Cygnus OA-8E

File:Orbital ATK CRS-8 Launch (NHQ201711120006).jpg

The COTS demonstration mission was successfully conducted in September 2013, and Orbital commenced operational ISS cargo missions under the Commercial Resupply Service (CRS) program with two missions in 2014. Regrettably, the third operational mission, CRS Orb-3, was not successful due to spectacular Antares failure during launch. The company decided to discontinue the Antares 100 series and accelerate the introduction of a new propulsion system. The Antares system has been upgraded with newly built RD-181 first-stage engines to provide greater payload performance and increased reliability.

In the meantime, the company had contracted with United Launch Alliance for an Atlas V launch of CRS OA-4 in late 2015 from Cape Canaveral, Florida and with a second Atlas V Cygnus launch in 2016. The company had planned Cygnus missions for the first (CRS OA-5), second (CRS OA-6) and fourth quarters (Cygnus OA-7) of 2016. Two of these flew on the new Antares 230 and one on the aforementioned second Atlas V. These three missions enabled Orbital ATK to cover their initial CRS contracted payload obligation. This particular mission, is known as OA-8E, is part of an extension program that will enable NASA to cover the ISS resupply needs until the Commercial Resupply Services-2 (CRS-2) contract enters in effect. It is called OA-8E rather than OA-8, because the switch to a mix of Atlas V and the more powerful Antares 230 enabled the company to cover its original contract with just 7 flights, even counting the Orb-3 failure, and thus the E indicates that it actually is an extension above the originally contracted payload transport.

Production and integration of Cygnus spacecraft is performed in Dulles, Virginia. The Cygnus service module is mated with the pressurized cargo module at the launch site, and mission operations are conducted from control centers in Dulles, Virginia and Houston, Texas.

The launch was previously scheduled for 10 November 2017 at 13:03{{nbsp}}UTC before being moved to 11 November 2017 at 12:37:24{{nbsp}}UTC. The 11 November 2017 launch attempt resulted in a twenty-four hour recycle due to a plane flying into the restricted area with less than a minute into the count. The Antares rocket launched the 8th Cygnus cargo vehicle on Sunday 12 November 2017 at 12:19:51{{nbsp}}UTC.

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This was the eighth of ten flights by Orbital ATK under the Commercial Resupply Services contract with NASA, and is considered an extension over the originally contracted flights. This was the fifth flight of the enhanced-sized Cygnus PCM.

In an Orbital ATK tradition, this Cygnus spacecraft was named the S.S. Gene Cernan after one of NASA's Apollo astronauts, Apollo 17 commander Eugene Cernan (1934-2017), the last man (as of 2020) to walk on the Moon and one of only three humans to visit the Moon (in orbit or on the surface) twice.{{cite web|url=https://www.orbitalatk.com/news-room/feature-stories/OA8-Mission-Page/Documents/SS_Gene%20Cernan_Bio.pdf|title=S.S. Gene Cernan OA-8 Cargo Delivery Mission to the International Space Station|access-date=14 November 2017|publisher=orbital ATK|archive-date=26 October 2017 |archive-url=https://web.archive.org/web/20171026054359/https://www.orbitalatk.com/news-room/feature-stories/OA8-Mission-Page/Documents/SS_Gene%20Cernan_Bio.pdf|url-status=dead}}

Total cargo mass: {{cvt|3338|kg}}{{cite web|url=https://www.nasa.gov/sites/default/files/atoms/files/orbital_atk_crs-8_overview.pdf|title=Overview: Orbital ATK CRS-8 Mission |publisher=NASA|access-date=22 April 2018}} {{PD-notice}}

• Pressured cargo with packaging: {{cvt|3229|kg}}
• Crew supplies: {{cvt|1240|kg}}
• Science investigations: {{cvt|740|kg}}
• Spacewalk equipment: {{cvt|132|kg}}
• Vehicle hardware: {{cvt|851|kg}}
• Computer resources: {{cvt|34|kg}}
• Unpressurized cargo: {{cvt|109|kg}}

• Uncrewed spaceflights to the International Space Station

{{Reflist|30em|refs=

{{cite web|url=http://www.nasaspaceflight.com/2012/02/orbital-upbeat-ahead-of-antares-debut/|title=Space industry giants Orbital upbeat ahead of Antares debut|last=Bergin|first=Chris |date=22 February 2012|publisher=NASASpaceFlight.com|access-date=29 March 2012}}

{{cite web|url=http://www.nasaspaceflight.com/2015/08/orbital-atk-progress-return-antares/|title=Orbital ATK make progress toward Return To Flight of Antares rocket|last=Gebhardt |first=Chris|date=14 August 2015|publisher=NASASpaceFlight.com|access-date=14 August 2015}}

{{cite web|url=https://www.orbitalatk.com/space-systems/human-space-advanced-systems/commercial-resupply-services/docs/FS006_08_OA_3891%20Cygnus.pdf|title=Cygnus Fact Sheet |publisher=Orbital ATK|date=24 March 2015|access-date=14 August 2015|url-status=dead|archiveurl=https://web.archive.org/web/20150926095427/http://www.orbitalatk.com/space-systems/human-space-advanced-systems/commercial-resupply-services/docs/FS006_08_OA_3891%20Cygnus.pdf|archive-date=26 September 2015}}

{{cite web|url=http://www.orbitalatk.com/news-room/feature-stories/CRSUpdate/default.aspx|title=Orbital ATK Team on Track for Fall 2015 Cygnus Mission and Antares Return to Flight in 2016|publisher=Orbital ATK|date=12 August 2015|access-date=12 August 2015}}

{{cite web|url=http://spacenews.com/nasa-orders-two-more-iss-cargo-missions-from-orbital-atk/|title=NASA Orders Two More ISS Cargo Missions From Orbital ATK|last=Leone|first=Dan |publisher=SpaceNews|date=17 August 2015|access-date=17 August 2015}}

{{cite web|url=http://spacenews.com/nasa-considering-more-cargo-orders-from-orbital-atk-spacex/|title=NASA Considering More Cargo Orders from Orbital ATK, SpaceX|last=Leone|first=Dan |publisher=SpaceNews|date=20 August 2015|access-date=20 August 2015}}

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Category:Cygnus (spacecraft)

Category:Spacecraft launched by Antares rockets

Category:Spacecraft launched in 2017

Category:Spacecraft which reentered in 2017

Category:Supply vehicles for the International Space Station

Category:Gene Cernan