 Enhanced Cygnus spacecraft approaching theInternational Space Station for theNG-12 mission | |
| Manufacturer |
|
|---|---|
| Country of origin | United States |
| Operator |
|
| Applications | ISS resupply |
| Specifications | |
| Spacecraft type | Cargo |
| Bus | GEOStar |
| Dry mass | |
| Payload capacity | |
| Volume | |
| Power | 3.5 kW |
| Design life | 1 week to 2 years[1] |
| Dimensions | |
| Length | |
| Diameter | 3.07 m (10.1 ft)[2] |
| Production | |
| Status | In service |
| On order | 3 |
| Built | 23 |
| Launched | 23 |
| Operational | 1 (NG-23) |
| Retired | 21 |
| Lost | 1 (Orb-3) |
| Maiden launch | September 18, 2013 |
| Last launch | September 14, 2025(most recent) |
| Related spacecraft | |
| Launch vehicle | Antares,Atlas V,Falcon 9 |
Cygnus is anexpendable Americanuncrewed cargo spacecraft developed forInternational Space Station (ISS) resupply missions. It was originally built byOrbital Sciences Corporation with financial support fromNASA under theCommercial Orbital Transportation Services (COTS) program. The spacecraft consists of a pressurized cargo module—based largely on theMulti-Purpose Logistics Module and built byThales Alenia Space—paired with a service module derived from Orbital'sGEOStar, asatellite bus. Following a successful demonstration flight in 2013, Orbital was awarded aCommercial Resupply Services (CRS) contract.
Over time, Cygnus has been upgraded to increase its size and capabilities. TheEnhanced Cygnus variant debuted in 2015, and the further enlargedCygnus XL entered service in 2025. Features added over time includereboost capability to raise the ISS orbit, the ability to support late cargo loading shortly before launch, and the option to conduct secondary missions after undocking. Each mission ends with a controlled destructive reentry, which also provides a means of disposing of waste generated aboard the station. Alongside Cygnus, other ISS resupply spacecraft have included the RussianProgress, the EuropeanAutomated Transfer Vehicle, the JapaneseH-II Transfer Vehicle, and the AmericanSpaceX Dragon.
Cygnus is typically launched on its parent company’sAntares rocket from theWallops Flight Facility in Virginia, but it can also fly aboard other launch vehicles. After an Antares failure destroyedCygnus CRS Flight 3 and damaged Wallops in 2014, two subsequent missions launched onAtlas V rockets in 2015 and 2016. More recently, Cygnus missions have been launched onFalcon 9 rockets in 2024 and 2025, with another planned for 2026, under arrangements with CRS competitorSpaceX. The nameCygnus derives from theGreek word forswan and refers to theconstellation.
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 itsCommercial Orbital Transportation Services (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 October 18, 2007, NASA announced it would terminate its contract and re-award it after a second competition.[6][7]
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'sStar Bus, asatellite bus in use since 1997, which would be attached to a pressurized cargo module built byThales Alenia Space, which had also built theMPLM cargo module used by the Space Shuttle, the cargo module for the EuropeanATV spacecraft and several permanent modules on the ISS.[8]
Cygnus was awarded a COTS contract worth $170 million in February 2008, which was later increased to $288 million. 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 agreed to deliver up to 20 tons of cargo to the ISS through 2016 in eight Cygnus spacecraft flights.[9]
To propel Cygnus into space, Orbital developed theAntares rocket, which also leveraged lower-cost, off-the-shelf parts and designs. Construction and design of the first stage was subcontracted to Ukrainian companies and usedrefurbishedNK-33 engines, remnants of the SovietN1 moon rocket. The second stage was theCastor 30, which Orbital had previously used on another rocket project (theMinotaur-C) and was based on aPeacekeeper ICBM first stage.
The first Cygnus flight was originally planned to occur in December 2010, but was repeatedly delayed.[10][11] 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.[12] On January 12, 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.[12][13]
With the December 2015 launch ofOrb 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, theOrb 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).[14]
.jpg)
.jpg)
.jpg)
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 theGEOStar andLEOStar (collectively known asStar Bus)satellite buses and theDawn spacecraft. It has a gross mass of 1,800 kg (4,000 lb), 32 thrusters for attitude control and oneBT-4 main engine[15] fueled with around 800 kilograms (1,800 lb) ofhypergolic propellants,hydrazine andnitrogen tetroxide.[16][17] The SM is capable of producing 3.5 kW of electrical power via two solar arrays.[18][19] During a mission, Cygnus maneuvers close to the International Space Station, where theCanadarm2 robotic armgrapples the spacecraft andberths it to aCommon Berthing Mechanism, typically the nadir (Earth facing) port of theUnity module.[18]
The Pressurized Cargo Module (PCM) is manufactured by Thales Alenia Space inTurin, Italy and has been produced in several variants. The initial Standard PCMs were 5.14 meters (16.9 ft) long, with a 2,000 kilograms (4,400 lb) payload capacity and 18.9 cubic meters (670 cu ft) of pressurized volume.[18] The Enhanced variant, introduced with the fourth Cygnus spacecraft, features a stretched PCM that is 6.39 meters (21.0 ft) long, increasing the payload capacity to 3,500 kilograms (7,700 lb), a 32% increase, and the volume to 27 cubic meters (950 cu ft), a 19.5% increase.[20] Starting with the Enhanced variant, the solar panels were also upgraded to the UltraFlex, an accordion fanfold array, and the fuel load was increased to 1,218 kilograms (2,685 lb). Announced in August 2023, the even larger Cygnus XL began service with the NG-23 mission in September 2025.[4][21] It measures 7.89 meters (25.9 ft) in length, carries a 5,000-kilogram (11,000 lb) payload, a 19.5% increase, and provides 36 cubic meters (1,300 cu ft) of volume (a 15.5% increase).[4]
An earlier proposed version of Cygnus would have replaced the PCM with the Unpressurized Cargo Module (UCM), based on NASA'sExPRESS Logistics Carrier, and would have been used to transport unpressurized cargo, such asISS Orbital Replacement Units.[10][22] Another proposed variant would have replaced the PCM with the Return Cargo Module (RCM), which would have allowed Cygnus to return cargo to Earth.[10]
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 adestructive reentry.[23]
In August 2019, NASA decided to sole source its design for the Minimal Habitation Module (Habitation and Logistics Outpost, or HALO) of theLunar 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[24][25] 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.[26][27] On June 5, 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 byMaxar.[26][27]
The following list includes only missions that have flown and six planned missions. As of August 2024[update] one more mission is planned to be launched on theFalcon 9 rocket fromCape Canaveral Space Launch Complex 40, and three from Wallops on anAntares 330. Cygnus is the only cargo freighter to launch on four different launch vehicles: theAntares 100 series,Atlas V,Antares 200 series andFalcon 9 Block 5.[28] Each mission is named for a notable member of the Human spaceflight community.
| # | Mission | Patch | Launch date (UTC) | Launch vehicle | Variant | Payload mass | Outcome | Ref. |
|---|---|---|---|---|---|---|---|---|
| 1 | Orb-D1 G. David Low | (patch) | September 18, 2013, 14:58:00 | Antares 110 | Standard | 1,299 lb (589 kg) | Success | [29][30][31][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 |  | January 9, 2014, 18:07:05 | Antares 120 | Standard | 2,780 lb (1,260 kg) | Success | [30][31][35][32] |
| First Commercial Resupply Service (CRS) mission for Cygnus, first Antares launch using theCastor 30B upper stage. | ||||||||
| 3 | Orb-2 Janice E. Voss |  | July 13, 2014, 16:52:14 | Antares 120 | Standard | 3,293 lb (1,494 kg) | Success | [31][32] |
| 4 | Orb-3 Deke Slayton |  | October 28, 2014, 22:22:38 | Antares 130 | Standard | 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, damaging launch pad. Contents of the cargo included food and packages for the crew, parts, experiments, and theArkyd-3 flight test system fromPlanetary Resources. | ||||||||
| 5 | OA-4 Deke Slayton II |  | December 6, 2015, 21:44:57 | Atlas V 401 | Enhanced | 7,746 lb (3,514 kg) | Success | [37][38][32] |
| First flight of Enhanced Cygnus spacecraft. Due to damage at launch pad after the explosion of the Antares rocket carrying Orb-3, Orbital contracted withUnited Launch Alliance to launch this Cygnus on anAtlas V rocket fromCape Canaveral Air Force Station. First of three missions to fly on an Atlas V rocket. | ||||||||
| 6 | OA-6 Rick Husband |  | March 23, 2016, 03:05:52 | Atlas V 401 | Enhanced | 7,758 lb (3,519 kg) | Success | [37][39][38][40][32] |
| Second of three missions to fly on an Atlas V rocket. | ||||||||
| 7 | OA-5 Alan Poindexter |  | October 17, 2016, 23:45:36 | Antares 230 | Enhanced | 5,163 lb (2,342 kg) | Success | [41][42][43] |
| First flight of an Antares 200 series rocket. | ||||||||
| 8 | OA-7 John Glenn |  | April 18, 2017, 15:11:26 | Atlas V 401 | Enhanced | 7,443 lb (3,376 kg) | Success | [44][45][39][38][40][32] |
| Third of three missions to fly on an Atlas V rocket. | ||||||||
| 9 | OA-8E Gene Cernan |  | November 12, 2017, 12:19:51 | Antares 230 | Enhanced | 7,359 lb (3,338 kg) | Success | [46][45][39][38][40] |
| November 11, 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 |  | May 21, 2018, 08:44:06 | Antares 230 | Enhanced | 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 |  | November 17, 2018, 09:01:31 | Antares 230 | Enhanced | 7,386 lb (3,350 kg) | Success | [51][52] |
| 12 | NG-11 Roger Chaffee |  | April 17, 2019, 20:46:07 | Antares 230 | Enhanced | 7,575 lb (3,436 kg) | Success | [53] |
| 13 | NG-12 Alan Bean |  | November 2, 2019, 13:59:47 | Antares 230+ | Enhanced | 8,221 lb (3,729 kg) | Success | |
| 14 | NG-13 Robert H. Lawrence |  | February 15, 2020, 20:21:01 | Antares 230+ | Enhanced | 8,009 lb (3,633 kg) | Success | [54] |
| February 9, 2020, launch attempt scrubbed due to a ground support issue.[55] | ||||||||
| 15 | NG-14 Kalpana Chawla |  | October 3, 2020, 01:16:14 | Antares 230+ | Enhanced | 7,624 lb (3,458 kg) | Success | [56] |
| October 1, 2020, launch attempt delayed due to boat in range,[57] later scrubbed due to a ground support issue.[58] | ||||||||
| 16 | NG-15 Katherine Johnson |  | February 20, 2021, 17:36:50 | Antares 230+ | Enhanced | 8,400 lb (3,800 kg) | Success | |
| 17 | NG-16 Ellison Onizuka |  | August 10, 2021, 22:01:05 | Antares 230+ | Enhanced | 8,208 lb (3,723 kg) | Success | [59] |
| 18 | NG-17 Piers Sellers |  | February 19, 2022, 17:40:03 | Antares 230+ | Enhanced | 8,049 lb (3,651 kg) | Success | |
| Performed the first operational reboost of ISS by a commercial vehicle on June 25, 2022, after it was aborted after few seconds on June 20, 2022.[60][61] | ||||||||
| 19 | NG-18 Sally Ride |  | November 7, 2022, 10:32:42 | Antares 230+ | Enhanced | 8,173 lb (3,707 kg) | Success | [62][63][64] |
| November 6, 2022, launch attempt scrubbed due to fire alarm in mission control.[65] | ||||||||
| 20 | NG-19 Laurel Clark |  | August 2, 2023, 00:31:14 | Antares 230+ | Enhanced | 8,345 lb (3,785 kg) | Success | [66][63] |
| Final flight on an Antares 200 series rocket. | ||||||||
| 21 | NG-20 Patricia "Patty" Hilliard Robertson |  | January 30, 2024, 17:07:15 | Falcon 9 Block 5 (B1077-10) | Enhanced | 8,345 lb (3,785 kg) | Success | [67] |
| Northrop Grumman contracted withSpaceX to launch this Cygnus on aFalcon 9 Block 5 rocket fromCape Canaveral Space Force Station. First of four missions to fly on a Falcon 9 Block 5 rocket. | ||||||||
| 22 | NG-21 Francis R. "Dick" Scobee |  | August 4, 2024, 15:02:23 | Falcon 9 Block 5 (B1080-10) | Enhanced | 8,503 lb (3,857 kg) | Success | [68] |
| Second of four missions to fly on a Falcon 9 Block 5 rocket. | ||||||||
| 23 | NG-23 William "Willie" C. McCool |  | September 14, 2025, 22:11 | Falcon 9 Block 5 (B1094‑4) | XL | 10,827 lb (4,911 kg) | In progress | [4][69][70][71] |
| The NG-23 mission was the first flight of the extended Cygnus XL spacecraft and the third of four planned missions to fly on a Falcon 9 Block 5 rocket. During the flight, the spacecraft's planned engine burns were unexpectedly cut short, causing a delay in its arrival at the ISS. | ||||||||
| 25 | NG-24 TBA | H1 2026 | Falcon 9 Block 5 | XL | TBA | Planned | [72] | |
| Fourth of four missions to fly on a Falcon 9 Block 5 rocket.[73] | ||||||||
| 26 | NG-22 TBA | TBA | Antares 330 | Enhanced | TBA | Planned | [74] | |
| Originally scheduled to fly in January 2025, but delayed until June due to avionics issue. Cargo module damaged during shipment to Cape Canaveral which has indefinitely delayed the launch.[75][76] | ||||||||
| 27 | NG-25 TBA | 2026 | Antares 330 | XL | TBA | Planned | [77] | |
This article incorporates text from this source, which is in thepublic domain.
| Launch vehicles |  | |
|---|---|---|
| Operators | ||
| Past missions |
| |
| Current missions |
| |
| Future missions | ||
| ||
| Active |  | |
|---|---|---|
| In development | ||
| Retired | ||
| Proposed | ||
| Cancelled | ||
| Origins | ||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Support vehicles |
| |||||||||||||||||||||||||||||||
| Mission control | ||||||||||||||||||||||||||||||||
| Administrative | ||||||||||||||||||||||||||||||||
| Documentaries |
| |||||||||||||||||||||||||||||||
| Related |
| |||||||||||||||||||||||||||||||
| ||||||||||||||||||||||||||||||||
| ||||||||||||||||||||||||||||||||
| ||||||||||||||||||||||||||||||||
| ||||||||||||||||||||||||||||||||
