USA-171

USA-171

Launch of USA-171
Mission type	SIGINT
Operator	NRO/CIA
COSPAR ID	2003-041A
Spacecraft properties
Spacecraft type	Orion
Manufacturer	Northrop Grumman
Start of mission
Launch date	9 September 2003 04:29 UTC
Rocket	Titan IV (401)B/Centaur-T (B-36/TC-20)
Launch site	Cape Canaveral, SLC-40
Contractor	Lockheed Martin
Orbital parameters
Reference system	Geocentric orbit
Regime	Geosynchronous orbit
Orion Series ←  USA-139 (Orion-4) USA-202 (Orion-6) →

USA-171 (also known Orion-5, Homer and NROL-19) is an American SIGINT reconnaissance satellite which is operated by the National Reconnaissance Office. Launched in September 2003, it is the secret Orion satellite. ^{[1] [2] [3] [4]}

Overview

This is the last Orion satellite launch on Titan IV rocket and last launch of Titan IV (401)B/Centaur-T Version and last Titan IV launch with extremely long metallic fairing and future Orion mission will launch on the Delta IV Heavy rocket. ^[5]

Orion also known as Mentor is a SIGINT/ELINT satellite build to replace Magnum satellite ^[6] and the COMINT capability also made Orion a replacement for the Mercury satellite. ^[7] It is called that the satellite has a reflector of a diameter as big as ~100m ^{[8] [9]}

See also

• Spaceflight portal

• List of USA satellites
• List of NRO Launches

References

1. "Orion 5, 6, 7, 8, 9, 10, 11, 12". Gunter's Space Page. Retrieved 16 October 2025.
2. "Orion 5 (USA-171) (NROL-19) | Titan IV(401)B | Next Spaceflight". nextspaceflight.com. Retrieved 18 October 2025.
3. "National Reconnaissance Office Launch (NROL) series satellites". rammb.cira.colostate.edu. Retrieved 18 October 2025.
4. "Titan IVB | NROL-19 Mission". RocketLaunch.org. Retrieved 18 October 2025.
5. "Orion 5 (USA-171) (NROL-19) | Titan IV(401)B | Next Spaceflight". nextspaceflight.com. Retrieved 18 October 2025.
6. "Orion 1, 2 (Magnum 1, 2)". Gunter's Space Page. Retrieved 19 October 2025.
7. "Mercury 14, 15, 16 ('Advanced Vortex 1, 2, 3')". Gunter's Space Page. Retrieved 18 October 2025.
8. "Orion 5, 6, 7, 8, 9, 10, 11, 12". Gunter's Space Page. Retrieved 16 October 2025.
9. "Advanced Orion". www.astronautix.com. Retrieved 17 October 2025.