Minimize ISS: Cygnus CRS Orb-2

ISS Utilization: Cygnus CRS Orb-2

Overview    Spacecraft    Launch    Mission Status    References

This is the second of eight scheduled flights by Orbital Sciences under the CRS (Commercial Resupply Services) contract with NASA. In an Orbital Sciences tradition, the Cygnus spacecraft has been named the Janice Voss after the NASA astronaut and Orbital employee who passed away on February 6, 2012.

The objective of Orb-2 is to deliver more than 1.5 metric tons of supplies, experiment materials and hardware to the Station - building on the success of the previous Antares & Cygnus missions.

Cygnus made its first operational mission in January/February 2014, becoming part of an international fleet of resupply craft that make regular visits to the International Space Station to keep it supplied with scientific experiments, maintenance materials and consumables for the six crew members.

Under a $1.9 billion CRS contract with NASA, Orbital will use Antares and Cygnus to deliver up to 20,000 kg of cargo to the ISS over eight missions, including the mission currently underway, through late 2016. For these missions, NASA will manifest a variety of essential items based on ISS program needs, including food, clothing, crew supplies, spare parts and equipment, and scientific experiments.


Figure 1: Cygnus spacecraft at the Wallops Island, Virginia launch site (image credit: Orbital)


Cygnus is an unmanned cargo resupply spacecraft that is designed and operated by Orbital Sciences to transport pressurized cargo to the International Space Station. Cygnus consists of a Pressurized Cargo Module that is built by TAS-I (Thales Alenia Space-Italia) and a Service Module built by Orbital, based on Orbital's GEOStar Satellite Bus and Dawn spacecraft elements to reduce cost and risk. Cygnus is not capable of returning cargo to Earth and burns up on reentry to dispose of itself and no-longer-needed items from ISS. 1) 2)

The mission partners of OSC (Orbital Sciences Corporation) are:

1) TAS-I (Thales Alenia Space-Italia): Pressurized cargo module

2) MELCO (Mitsubishi Electric Corporation): Proximity link system

3) Draper Laboratory: Guidance, navigation and fault tolerant computer support

4) Odyssey Space Research: Visiting vehicle requirements support

5) JAMSS (Japan Manned Space Systems Corporation) America, Inc.: Operations support

6) Vivace: Systems engineering support.

The Orb-2 mission is delivering 1,657 kg of cargo to the ISS (International Space Station) including a number of science payloads, resupply items, food provisions, systems hardware and personal items for the crew members.


Launch: The Cygnus CRS Orb-2 spacecraft was launched on July 13, 2014. The launch vehicle was Antares-120 of OSC and the launch site was MARS (Mid-Atlantic Regional Spaceport), Wallops Island, VA. 3)

Orbit: Near-circular orbit , initial altitude of about 350-400 km, inclination 51.6º.

The secondary payloads on the Cygnus CRS Orb-2 mission were: 4)

• Planet Labs’ Flock-1b: A flock of 28 nanosatellites (additional to 28 Flock-1 nanosatellites launched on January 9, 2014) from Planet Labs of San Francisco are aboard to take pictures of Earth. After deployment from the Japanese JEM module (using the NanoRacks LLC Smallsat Deployment Program). Once deployed, these two flocks will work in unison and capture imagery of the entire planet on a more frequent basis, forming the largest constellation of imaging satellites in Earth orbit. 5) 6)

• TechEdSat-4 is a small CubeSat, built by NASA/ARC (Ames Research Center) in California that will investigate technology to return small samples to Earth from the space station. TechEdSat-4 will deploy using the NanoRacks services. Its primary objectives are to further develop a tension-based drag device, called exo-brake, and demonstrate frequent uplink/downlink control capabilities.

• MicroMAS-1 (Microsized Microwave Atmospheric Satellite-1), a 3U CubeSat of MIT/LL (Massachusetts Institute of Technology/Lincoln Laboratory). The objective is to provide unprecedented observations of hurricanes and tropical storm dynamics.

• GEARSSAAT, a CubeSat with a Globalstar communications terminal. The objective is to study the Globalstar communications constellation.

• LambdaSat, a 1U Cubesat developed and operated by the Lambda Team, an international group including Greek scientists and students from San Jose, USA. The objective is to measure radiation effects on graphene material in LEO, and tracking vessels with an AIS receiver inside its footprint around the globe.

• Fifteen student experiments of the “Charlie Brown” mission are aboard and hosted by the SSEP (Student Spaceflight Experiment Program), an initiative of NCESSE (National Center for Earth and Space Science Education) and NanoRacks. They will investigate plant, lettuce, raddish and mold growth and seed germination in zero-G, penecilium growth, corrosion inhibitors, oxidation in space and microencapsulation experiments.

• Ten internal payloads from NanoRacks’ customers are holding dozens of research experiments onboard.

• SPHERES (Smart Synchronized Position Hold, Engage, Reorient Experimental Satellites) experiment of NASA/ARC features a sensor and multiple cameras to enable 3-D mapping and robotic navigation inside the space station.


Figure 2: Photo of the Cygnus spacecraft after it was grabbed by the Canadarm2 (image credit: NASA)



Mission status:

• The flight of the Orbital Sciences’ Cygnus commercial cargo carrier concluded on August 17, 2014 in a spectacular fireball as planned upon reentry into Earth’s atmosphere at approximately 13:15 GMT . The fireworks were captured for posterity in a series of amazing photos taken by the Expedition 40 crew aboard the ISS. 7)

- ESA astronaut Alexander Gerst and Russian Cosmonaut Maxim Suraev documented the breakup and disintegration of Cygnus over the Pacific Ocean east of New Zealand, following precise thruster firings commanded earlier by Orbital Sciences mission control in Dulles, VA, that slowed the craft and sent it on a preplanned destructive reentry trajectory.


Figure 3: Image of the Cygnus spacecraft reentry into Earth's atmosphere on August 17, 2014 (image credit: NASA/ESA/Alexander Gerst)

• On August 15, 2014, the Cygnus commercial cargo ship ‘Janice Voss’ of Orbital Sciences finished it’s month-long resupply mission and bid farewell to the International Space Station, after station astronauts released the vessel from the Canadarm2 robotic arm. The release took place when the ISS was flying over the west coast of Africa (the coastline of Namibia). 8)

- About 2 minutes after release, Cygnus fired its thrusters to depart the station and head toward a destructive fiery reentry into the Earth’s atmosphere over the Pacific Ocean on August 17, 2014.


Figure 4: The Cygnus Orb-2 spacecraft ‘Janice Voss’ departed ISS at 10:40 GMT on Aug. 15, 2014 (image credit: NASA TV, Ref. 8)

• On July 16, 2014, Orbital's Cygnus spacecraft successfully completed its rendezvous and approach maneuvers with the ISS and was grappled and berthed with the station's robotic arm (Canadarm2) by the Expedition 40 astronaut crew. Cygnus will remain berthed at the ISS for 30 days before departing with approximately 1,300 kg of disposable cargo. Orbital will also conduct a series of in-orbit tests designed to provide data to help improve the vehicle’s performance for future uses. At the end of the mission Cygnus will reenter the Earth’s atmosphere (Ref. 3).


1) “Cygnus™ Cargo Delivery Spacecraft for the International Space Station (ISS),” Orbital, URL:

2) “Orbital-2 Mission to the International Space Station,” NASA, Media Press Kit, July 2014, URL:

3) “ISS Commercial Resupply Services Mission (Orb-2),” Orbital, July 13, 2014, URL:

4) Patrick Blau, “Cygnus Orb-2 Cargo Manifest,” Spaceflight 101, URL:

5) “Orbital Sciences’ Successfully Berthed Cygnus to ISS in Second Resupply Mission,” NanoRacks Press Release, July 16, 2014, URL:

6) “Spaceflight, NanoRacks Partnership Launches Additional Planet Labs Flock Onboard Orbital Sciences’ Orb-2 Mission,” Spaceflight Inc., July 16, 2014, URL:

7) Ken Kremer, “Cygnus Cargo Carrier Concludes with Fiery Reentry Aug. 17 – Amazing Astronaut Photos,” Universe Today, August 17, 2014, URL:

8) Ken Kremer, “Cygnus Commercial Cargo Ship ‘Janice Voss’ Finishes Resupply Mission and Departs Space Station,” Universe Today, August 15, 2014, URL:

The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: ”Observation of the Earth and Its Environment: Survey of Missions and Sensors” (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (

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