S.S. Roger Chaffee at the Space Station
|Mission type||ISS resupply|
|Spacecraft||S.S. Roger Chaffee|
|Spacecraft type||Enhanced Cygnus|
Thales Alenia Space
|Start of mission|
|Launch date||17 April 2019, 20:46:07 UTC|
|Launch site||MARS LP-0A|
|Berthing at ISS|
|Berthing port||Unity nadir|
|RMS capture||19 April 2019 09:28 UTC|
|Berthing date||19 April 2019 11:31 UTC|
|Unberthing date||23 July 2019 (planned)|
|RMS release||23 July 2019 (planned)|
|Mass||3,436 kg (7,575 lb)|
|Pressurised||3,162 kg (6,971 lb)|
|Unpressurised||239 kg (527 lb)|
Cygnus NG-11, previously known as CRS OA-11, is the twelfth flight of the Northrop Grumman robotic resupply spacecraft Cygnus and its eleventh flight to the International Space Station under the Commercial Resupply Services contract with NASA. The mission launched on 17 April 2019 at 4:46 PM EDT (20:46 UTC). This is the last mission from the extended CRS contract; followup missions are part of the CRS2 contract. NG-11 was also the first mission to utilize the Antares twenty four hour prior load where critical hardware could be loaded into Cygnus just twenty four hours prior to launch.
Orbital ATK and NASA jointly developed a new space transportation system to provide commercial cargo resupply services to the International Space Station (ISS). Under the Commercial Orbital Transportation System (COTS) program, then Orbital Sciences designed and built Antares, a medium-class launch vehicle; Cygnus, an advanced maneuvering spacecraft, and a Pressurized Cargo Module which is provided by Orbital's industrial partner Thales Alenia Space. Northrop Grumman purchased Orbital in June 2018; its ATK division was renamed Northrop Grumman Innovation Systems. Concurrently Nepalese satellite NepaliSat-1 and a Sri Lankan satellite Raavana 1 were launched as part of Cygnus NG-11 to the space.
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, Orb CRS-3, resulted 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. The Antares system will be 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, FL, 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 (CRS OA-7) of 2016. Two of which 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, known as NG-11, is part of an extension program that will enable NASA to cover the ISS resupply needs until the Commercial Resupply Services 2 contract enters in effect, 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 and Houston.
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 and Houston. This will be the eighth flight of the Enhanced-sized Cygnus PCM.
The spacecraft for the NG-11 is named the S.S. Roger Chaffee after Roger Chaffee who lost his life during training for the Apollo 1 mission.  On 17 April 2019 at 4:46:07 PM EST, Antares launched the NG-11 mission to the International Space Station from Wallops Island, Virginia.
Total weight of cargo: 3,436 kg (7,575 lb), consisting of 3,162 kg (6,971 lb) in pressurised cargo and 239 kg (527 lb) in unpressurized cargo.
- Crew supplies
- Science investigations
- Spacewalk equipment
- Vehicle hardware
- Computer resources
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- SatRevolution's CubeSat - Światowid
- KRAKsat - CubeSat created by Polish students from AGH University of Science and Technology and Jagiellonian University  in cooperation with SatRevolution
- AeroCube 10A/10B by Aerospace Corporation 
- BIRDS 3
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- SASSI2 3U Cubesat by University of Illinois and Purdue University School of Aeronautics and Astronautics
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