va. The briefing will be carried live on NASA Television and the agency’s website.

Cygnus Freighter

The Cygnus spacecraft is composed of two elements with spaceflight heritage. The Service Module incorporates avionics systems from Orbital’s LEOStar and GEOStar satellite product lines as well as propulsion and power systems from the company’s GEOStar communications satellites.

The Pressurized Cargo Module (PCM) is produced by Thales Alenia Space in Torino, Italy. The PCM is based upon Thale’s Multi-Purpose Logistics Modules (MPLM), which space shuttles carried to the International Space Station (ISS) filled with supplies. One of the MPLMs was refitted and permanently docked to ISS.

Other non-U.S. suppliers include Mitsubishi Electric Corporation (MELCO) of Tokyo for the Proximity Location System and Dutch Space of the Netherlands for its solar arrays. Partners also include:

• Draper Laboratory, guidance, navigation and fault tolerant computer support;
• Odyssey Space Research, visiting vehicle requirements support;
• JAMSS America, operations support; and,
• Vivace, systems engineering support.

Cygnus is carrying 1,300 lbs. of cargo to ISS. The flight is being done under the NASA-funded Commercial Orbital Transportation Services (COTS) program.

If the flight is successful, Orbital will begin a series of eight cargo runs to the station under the space agency’s Commercial Resupply Services (CRS) program. NASA will pay about $1.9 billion for the flights.

The initial deliveries will feature a standard cargo module with an interior volume of 18.9 cubic meters that will be capable of delivering 2,000 kg of cargo to ISS. Missions four through eight will feature an enhanced cargo module with a volume of 27 cubic meters and improved solar panels that will deliver up to 2,700 kg to the orbiting facility. In all, Orbital is contracted to deliver 20,000 kg to the station.

Cygnus Specifications

Service Module Heritage: GEOStar, LEOStar
Power Generation: 2 fixed wing solar arrays, ZTJ Gallium Arsenide cells
Power Output: 3.5 kW (sun-pointed)
Propellant: Dual-mode N₂H₄/MON-3 or N₂H₄
Pressurized Cargo Module Heritage: Multi-Purpose Logistics Module
Total Cargo Mass: 2,000 kg Standard/2,700 kg Enhanced
Pressurized Volume: 18.9 m³Standard/27 m³ Enhanced
Berthing at ISS: Node 2 Common Berthing Mechanism (CBM)