USSF-51

USSF-51

USSF-51 Launch
Operator	USSF
Start of mission
Launch date	30 July 2024 10:45 UTC
Rocket	Atlas V 551 (AV-101)
Launch site	Cape Canaveral, SLC-41
Contractor	United Launch Alliance
Orbital parameters
Reference system	Geocentric orbit
Regime	Geosynchronous orbit
USSF Launch ← USSF-62 USSF-106 →

USSF-51 is an American National Security Space Launch Mission under the vision of United States Space Force. The launch is significant as it is the Last launch for United Launch Alliance's Atlas V rocket for National Security Mission. After reaching orbit Three Satellite are deployed named USA-396, USA-397 and USA-398. In October 2025, one more satellite is deployed named USA-566.^{[1][2][3][4][5][6][7][8]}

Overview

USSF had assigned USSF-106 Mission to ULA in 2020. At the time it was planned to be the first National Security Mission on Vulcan Centaur but after reassignment to an Atlas V, USSF-106 become the first National Security Mission on Vulcan Centaur.^[9]

This mission is also last use of Russian RD-180 engine on US National Security Missions which is used on ULA's Atlas V rocket and is replaced with American made BE-4 engines, two of them is used on ULA's Vulcan Centaur rocket starting with USSF-106 Mission in August 2025.^[10]

See also

• Spaceflight portal

• List of USA satellites
• List of USSF launches
• National Security Space Launch

References

1. "USSF-51 (USA-396 to 398) | Atlas V 551 | Next Spaceflight". nextspaceflight.com. Retrieved 16 October 2025.
2. Davenport, Justin (29 July 2024). "Atlas V successfully launched its last ever national security mission". NASASpaceFlight.com. Retrieved 16 October 2025.
3. "ULA launches Atlas 5 rocket on the company's 100th national security mission – Spaceflight Now". Retrieved 16 October 2025.
4. updated, Mike Wall last (29 July 2024). "Atlas V rocket launches its final national security mission for US military (video)". Space. Retrieved 16 October 2025. {{cite web}}: |last= has generic name (help)
5. "Atlas V USSF-51". www.ulalaunch.com. Retrieved 16 October 2025.
6. ULA. "United Launch Alliance Successfully Launches 100th National Security Mission". newsroom.ulalaunch.com. Retrieved 16 October 2025.
7. "USA 396, 397, 398 (USSF 51)". Gunter's Space Page. Retrieved 16 October 2025.
8. "USSF-51 (USA-396 to 398) | Atlas V 551 | Next Spaceflight". nextspaceflight.com. Retrieved 17 October 2025.
9. "FY20 NSS Missions". U.S. Air Force. 7 August 2020. Retrieved 11 June 2023.
10. Ferster, Warren (17 September 2014). "ULA To Invest in Blue Origin Engine as RD-180 Replacement". SpaceNews. Archived from the original on 18 September 2014. Retrieved 19 September 2014.

• Bergin, Chris. "NASASpaceFlight.com".
• Clark, Stephen. "Spaceflight Now".
• Kelso, T.S. "Satellite Catalog (SATCAT)". CelesTrak.
• Krebs, Gunter. "Chronology of Space Launches".
• Kyle, Ed. "Space Launch Report". Archived from the original on 5 October 2009. Retrieved 13 August 2022.
• McDowell, Jonathan. "GCAT Orbital Launch Log".
• Pietrobon, Steven. "Steven Pietrobon's Space Archive".
• Wade, Mark. "Encyclopedia Astronautica".
• Webb, Brian. "Southwest Space Archive".
• Zak, Anatoly. "Russian Space Web".
• "ISS Calendar". Spaceflight 101.
• "NSSDCA Master Catalog". NASA Space Science Data Coordinated Archive. NASA Goddard Space Flight Center.
• "Хроника освоения космоса" [Chronicle of space exploration]. CosmoWorld (in Russian).
• "Rocket Launch Manifest". Next Spaceflight.
• "Space Launch Plans". Novosti Kosmonavtiki.
• "Space Satellite Tracking". N2YO.

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