Cygnus (spacecraft)

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Cygnus spacecraft
Standard Cygnus vs Enhanced Cygnus.png

Scale drawing of the Standard (left) and Enhanced (right) Cygnus.
Description
Role: To be used to supply the International Space Station with cargo
Crew: 0
Carrier Rocket: Antares
Dimensions
Standard
Vehicle nos. 1–3		 Enhanced
Vehicle nos. 4+
Height:[1] 3.66 metres (12.0 ft) 4.86 metres (15.9 ft)
PCM diameter:[1] 3.07 metres (10.1 ft) 3.07 metres (10.1 ft)
Mass (dry):[1] 1,500 kilograms (3,300 lb) 1,800 kilograms (4,000 lb)
Volume:[2] 18.9 m3 (670 cu ft) 27 m3 (950 cu ft)
Delivered Payload:[2] 2,000 kilograms (4,400 lb) 2,700 kilograms (6,000 lb)
Disposal Payload: 1,200 kilograms (2,600 lb) 1,200 kilograms (2,600 lb)
Miscellaneous
Endurance: One week to two years[3]
Propellant: N2O4/MON-3[3]
Peak power: 3.5 kW[3]

The Cygnus spacecraft is an unmanned resupply spacecraft being developed by Orbital Sciences Corporation as part of NASA's Commercial Orbital Transportation Services (COTS) developmental program. It will be launched by Orbital's Antares rocket and is designed to transport supplies to the International Space Station (ISS) following the retirement of the American Space Shuttle. Since August 2000 unmanned ISS resupply missions have been regularly flown by Russian Progress spacecraft, as well as by the European Automated Transfer Vehicle, the Japanese H-II Transfer Vehicle, and the SpaceX Dragon. With the Cygnus spacecraft, NASA seeks to increase its partnerships with domestic commercial aviation and aeronautics industry.[4]

Contents

Development [edit]

NASA Administrator Charles Bolden (third from left) in front of the Cygnus spacecraft in May 2012

With Rocketplane Kistler unable to meet funding obligations for its K-1 launch vehicle under the terms of the COTS agreement, NASA decided on October 18, 2007 to terminate its contract with Rocketplane Kistler and re-award its contract after a competition.[5] On February 19, 2008 NASA announced that it had chosen Orbital Sciences as the new winner.[6] On December 23, 2008, NASA awarded Orbital Sciences a $1.9 billion contract under the Commercial Resupply Services (CRS) program. Under this contract, Orbital Sciences will deliver up to 20 tons of cargo to the ISS through 2016 in eight Cygnus spacecraft flights.[4]

By April 2010 Orbital had displayed a full-scale model of the Cygnus cargo delivery spacecraft at the National Space Symposium (NSS) in Colorado Springs, CO.[7]

Launched on an Antares (renamed from Taurus II) medium-class launch vehicle, the first Cygnus flight was originally planned to occur in December 2010.[8][9] In February 2013, it was reported that the launch of the Cygnus demonstration mission is not expected to occur until June 2013.[10]

Design [edit]

The Cygnus spacecraft consists of two basic components: the Pressurized Cargo Module (PCM) and the Service Module (SM). The PCM is manufactured by Thales Alenia Space, the initial PCMs have a volume of 18 m3.[11] The service module is built by Orbital and is based on their STAR spacecraft bus as well as components from the development of the Dawn spacecraft. It is currently expected to have a gross mass of 1,800 kg with propulsion provided by thrusters using the hypergolic propellants hydrazine and nitrogen tetroxide and is capable of producing up to 4 kW of electrical power via two gallium arsenide solar arrays.[11] On November 12, 2009, Dutch Space announced it will provide the solar arrays for the initial Cygnus spacecraft.[12]

The fourth Cygnus spacecraft and all after are planned to be of the "enhanced" variant.[13] These will use a stretched PCM which increases the interior volume to 27 m3 and the service module will use ATK Ultraflex solar arrays which will provide the same amount of power as the previous solar arrays but at a lower mass.[14][13] A new upper stage, the Castor 30XL, will be used in conjunction with the enhanced Cygnus; because of the more powerful upper stage and the lighter solar arrays, the payload Cygnus can deliver to the ISS will be increased by 700 kg.[14][15]

During nominal Cygnus CRS missions, it will maneuver close to the International Space Station where the Canadarm2 robotic arm will grapple the spacecraft and berth it to a Common Berthing Mechanism on the Harmony module in a similar fashion to the Japanese H-II Transfer Vehicle and the other American CRS vehicle, the SpaceX Dragon.[11] For typical missions, Cygnus is planned to remain berthed for about 30 days.[16][17] Cygnus does not provide return capability, but can be loaded with obsolete equipment and trash for destructive reentry similar to the Russian Progress vehicles.[18]

A formerly planned variant of Cygnus would have replaced the PCM with the Unpressurized Cargo Module (UCM), based on NASA's ExPRESS Logistics Carrier, and would have been used to transport unpressurized cargo, such as ISS Orbital Replacement Units.[8][19] Another proposed variant would have replaced the PCM with the Return Cargo Module (RCM), which would have allowed Cygnus to return cargo to Earth.[8]

Missions [edit]

List includes only currently manifested missions. All missions are currently planned to be launched from Mid-Atlantic Regional Spaceport Launch Pad 0A.

Mission name Launch date Cygnus type Rocket Remarks
Orbital Sciences COTS Demo Flight[citation needed] June 2013[10] Standard[15] Antares 110[15] First Cygnus mission, first mission to rendezvous with ISS, first mission to berth with ISS, second launch of Antares
Orb CRS-1 2013[20] Standard[15] Antares 120[15] First Cygnus Cargo Resupply Mission (CRS), first Antares launch to use the Castor 30B upperstage[15]
Orb CRS-2 2013[15][21] Standard[15] Antares 120[15]
Orb CRS-3 2013[15] Standard[15] Antares 130[15] First Antares launch to use Castor 30XL upperstage[15]
Orb CRS-4 2014[15][21] Enhanced[15] Antares 130[15] First Enhanced Cygnus mission[15]
Orb CRS-5 Enhanced[15] Antares 130[15]
Orb CRS-6 2015[21] Enhanced[15] Antares 130[15]
Orb CRS-7 Enhanced[15] Antares 130[15]
Orb CRS-8 2016[21] Enhanced[15] Antares 130[15]

See also [edit]

References [edit]

  1. ^ a b c "Thales Alenia Space — Cygnus". Thalesaleniaspace-issmodules.com. Retrieved 2011-03-01. 
  2. ^ a b "Cygnus Fact Sheet - 2012" (PDF). Retrieved 2012-04-01. 
  3. ^ a b c "The Annual Compendium of Commercial Space Transportation: 2012". Federal Aviation Administration. February 2012. Retrieved 8 February 2013. 
  4. ^ a b "NASA Taps SpaceX, Orbital Sciences to Haul Cargo to Space Station". Space.com. 2008-12-23. Retrieved 2011-03-01. 
  5. ^ "Time Runs out for RpK; New COTS Competition Starts Immediately". Space.com. 2007-10-19. Retrieved 2011-03-01. 
  6. ^ NASASpaceflight.com — Orbital beat a dozen competitors to win NASA COTS contract
  7. ^ "Orbital Unveils Full Scale Cygnus Model". 
  8. ^ a b c "Space Act Agreement with NASA and Orbital for COTS". NASA. 2008-02-27. Retrieved 30 March 2012. 
  9. ^ "Orbital Sciences To Build Taurus II". AviationWeek.com. Retrieved 2011-03-01. 
  10. ^ a b "Worldwide launch schedule". spaceflightnow.com. Retrieved 2013-02-12. 
  11. ^ a b c "Cygnus Spacecraft factsheet at Orbital.com" (PDF). Retrieved 2011-03-01. 
  12. ^ Peter B. de Selding (2009-11-12). "Dutch Space to Build Solar Arrays for Orbital’s Cygnus Cargo Tug". Space News. 
  13. ^ a b "Cygnus Enhanced Spacecraft to Use Ultraflex™ Solar Arrays". Orbital Sciences. November 2011. Retrieved 30 March 2012. 
  14. ^ a b "Cygnus™ Advanced Maneuvering Spacecraft Fact Sheet". Orbital Sciences. 2012. Retrieved 30 March 2012. 
  15. ^ a b c d e f g h i j k l m n o p q r s t u v w x y Bergin, Chris (2012-02-22). "Space industry giants Orbital upbeat ahead of Antares debut". NasaSpaceflight (not affiliated with NASA). Retrieved 29 March 2012. 
  16. ^ "NASA Advisory Council Space Operations Committee". NASA. 2010-07. Retrieved 15 April 2012. 
  17. ^ "Antares A-ONE Pre-flight Briefing". NASA. 16 April 2013. Retrieved 22 April 2013. "Typical mission will be about 30 days, including the rendezvous, the time aboard station, the time to de-orbit. We could extend that to 60 or 90 at NASA’s request, however once we separate from the space station, the spacecraft itself, depending on its fuel load could probably fly easily for another year, in terms of what the components are certified for." 
  18. ^ "Cygnus Advanced Manoeuvring Spacacecraft Fact Sheet". European Space Agency. 2010-09-01. Retrieved 2 April 2012. 
  19. ^ Whitesides, Loretta (2008-02-20). "Orbital Sciences Scores NASA’s Commercial Orbital Transportation Services (COTS) Award Worth $170M". Wired. Retrieved 30 March 2012. 
  20. ^ "Antares home page". Orbital Sciences. July 2012. Retrieved 19 July 2012. 
  21. ^ a b c d "Cygnus Missions". Orbital Sciences. Retrieved 26 June 2012. 
  22. ^ . Flight is automatic, it is manually captured by ISS robotic arm and berthed to the station. Dragonlab datasheet, v.2.1, 2009-09-18. accessed 2011-01-02.

External links [edit]

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