NASA Abbreviations and Acronyms

1. ORR
   Operations Requirements Review
2. ORR
   Operation Readiness Review
3. ORR
   Orroral Valley, Australia Gstdn Tracking Station
4. ORS
   Orroval Valley
5. ORSC
   Oxygen-Rich Staged Combustion
6. ORSDI
   Oak Ridge Selective Dissemination of Information
7. ORTHOG
   Orthogonal
8. ORU
   Orbital Replacement Unit
9. ORUC
   Oru Carrier
10. OS
    Operating System
11. OS
    On-Line System
12. OS
    Optics Subsystem
13. OS
    on-orbit station
14. OS
    Orbiter Cei Specification
15. OSA
    Operational Support Area
16. OSC
    Oscillator
17. OSC
    Office of Space Communications
18. OSC
    Orbital Science Corporation
19. OSCAT
    Indian Space Agency's Scatterometerminstrument
20. OSCIL
    Oscillator

Last updated: May 6, 2025 — Total entries: 14,020