![]() Enhanced Cygnus spacecraft approaching the International Space Station for the NG-12 mission | |
Manufacturer |
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Country of origin | United States |
Operator |
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Applications | ISS logistics |
Specifications | |
Spacecraft type | Uncrewed cargo vehicle |
Dry mass | Standard: 1,500 kg (3,300 lb) Enhanced: 1,800 kg (4,000 lb) [1] |
Payload capacity | Standard: 2,000 kg (4,400 lb) Enhanced: 3,500 kg (7,700 lb) [1] Mission B: 5,000 kg (11,000 lb) [2] |
Volume | Standard: 18.9 m3 (670 cu ft) Enhanced: 27 m3 (950 cu ft) [1] Mission B: 36 m3 (1,300 cu ft) [3] |
Power | 3.5 kW |
Design life | 1 week to 2 years [4] |
Dimensions | |
Length | Standard: 5.14 m (16.9 ft) Enhanced: 6.39 m (21.0 ft) [1] Mission B: 7.89 m (25.9 ft) [2] |
Diameter | 3.07 m (10.1 ft) [1] |
Production | |
Status | In service |
On order | 5 |
Built | 21 |
Launched | 20 |
Operational | 1 |
Retired | 18 |
Lost | 1 |
Maiden launch | 18 September 2013 |
Last launch | 4 August 2024 |
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Cygnus is an expendable American cargo spacecraft used for International Space Station (ISS) logistics missions. Cygnus was developed by Orbital Sciences Corporation, partially funded by NASA under the agency's Commercial Orbital Transportation Services (COTS) program. To create Cygnus, Orbital paired the Multi-Purpose Logistics Module, built by Thales Alenia Space and previously used by the Space Shuttle for ISS logistics, with a service module based on Orbital's GEOStar, a satellite bus. After a successful demonstration flight in 2013, Orbital was chosen to receive a Commercial Resupply Services (CRS) contract. A larger Enhanced Cygnus was introduced in 2015. Orbital Sciences was renamed Orbital ATK in 2015 and Northrop Grumman purchased Orbital in 2018 and has continued to operate Cygnus missions.
Cygnus is typically launched using its parent company's Antares rocket from the Wallops Flight Facility in Virgina, however it is able to fly on other launch vehicles. After the failure of an Antares rocket destroyed Cygnus CRS Flight 3 and damaged the Wallops facility, two Cygnus missions were launched with Atlas V rockets in 2015 and 2016. Additionally, three Cygnus missions are expected to be launched on the Falcon 9 rocket in 2024 and 2025, operated by CRS competitor SpaceX.
In addition to Cygnus, ISS logistics missions have been regularly flown by the Russian Progress spacecraft, the European Automated Transfer Vehicle, the Japanese H-II Transfer Vehicle and the American SpaceX Dragon.
Cygnus is the Latinized Greek word for swan and a northern constellation.
After the retirement of the Space Shuttle was announced, NASA began to look for commercial space launch companies who could fly cargo to the ISS. In early 2006, the agency started its COTS program, where it would help fund the development of cargo spacecraft after a competitive process. SpaceX and Rocketplane Kistler won contracts in the COTS program, however Rocketplane Kistler failed to meet several financial milestones and on 18 October 2007, NASA announced it would terminate its contract and re-award it after a second competition. [5] [6]
Orbital Sciences Corporation participated in this second round, proposing a largely "off-the-shelf" design. The spacecraft, named Cygnus, would be built around a service module based on Orbital's Star Bus, a satellite bus in use since 1997, which would be attached to a pressurized cargo container built by Thales Alenia Space, based on the Multi-Purpose Logistics Module it previously built for use by the Space Shuttle for ISS logistics.
Cygnus was awarded a COTS contract worth $170 million in February 2008, which was later increased to $288 million. On 23 December 2008, NASA awarded Orbital Sciences a $1.9 billion contract under the Commercial Resupply Services (CRS) program. Under this contract, Orbital Sciences agreed to deliver up to 20 tons of cargo to the ISS through 2016 in eight Cygnus spacecraft flights. [7]
To propel Cygnus into space, Orbital developed the Antares rocket with the Ukrainian KB Pivdenne design agency. To keep costs low, Antares was equipped with refurbished AJ-26 engines which were originally manufactured in the 1960s and 1970s for the Soviet Moon rocket.
The first Cygnus flight was originally planned to occur in December 2010, but was repeatedly delayed. [8] [9] The Antares made its maiden flight lifting a payload mass simulator to low Earth orbit on April 21, 2013. On September 18, 2013, Antares successfully launched a Cygnus spacecraft on a flight test to rendezvous with the International Space Station. [10] On 12 January 2014, the first scheduled Cygnus resupply mission arrived at the space station; the capsule carried Christmas presents and fresh fruit for the astronauts. Its arrival was delayed, first by the need to repair the station, and then by frigid weather at the launch site and solar flares that forced postponements. [10] [11]
With the December 2015 launch of Orb CRS-4 on Atlas V, the enhanced version of Cygnus made its debut. While it was planned from the beginning to fly on the fifth mission, the Orb CRS-3 failure and subsequent move to Atlas V meant a delay. However, lessons learned on packing and the extra capabilities of the Atlas allowed payload to be increased to 3,500 kg (7,700 lb). [12]
The Cygnus spacecraft consists of two basic components: the Service Module (SM) and the Pressurized Cargo Module (PCM).
The SM was based on prior products developed by Orbital including the GEOStar and LEOStar (collectively known as Star Bus) satellite buses and the Dawn spacecraft. It has a gross mass of 1,800 kg (4,000 lb), 32 thrusters for attitude control and one BT-4 main engine [13] burning 800 kg (1,800 lb) of hypergolic propellants hydrazine and nitrogen tetroxide. [14] [15] The SM is capable of producing up to 4 kW of electrical power via two solar arrays. [16] [17]
The PCM is manufactured by Thales Alenia Space in Turin, Italy. The first "Standard" PCMs had an empty mass of 1,500 kg (3,300 lb) [18] and a volume of 18 m3 (640 cu ft). [16]
The fourth and all subsequent Cygnus spacecraft are the "Enhanced" variant. [17] These have a stretched PCM with an empty mass 1,800 kg (4,000 lb), interior volume increased by 50% to 27 m3 (950 cu ft), and cargo capacity increased by 700 kg (1,500 lb). [19] To launch the added weight, Orbital used the more powerful Castor 30XL solid-fuel rocket as a second-stage.
During a typical CRS missions, Cygnus maneuvers close to the International Space Station, where the Canadarm2 robotic arm grapples the spacecraft and berths it to a Common Berthing Mechanism on the Harmony module. [16]
Cygnus does not provide cargo return capability. However, it can be loaded with obsolete equipment and trash which will burn up as the Cygnus makes a destructive reentry. [20]
An earlier proposed version 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] [21] 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]
In August 2023, Northrop Grumman announced a further enlarged Mission B version of Cygnus, with a 1.5 m (4.9 ft) stretch to the payload module and payload mass increased to 5,000 kg (11,000 lb). This version is expected to enter service with the NG-23 mission in 2025 (the first to use the new Antares 330 launch vehicle). [2]
In August 2019, NASA decided to sole source its design for the Minimal Habitation Module (Habitation and Logistics Outpost, or HALO) of the Lunar Gateway to Northrop Grumman Innovation Systems, which offered a minimalist 6.1 m (20 ft) by 3 m (9.8 ft) design based directly on the Enhanced Cygnus, as well as a larger 7 m (23 ft) by 4.4 m (14 ft) design [22] [23] having radial docking ports, body-mounted radiators (BMRs), batteries and communications antennas added on the outside. Northrop Grumman Innovation Systems opted to build the minimalist design, which offered the advantage of component compatibility and expedited testing of life support systems on existing Cygnus spacecraft. [24] [25] On 5 June 2020, NASA awarded Northrop Grumman Innovation Systems a $187 million contract to complete the preliminary design of HALO. NASA will sign a separate contract with Northrop for the fabrication of the HALO, and for integration with the Power and Propulsion Element (PPE), being built by Maxar. [24] [25]
The following list includes only missions that have flown and six planned missions. As of August 2024 [update] one mission is planned to be launched on the Falcon 9 rocket from Cape Canaveral Space Launch Complex 40, and three from Wallops on an Antares 330. Cygnus is the only cargo freighter to launch on four different launch vehicles: the Antares 100 series, Atlas V, Antares 200 series and Falcon 9 Block 5. [26] Each mission is named for a notable member of the Human spaceflight community.
# | Mission | Patch | Payload | Variant | Launch date (UTC) | Rocket | Payload mass | Outcome | Ref. |
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0 | Cygnus Mass Simulator | Cygnus Payload Simulator | — | 21 April 2013, 21:00:00 | Antares 110 | — | Success | [27] [28] | |
First Antares launch, demonstrated Antares's performance and capability to place its payload on a precise target orbit. [29] | |||||||||
1 | Orb-D1 G. David Low | Cygnus 1 Orbital Sciences COTS Demo Flight | Standard | 18 September 2013, 14:58:00 | Antares 110 | 1,299 lb (589 kg) | Success | [30] [31] [27] [32] | |
First Cygnus mission, first mission to rendezvous with ISS, first mission to berth with ISS, second launch of Antares. Docking to ISS delayed due to a computer data link problem, [33] which was later was resolved. [34] | |||||||||
2 | Orb-1 C. Gordon Fullerton | ![]() | Orbital-1 | Standard | 9 January 2014, 18:07:05 | Antares 120 | 2,780 lb (1,260 kg) | Success | [31] [27] [35] [32] |
First Commercial Resupply Service (CRS) mission for Cygnus, first Antares launch using the Castor 30B upper stage. | |||||||||
3 | Orb-2 Janice E. Voss | ![]() | Orbital Sciences CRS Flight 2 | Standard | 13 July 2014, 16:52:14 | Antares 120 | 3,293 lb (1,494 kg) | Success | [27] [32] |
4 | Orb-3 Deke Slayton | ![]() | Orbital Sciences CRS Flight 3 | Standard | 28 October 2014, 22:22:38 | Antares 130 | 4,883 lb (2,215 kg) | Failure | [36] [32] |
First Antares launch to use Castor 30XL upperstage. Suffered a catastrophic anomaly resulting in an explosion shortly after launch. Contents of the cargo included food and packages for the crew, parts, experiments, and the Arkyd-3 flight test system from Planetary Resources. | |||||||||
5 | OA-4 Deke Slayton II | ![]() | Orbital ATK CRS Flight 4 | Enhanced | 6 December 2015, 21:44:57 | Atlas V 401 | 7,746 lb (3,514 kg) | Success | [37] [38] [32] |
First Enhanced Cygnus mission. Orbital contracted with United Launch Alliance to launch this Cygnus on an Atlas V rocket from Cape Canaveral Air Force Station after damage to Antares launch pad after explosion. | |||||||||
6 | OA-6 Rick Husband | ![]() | Orbital ATK CRS Flight 6 | Enhanced | 23 March 2016, 03:05:52 | Atlas V 401 | 7,758 lb (3,519 kg) | Success | [37] [39] [38] [40] [32] |
Second mission to fly on an Atlas V. | |||||||||
7 | OA-5 Alan Poindexter | ![]() | Orbital ATK CRS Flight 5 | Enhanced | 17 October 2016, 23:45:36 | Antares 230 | 5,163 lb (2,342 kg) | Success | [41] [42] [43] |
Orbital had an option with United Launch Alliance to launch this mission on an Atlas V, but was not exercised. | |||||||||
8 | OA-7 John Glenn | ![]() | Orbital ATK CRS Flight 7 | Enhanced | 18 April 2017, 15:11:26 | Atlas V 401 | 7,443 lb (3,376 kg) | Success | [44] [45] [39] [38] [40] [32] |
9 | OA-8E Gene Cernan | ![]() | Orbital ATK CRS Flight 8 | Enhanced | 12 November 2017, 12:19:51 | Antares 230 | 7,359 lb (3,338 kg) | Success | [46] [45] [39] [38] [40] |
11 November 2017, launch was scrubbed just before launch when a general aviation aircraft entered the hazard zone and did not respond to calls. [47] | |||||||||
10 | OA-9E J.R. Thompson | ![]() | Orbital ATK CRS Flight 9 | Enhanced | 21 May 2018, 08:44:06 | Antares 230 | 7,385 lb (3,350 kg) | Success | [48] [49] |
First a commercial vehicle to perform ISS reboosting when, at 20:25 UTC on July 10, 2018, Cygnus's main engine was fired for about 50 seconds. Raised ISS altitude by about 295 ft (90 m). [50] | |||||||||
11 | NG-10 John Young | ![]() | Northrop Grumman CRS Flight 10 | Enhanced | 17 November 2018, 09:01:31 | Antares 230 | 7,386 lb (3,350 kg) | Success | [51] [52] |
12 | NG-11 Roger Chaffee | ![]() | Northrop Grumman CRS Flight 11 | Enhanced | 17 April 2019, 20:46:07 | Antares 230 | 7,575 lb (3,436 kg) | Success | [53] |
13 | NG-12 Alan Bean | ![]() | Northrop Grumman CRS Flight 12 | Enhanced | 2 November 2019, 13:59:47 | Antares 230+ | 8,221 lb (3,729 kg) | Success | |
14 | NG-13 Robert H. Lawrence | ![]() | Northrop Grumman CRS Flight 13 | Enhanced | 15 February 2020, 20:21:01 | Antares 230+ | 8,009 lb (3,633 kg) | Success | [54] |
9 February 2020 launch attempt scrubbed due to a ground support issue. [55] | |||||||||
15 | NG-14 Kalpana Chawla | ![]() | Northrop Grumman CRS Flight 14 | Enhanced | 3 October 2020, 01:16:14 | Antares 230+ | 7,624 lb (3,458 kg) | Success | [56] |
1 October 2020 launch attempt delayed due to boat in range, [57] later scrubbed due to a ground support issue. [58] | |||||||||
16 | NG-15 Katherine Johnson | ![]() | Northrop Grumman CRS Flight 15 | Enhanced | 20 February 2021, 17:36:50 | Antares 230+ | 8,400 lb (3,800 kg) | Success | |
17 | NG-16 Ellison Onizuka | ![]() | Northrop Grumman CRS Flight 16 | Enhanced | 10 August 2021, 22:01:05 | Antares 230+ | 8,208 lb (3,723 kg) | Success | [59] |
18 | NG-17 Piers Sellers | ![]() | Northrop Grumman CRS Flight 17 | Enhanced | 19 February 2022, 17:40:03 | Antares 230+ | 8,049 lb (3,651 kg) | Success | |
Performed the first operational reboost of ISS by a commercial vehicle on 25 June 2022 after it was aborted after few seconds on 20 June 2022. [60] [61] | |||||||||
19 | NG-18 Sally Ride | ![]() | Northrop Grumman CRS Flight 18 | Enhanced | 7 November 2022, 10:32:42 | Antares 230+ | 8,173 lb (3,707 kg) | Success | [62] [63] [64] |
6 November 2022 launch attempt scrubbed due to fire alarm in mission control. [65] | |||||||||
20 | NG-19 Laurel Clark | ![]() | Northrop Grumman CRS Flight 19 | Enhanced | 2 August 2023, 00:31:14 | Antares 230+ | 8,345 lb (3,785 kg) | Success | [66] [63] |
21 | NG-20 Patricia "Patty" Hilliard Robertson | ![]() | Northrop Grumman CRS Flight 20 | Enhanced | 30 January 2024, 17:07:15 | Falcon 9 Block 5 (B1077.10) ♺ | 8,345 lb (3,785 kg) | Success | [67] |
Northrop Grumman contracted with SpaceX to launch this Cygnus on a Falcon 9 Block 5 rocket from Cape Canaveral Space Force Station. | |||||||||
22 | NG-21 Francis R. "Dick" Scobee | ![]() | Northrop Grumman CRS Flight 21 | Enhanced | 4 August 2024, 15:02:23 | Falcon 9 Block 5 (B1080.10) ♺ | 8,503 lb (3,857 kg) | In orbit | [68] |
23 | NG-22 | Northrop Grumman CRS Flight 22 | Enhanced | February 2025 | Falcon 9 Block 5 | TBA | TBA | [69] | |
24 | NG-23 | Northrop Grumman CRS Flight 23 | Mission B | June 2025 | Antares 330 | TBA | TBA | [70] [2] | |
Scheduled to be the first flight of the Antares 330 and the larger Mission B Cygnus. | |||||||||
25 | NG-24 | Northrop Grumman CRS Flight 24 | Mission B | January 2026 [71] | Antares 330 | TBA | TBA | ||
26 | NG-25 | Northrop Grumman CRS Flight 25 | Mission B | 2026 [72] | Antares 330 | TBA | TBA | ||
Antares, known during early development as Taurus II, is an expendable launch system developed by Orbital Sciences Corporation and the Pivdenne Design Bureau to launch the Cygnus spacecraft to the International Space Station as part of NASA's COTS and CRS programs. Able to launch payloads heavier than 8,000 kg (18,000 lb) into low Earth orbit, Antares is the largest rocket operated by Northrop Grumman. Antares launches from the Mid-Atlantic Regional Spaceport and made its inaugural flight on April 21, 2013. Antares 100 was retired in 2014 and series 200 was retired in 2023 due to component unavailability. As of January 2024 Antares 300 is under development.
Commercial Resupply Services (CRS) are a series of flights awarded by NASA for the delivery of cargo and supplies to the International Space Station (ISS) on commercially operated spacecraft. The first CRS contracts were signed in 2008 and awarded $1.6 billion to SpaceX for twelve cargo Dragon and $1.9 billion to Orbital Sciences for eight Cygnus flights, covering deliveries to 2016. The Falcon 9 and Antares rockets were also developed under the CRS program to deliver cargo spacecraft to the ISS.
OA-5, previously known as Orbital-5, was the seventh planned flight of the Orbital Sciences' uncrewed resupply spacecraft Cygnus and its sixth flight to the International Space Station under the Commercial Resupply Services contract with NASA. The mission launched on 17 October 2016 at 23:45:36 UTC. Orbital Sciences 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, Orbital 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.
OA-6, previously known as Orbital-6, is the sixth flight of the Orbital ATK uncrewed resupply spacecraft Cygnus and its fifth flight to the International Space Station under the Commercial Resupply Services (CRS) contract with NASA. The mission launched on 23 March 2016 at 03:05:52 UTC.
OA-7, previously known as Orbital-7, is the eighth flight of the Orbital ATK uncrewed resupply spacecraft Cygnus and its seventh flight to the International Space Station (ISS) under the Commercial Resupply Services contract with NASA. The mission launched on 18 April 2017 at 15:11:26 UTC. Orbital 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 Services (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.
OA-8E was the ninth flight of the Orbital ATK uncrewed resupply spacecraft Cygnus and its eighth flight to the International Space Station (ISS) under the Commercial Resupply Services (CRS-1) contract with NASA. The mission launched on 12 November 2017 at 12:19:51 UTC. Orbital 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.
OA-9E was the tenth flight of the Cygnus, an uncrewed resupply spacecraft. The flight was launched by Orbital ATK (OA), which was purchased by Northrop Grumman during the mission. It was the ninth flight under the Commercial Resupply Services (CRS) contract with NASA and conducted under an extension, leading to the "E" in the mission name. The mission launched on 21 May 2018 at 08:44:06 UTC.
NG-10, previously known as OA-10E, is the eleventh flight of the Northrop Grumman uncrewed resupply spacecraft Cygnus and its tenth flight to the International Space Station under the Commercial Resupply Services (CRS-1) contract with NASA. The mission launched on 17 November 2018, at 09:01:31 UTC. This particular mission is part of an extension of the initial CRS contract that enables NASA to cover the ISS resupply needs until the Commercial Resupply Services-2 (CRS-2) contract enters in effect.
NG-11, previously known as 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 (CRS-1) contract with NASA. The mission launched on 17 April 2019 at 20:46:07 UTC. This is the last mission from the extended CRS-1 contract; follow-up missions are part of the CRS-2 contract. Cygnus NG-11 was also the first mission to load critical hardware onto Cygnus within the last 24 hours prior to launch, a new Antares feature.
NG-12, previously known as OA-12, was the thirteenth flight of the Northrop Grumman robotic resupply spacecraft Cygnus and its twelfth Commercial Resupply Services flight to the International Space Station (ISS) for NASA. The mission launched on 2 November 2019 at 13:59:47 UTC). This was the first launch of Cygnus under the Commercial Resupply Services 2 (CRS-2) contract.
NG-13, previously known as OA-13, was the fourteenth flight of the Northrop Grumman robotic resupply spacecraft Cygnus and its thirteenth flight to the International Space Station (ISS) under the Commercial Resupply Services (CRS-1) contract with NASA. The mission launched on 15 February 2020 at 20:21:01 UTC after nearly a week of delays. This is the second launch of Cygnus under the CRS-2 contract.
NG-14, previously known as OA-14, was the fifteenth flight of the Northrop Grumman robotic resupply spacecraft Cygnus and its fourteenth flight to the International Space Station under the Commercial Resupply Services (CRS-1) contract with NASA. The mission was launched on 3 October 2020, at 01:16:14 UTC.
NG-15, previously known as OA-15, was the fifteenth launch of the Northrop Grumman robotic resupply spacecraft Cygnus and its fourteenth flight to the International Space Station (ISS) under the Commercial Resupply Services (CRS) contract with NASA. The mission launched on 20 February 2021 at 17:36:50 UTC. This is the fourth launch of Cygnus under the CRS-2 contract.
NG-16, previously known as OA-16, was the sixteenth flight of the Northrop Grumman robotic resupply spacecraft Cygnus and its fifteenth flight to the International Space Station (ISS) under the Commercial Resupply Services (CRS-2) contract with NASA. The mission was launched on 10 August 2021 at 22:01:05 UTC, for a (planned) 90-day mission at the ISS. This was the fifth launch of Cygnus under the CRS-2 contract.
NG-17, previously known as OA-17, was the seventeenth flight of the Northrop Grumman robotic resupply spacecraft Cygnus and its sixteenth flight to the International Space Station (ISS) under the Commercial Resupply Services (CRS) contract with NASA. The mission launched on 19 February 2022 at 17:40:03 UTC. It was the sixth launch of Cygnus under the CRS-2 contract.
NG-18 was the eighteenth flight of the Northrop Grumman robotic resupply spacecraft Cygnus and its seventeenth flight to the International Space Station (ISS) under the Commercial Resupply Services (CRS-2) contract with NASA. The mission successfully launched on 7 November 2022 at 10:32:42 UTC. This was the seventh launch of Cygnus under the CRS-2 contract.
NG-19 was the nineteenth flight of the Northrop Grumman robotic resupply spacecraft Cygnus and its eighteenth flight to the International Space Station (ISS) under the Commercial Resupply Services (CRS-2) contract with NASA. The mission launched on 2 August 2023 at 00:31:14 UTC. This was the eighth launch of Cygnus under the CRS-2 contract.
NG-20 was the twentieth flight of the Cygnus, an expendable American cargo spacecraft used for International Space Station (ISS) logistics missions that launched on 30 January 2024 and was deorbited on 13 July 2024. It was operated by Northrop Grumman under a Commercial Resupply Services contract with NASA. The spacecraft was an Enhanced Cygnus, named the S.S. Patricia "Patty" Hilliard Robertson in honor of the NASA astronaut who died in a plane crash prior to being assigned to a crew to fly to the ISS.
NG-21 is the twenty-first flight of the Cygnus, an expendable American cargo spacecraft used for International Space Station (ISS) logistics missions, that launched on 4 August 2024. It is operated by Northrop Grumman under a Commercial Resupply Services contract with NASA. The spacecraft is an Enhanced Cygnus, named the S.S. Francis R. "Dick" Scobee in honor of the NASA astronaut who died in the Space Shuttle Challenger disaster.