Cygnus NG-21

***NG-21*** is the twenty-first flight of the **Cygnus**, an expendable American cargo spacecraft used for International Space Station (ISS) logistics missions. It launched on 4 August 2024.

NG-21 is the tenth Cygnus mission operated by Northrop Grumman under a contract with NASA.

## History

Cygnus was developed by Orbital Sciences Corporation and partially funded by NASA. The NG-21 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.

### Replacement of Antares 230+ rockets

NG-21 is the second launch of a Cygnus spacecraft after Northrop Grumman ran out of its Antares 230+ rockets. The Antares used a Russian-built engine and Ukrainian-built first stage, and production ceased after the Russian invasion of Ukraine.

In response, Northrop Grumman began planning to use its next-generation Antares 300 rocket, which does not depend on Ukrainian or Russian parts, to fly NG-23. In the meantime, the company contracted with its CRS competitor SpaceX to launch NG-20, 21 and 22 using its Falcon 9 Block 5 rocket.

## Development

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. The larger Enhanced Cygnus was introduced in 2015.

Orbital Sciences was renamed Orbital ATK in 2015. Northrop Grumman purchased Orbital in 2018 and has continued to operate Cygnus missions.

## Production and operations

Cygnus spacecraft are produced and put together in Dulles, Virginia. Once it arrives at the launch site, the Cygnus service module is paired with the pressurized cargo module. NG-21 was the sixteenth flight of the Enhanced-sized Cygnus Pressurized Cargo Module.

Mission operations are conducted from control centers in Dulles, Virginia and Houston, Texas.

## Infobox (spaceflight/dock)

- **docking type**: Berth
- **docking target**: ISS
- **docking port**: Unity nadir
- **capture date**: 6 August 2024,
 07:10 UTC (planned)
- **docking date**: 6 August 2024,
 07:10 UTC (planned)


## Infobox (spaceflight)

- **name**: NG-21
- **image**: NG-21_Encapsulation.jpg
- **image caption**: The S.S Francis R. "Dick" Scobee (NG-21) spacecraft being encapsulated inside the SpaceX Falcon 9 payload fairing as it prepares to launch
- **mission type**: ISS logistics
- **operator**: Northrop Grumman
- **cospar id**: 2024-139A
- **satcat**: 60378
- **mission duration**:
 (in progress)
- **spacecraft**: S.S. Francis R. "Dick" Scobee
- **spacecraft type**: Enhanced Cygnus
- **manufacturer**: Northrop Grumman
 Thales Alena
- **launch date**: 4 August 2024,
 15:02:00 UTC
 (11:02 am EDT)
- **launch rocket**: Falcon 9 Block 5
 (B1080.10)
- **launch site**: Cape Canaveral, SLC-40
- **launch contractor**: SpaceX
- **disposal type**: Deorbited
- **decay date**: January 2025 (planned)
- **orbit reference**: Geocentric orbit
- **orbit regime**: Low Earth orbit
- **orbit inclination**: 51.66°
- **payload items**: Cargo
- **cargo mass**: 3,857 kg (8,503 lb)
- **cargo mass press**: 3,843 kg (8,472 lb)
- **cargo mass unpress**: 14 kg (31 lb)
- **insignia**: Cygnus_NG-21_Patch.png
- **insignia caption**: Cygnus NG-21 Patch
- **programme**: Commercial Resupply Services
- **previous mission**: SpaceX CRS-30
- **next mission**: SpaceX CRS-31
- **programme2**: Cygnus flights
- **previous mission2**: NG-20
- **next mission2**: NG-22